AF447 [Archive] - Page 10

CapitainKirk

24th Jun 2009, 19:23

Been a lurker here for a few years now and no longer sitting up the pointy end i am seriously concerned about what i am reading here.

Never been a V1 Positive Climb Gear Up Autopilot On pilot - and yes i tended to hand fly up to cruising height and on the way down from TOD around 95% of the time and occasionally in the cruise too where there was more to do than fly straight and level for and length of time and yes i have had the CSC (that should give you a hint - along with the lovely Tartan skirts) come on the flight deck to see/ask why things were not as smooth as normal. I am seriously worried about the hands on skills of the people who are flying me about now. Doubly so as i cant now get on the FD. And yes i have been there as a retiree (i know – I hat(ed) being back in the cabin) too when the F/O and then the Cpt took rest mid Atlantic on a 747-400 on a LHR to LAX flight. This was after having to abort and return to LHR on the previous day due to C/B's on the main and aux bus tripping. Then while the passengers were put up close to LHR the crew were bussed 60 miles away to get what must have been minimum rest at best - all from your Fave Airline :-I did have a wee shot of i think a 310 and i found that quite strange being used to the other style of fly by wire aircraft. Yes i have sat reading the Guardian and the Telegraph on many a Transatlantic flight and yes we had an open cockpit policy ask and generally FD visits were more than possible for sure they helped to relieve the boredom. My nasty weather experiences have mostly been in FL slaloming round the thunderheads in VFR conditions and we always ADVISED a 20/30 degree course change to avoid weather and never once had a problem from ATC and of course some in Europe too on the Ski flights. I am rambling. It would appear - please dont take this the wrong way - but the skills are gone/going fast from the job now - pilots are increasing 'just' monitoring systems and dont have the skills or the experience to take over when the **** hits the N1. Also it would appear that we are entering a period when the experienced captains are retiring to be replaced by people who jump from a PPL into a ATPL without any real flying skills. Is this fixable i cant see how - maybe others can see a solution. Flying now is a worry to me and when i hear rubbish from the flight deck like "sorry our departure was late but we will make it up as we cross the Atlantic" aye right quickly file a new flight plan with .85 as the new cruising speed and "sorry we did not make up time crossing the Atlantic but we will get a straight in to NY" again utter rubbish - a downwind landing against the existing traffic flow - and when I look out the window and see the air brakes at half cock and after 30 mins they are still like that - then i mention this to the FA and get told “its ok sir the Captain knows" and watch her walk down to the aft galley pick up the inter phone and immediately the speed brakes are closed as the SB handle gets latched in the closed position properly- i do wonder where this industry is going.

ACLS65

24th Jun 2009, 19:34

woodja51: There is a recent article in the latest FRAeS magazine 'out of the fog ' by a Capt Robert Scott.

Is there any online link to this? I keep finding Robert Scott the early 1900's Antarctic explorer instead.

I think you make some very good points, regarding the complexity of modern FCS, and a probable drift of skills more towards computer operator/systems diagnostician than reflexive pilot.

One key question will be whether situation was one that anyone, pilot or computer could have recovered from. It is possible that it was a recoverable upset per some of the other A330 upsets, made worse by weather, information overload, etc.

Another possibility is that the situation was completely beyond anyone's ability to recover from and the similarities to the other A330 upsets is only a component of the issue or coincidence (for example probe icing followed by structural failure).

I will try and find the doc again, but it that really put the loss of computers/automation/instruments into perspective for me, it mentioned that one way if you have conflicting information was to compare air speed to cockpit wind noise. How quickly things can get back to basics, and imagine that mid storm, mid crisis.

If we forgoe the piloting skills we reach the other extreme that is 2001-esqe. "Please save the plane HAL. I'm sorry Dave, I can't do that."

Somewhere in between is the fine balance that gives us the benefits and minimizes the risks.

RealQuax

24th Jun 2009, 19:35

@ FrequentSLF:

Accepted catastrophic failure-rates are actually much higher:
The 10E-9 - figure is the failure-rate of _one_ system leading to a catastrophic failure.
Given an error-(failure-)chain, the accepted probability is 10E-6. This accident is most probably in this category.

The source is AMC 25.1309. ("Acceptable means of compliance to Certification Specification 25")
I cite the explanation:
In assessing the acceptability of a design it was recognised that rational probability values would have to be established. Historical evidence indicated that the probability of a serious accident due to operational and airframe-related causes was approximately one per million hours of flight. Furthermore, about 10 percent of the total were attributed to Failure Conditions caused by the aeroplane's systems. It seems reasonable that serious accidents caused by systems should not be allowed a higher probability than this in new aeroplane designs. It is reasonable to expect that the probability of a serious accident from all such Failure Conditions be not greater than one per ten million flight hours or 1 x 10-7 per flight hour for a newly designed aeroplane. The difficulty with this is that it is not possible to say whether the target has been met until all the systems on the aeroplane are collectively analysed numerically. For this reason it was assumed, arbitrarily, that there are about one hundred potential Failure Conditions in an aeroplane, which could be Catastrophic. The target allowable Average Probability per Flight Hour of 1 x 10-7 was thus apportioned equally among these Failure Conditions, resulting in an allocation of not greater than 1 x 10-9 to each. The upper limit for the Average Probability per Flight Hour for Catastrophic Failure Conditions would be 1 x 10-9 , which establishes an approximate probability value for the term "Extremely Improbable". Failure Conditions having less severe effects could be relatively more likely to occur.

Thomas

Dysag

24th Jun 2009, 19:39

Maybe it's contracting.
Boeing and Airbus would never agree, but will the 90% of pax travelling on family trips always be there? When one can see one's granny in Australia large as life (yuk) every day, where's the incentive to fly sardine class for 20+ hrs?
I'm a veteran but I feel a revolution is in the air.

BarbiesBoyfriend

24th Jun 2009, 19:40

Capitain Kirk

I agree with you. The job has been de-skilled and ever more rigorous SOPs have been substituted for airmanship.

The upside has to be considered too though, does it not?

Flight safety has generally been improving.:ok:maybe in part due to strict adherence to those SOPs

Recent events indicate that, as always, perhaps the pendulum has swung too far.

Now we've great SOP adherents, who rarely fly and believe the SOP will protect them- which it does! ...........until it doesn't.

They then have little else to fall back on.:sad:

kuningan

24th Jun 2009, 19:51

There is almost no good in debating all these smashed seats and entertainment systems and oxygen bottles and on and on.

Even if it provides some potential insight into the crash and or break up sequence?

Of course the professional investigators will do their jobs - thoroughly - and take time to do it.

In the mean time, from the sizes and identifiability of the debris we clearly know that we are not dealing with an MI185.....earlier speculation had explored the loss of the tail....relatively intact debris from the front of the plane suggests other options.....this is, after all a rumour network.....

AMF

24th Jun 2009, 20:26

DJ77 AMG65 and AMF

But AMF's description should be supported by references to theoretical or experimental studies or even personal experience (if any). Otherwise, it looks like fiction.

See, for example, Tim Vasquez's analysis: no updraft higher than 40kt (about 4000 ft/mn), not "18000 ft/min, even higher" as mentioned, and no heat sink signature observed.

Of course, I don't intend to suggest that the pilots were not faced with a very severe situation flying in (or close to) bad weather without reliable airspeed indication.

I've already posted on this and the previous thread the basics of high altitude aerodynamics, and given the approximated weight of that aircraft at 35,000' others have referenced the buffet margins and turb air penetration speed they'd be dealing with. My question to you would be have you ever actually hand-flown a jet aircraft near the upper limit of it's performance envolope in smooth, still air, let alone with moderate or higher turbulence? Your answer makes me doubt that very much.

And if you're downplaying an aircraft traveling transitioning laterally through even 4,000 fpm gust cores while near it's maximum altitude then it only confirms my previous suspision as to your experience.

Personal experiences? Sure. I learned to fly and spent the first almost 20 years of my career operatiing near and through what's considered the worst severe weather area on the planet, the mid-continental U.S. That experience includes 2 spring/summer season of Weather Modification, primarily hail supression where we didn't even take off to play chicken with them unless the CBs were at least Level 5s.

Experimental studies? As an offshoot of this program, we also (in the early/mid 80s, contracted by the governement) also had the displeasure of doing some of the early airborne-gathered data flights in the infancy of microburst reasearch by flying specially sensor-equipped aircraft for the explicit purpose of finding out what was going on inside a convective storm in order to correlate it with what ground and airborne-based radar sees. Microburst hunting, if you will. I will tell you this; for that program we did NOT enter those Level 5 or higher cells, nor did we enter ANY cells (or transition directly above developing cells) while at high altitude near the upper edge of our envelope. There's a world of difference encountering such forces at mid and lower altitudes (at the least extremely uncomfortable to quite possibly perilous) compared to high altitude (always an extremely perilous seat-pincher).

There's also a reason the CB penetration flights used to gather data on the probablilities of encountering differing degrees of light-to-extreme turbulence and hail diameters within CBs when they were working to devise the descriptive sytem of Levels based on reflectivity we still use today were accomplished in aircraft like F-106s.

Nothing has changed in that regard over the last 40 years in civil aviation no matter how efficient aircraft have become. They aren't designed for it. I've certainly flown with some nowadays, however, that don't know how the contours they see on their airborne wx radar correlate to CB levels, or worse, what the dbz levels of reflectivity are actually describing as it concerns the pilot; the varying degrees of probability of encountering low/light upwards to high/extreme turbulence, and low/small diameter to high/large diameter hail. BUT, as any pilot who's operated x-band radar knows, there are some prounounced limitations to getting the full picture.

Back then in the 80's maybe the accident lessons they had learned when transitioning to jets in the 60's and the unforgiving nature of high-altitude flying were still recent enough to drum into us and people took heed. Everything in my flying experience after that confirmed what I'd been taught, and my experience isn't limited to simply tooling along in level flight, on A/P, twisting a heading bug now and then to half-bank around the occasional cell. It's no "Hollywood" fantasy to know that convective weather and high altitude flying don't mix. From what I'm reading here though, I'm beginning to believe that a lot of those lessons have been forgotten, or downplayed over time.

Tim Vasquez has done an exceedingly great bit of research, but no matter how great your pictures or theories are, they are too macro and dependent on reflectivity levels and satellite imaging to truly see the full picture of the micro-level (meaning laterally small), severe dynamics contained in CB cells that can wreak havoc on an aircraft. When I was younger and braver, I helped collect data on just that in search of microbursts and their nature and as an offshoot CBs in gereral, directly experiencing how CBs can affect an aircraft in flight (with various air data recorders running for delivery to the much smarter folks than we)..not simply postulated what might happen based on sattelite imagery.

funfly

24th Jun 2009, 20:41

Captain Kirk are you really Ernest Gann?

Its very possible that the scenario encountered in this case could well have been outside of the ability of any pilot - however experienced. Therefore contributions highlighting the inexperience of fellow officers, while fascinating, are perhaps not relevent to this thread at this point in time.

Green-dot

24th Jun 2009, 20:50

Quote:
DJ77 quote..

AMF

Nice scenario ... for Hollywood.

AMF quote . . .

If you think that's a "Hollywood" scenario, then it tells me you're seriously lacking in knowledge when it comes to high altitude aerodynamics and experience with regards to hand-flying jet aircraft near the upper edge of it's envelope and the danger that lies just outside it, as well as obviously not very familiar with operating in close proximity powerful CBs on a routine basis.

To quote D.P. Davies' book "Handling The Big Jets" Third Edition:

The caption on plate 12, Flight at high altitude, opposite to page 109 describes it very well in a few words . . .

"It is difficult to express in a photograph the almost etheral quality of flight at very high altitudes-( . . . . .). In this picture, however, the photographer has managed to capture something of the atmosphere found at 35,000 feet. On a more practical level one should bear in mind the effect of this rarified atmosphere, which is to reduce aerodynamic damping. Because of this the pilot must be gentle with the aeroplane when manoeuvring."

The image on plate 12 illustrates relatively normal, daytime weather conditions at 35,000 feet, serene circumstances compared to what the AF447 crew may have encountered that night, possibly hand-flying a crippled airplane in rough air at high altitude.

G-d

Rananim

24th Jun 2009, 20:56

Declining pilot skills is an issue but by discussing it here we infer it was applicable to 447.We cant know that.
Lemurian made an assertion that the pilot can override the Flight Control Computer commands if the pilot feels that those commands are based on corrupted sensory data.How is this achieved?Can he break the chain only at the source(de-select ADR/IR) or can he intervene at the control level(de-select PRIM #)?Is there a recognized procedure or is it astronauts-only?How much lateral-thinking and system knowledge would be required in the diagnosis and corrective action?

mm43

24th Jun 2009, 22:13

Does anyone know the debris recovery number for the v/s per the data released by BEA on June 17?

Or, does anyone know the actual lat/long the v/s was recovered in?

mm

tquehl

24th Jun 2009, 22:28

Testpanel,

So, you are the preiminitent expert on pilot training, pilot evaluation in checking events and you wonder where the industry is going? I have been an evaluator in US 14 CFR 121 operations since 1992, including examiner for ATP/ATPL and instrument ratings in heavy jet airplanes.

In my humble opinion AF would never crew the flight deck with other than fully qualifed pilots for the position they served in. This is in accordance with required training. At least two, if not all were fully type rated and current on the airplane. The differention between Captain and First Officer is blured in the general public. A Captain is nothing more or less than a highly qualifed and experienced pilot designated as Pilot in Command in US FAA language. He is in absolute control, but he can designate. Very similar to when I go take a piss inflight and announce "Captain is off the bridge, FO has the Con" This is just for fun

FOs upgrade to Captain hourly on a world clock. Does this make them less competant as a PIC? I highly doubt this. I truly understand the search for knowledge on this forum, but some of the participants on this forum require me to just ignore, stand back and hope the true aviators set up a restricted message string.

Over

EGMA

24th Jun 2009, 22:29

There are three main reasons for a/c accidents:

(1) The pilot: Prime suspect, if only for the reason that he/she was the last to touch the a/c.

(2) Mechanical failure: Increasingly rare these days thanks to better design and testing of materials.

(3) Systems failures: Unfortunately creeping up the league table.

I admit I am not a jet jockey, but I have found myself in turbulent air in IMC. Before the a/p tripped I would take control (it was a crude a/p system), the reason; not many recover from unusual attitudes in actual turbulence, much better to take control of a stable aircraft and fly attitude/power.

With advanced systems, the a/p can probably fly the aircraft better than the crew, certainly more economically. When things start to go south, however, the system compensates with its built in redundancy (therein lies the danger). When it finally gives up, it hands over a, probably, uncontrollable aircraft to an inexperienced crew. I do not mean to be derogatory with the term inexperienced, my good buddy is a TC on 777s and I have nothing but admiration for his skills; but I would not class myself an experienced aviator if I switched in the a/p 12 secs after take off and off after landing.

Remember that when you do your sim/flight training you're geared up ready for what is about to come your way; much different to being in the cruise at FL350 on a dark night in the middle of nowhere.

Training has got to start including, recovery after major systems failure or better still recognizing the onset of a systems failure and stopping it becoming another AF.

I'm not optimistic that that can be achieved, humans are not good at monitoring computers; much better the other way around.

warmkiter

24th Jun 2009, 22:47

tquehl: thanks

if you check the flightexperience of the FO its unlikely he was a relief pilot, so all 3 were qualified..

good night and good luck

PJ2

25th Jun 2009, 00:57

Captain Kirk;

Your post shows both wisdom and experience - there are a number of us here who could have, and who indeed have, posted the same commentary on the industry.

Captain Sullenberger's presentation before Congress in February of this year was an excellent summary of these current, and disturbing, factors in our profession and a good summary of a number of posts here in the last few pages. Well done, sir.

PJ2
(Retired A330/340 captain)

woodja51

25th Jun 2009, 02:19

Try searching RAES - Home (http://www.aerosociety.com) and email the contact address and ask them to send it to you...

if no luck I will scan and reproduce it.

He is a FRAes and member of the Society's Flight Operations group ( hence the section is titled out of the F... O.. G.

That should help a bit.

W

Flyinheavy

25th Jun 2009, 03:52

Some of the postings here suggest that todays pilots are less proficient than they used to be. I would belive you should avoid generalizations like this. Looking at some accident reports of 1970 till 1990 you would find a lot of fuel to sustain your fire.

You might very well find that pilots training needs to be revised. I remember the quotation "...everybody can fly it, even the woman cleaning my office". He was talking of A330 and everybody in aviation should know to whom I am referring.

Somehow, talking of my oppinion, this philosophy made its way into the Cies in the quest to reducing costs wherever possible. I have no idea, if handflying the a/c at optimum FL under "Alternate Law" is part of Sim-training at AF, much less so with partial panel.

Consequently I would presume, even IF the pilots would be found 'responsible' for the loss of control, they would not have had a real chance without the proper training.

Remember, You do the drill in the Sim, so that you already have the proper answer ready for most of the abnormals that could happen inflight. If it was this what happened. Some interresting documents seemingly by AB/AF dealing with Unreliable IAS as of last year, at this site:

http://forfaiture.freeservers.com./

If true, why didn't they change the pitots earlier, we are talking now of two years of related problems and more than 30 cases.......

For the Top Guns here I have about 7k Landings, about 14 Autolandings (some Trng, some CAT3), the rest by hand, of course.

Awaiting the heat........:}

Flyinheavy

25th Jun 2009, 03:57

According Crash-Aerien, French pilot's Forum, the body of the Captain has been among those already retrieved. No further details given.......

PJ2

25th Jun 2009, 04:05

Flyinheavy;
Awaiting the heat........
No heat from me or many here - I agree with you. - it's training, training, training, all the way down and robust check rides that go back to high standards and being brought along by instructors who know the airplane inside and out.

When introduced, the 320 then 330/340 series required a new understanding of how flight controls and automation worked - the airplane is obscure and confusing only if a student was offered barebones groundschool and eight simulator sessions before flying the airplane under supervision.

For the vast majority of new candidates being hired, there is nothing "wrong" with today's young pilots that an appropriate level of training and experience gained under supervision can't address. "Success" has perhaps curiously been flight safety's biggest enemy, the temptation being to "fine-tune" expensive programs and standards on the back of a superb historical record, (forgetting how that record was achieved).

Flyinheavy

25th Jun 2009, 04:16

@PJ2

When introduced, the 320 then 330/340 series required a new understanding of how flight controls and automation worked - the airplane is obscure and confusing only if a student was offered barebones groundschool and eight simulator sessions before flying the airplane under supervision.

That's exactley what I mean, Automation stands for a lot of comfort, but when it quits, You're in front of a somtimes very complex situation and reduced training, for sure is the wrong answer.

The machine-human interface is not realy the best, I see that from the humans perspective.

My regards.

Finn47

25th Jun 2009, 04:28

As the pingers have a limited duration and it generally takes time to get the kit to detect / recover them to the scene, would it not be sensible to defer their start for a week or so?Since the beacon only weighs 200 grams including the lithium battery, I say double or triple the battery size instead?

swish266

25th Jun 2009, 05:09

I like that finally this thread is deviating away from speculation on salvage and systems faults...
The way I see it the only major cost cutting airlines can achieve in the foreseeable future is from crew cost and training cost.
Look - a drone can stay airborne for almost 48h depending on mission profile (that normally is much more complicated than flying A to B) and the guy/guys who fly it can get up, go to canteen, take a crap, take a siesta or even call the boss if things start getting out of hand... Isn't it beautiful?!
If in 10 years time the SLF is told they can fly for a third of the price of what they are paying now but in a robot driven a/c with A specialist (called PILOT) who is on board only for the never occurring need to do a hard reset of some equipment?!
Of course above para is a bit in line with H.G. Wells.
But... Are we sure?
Boeing and Airbus keep telling everybody that the price tag goes up because they are selling safer and better a/c that can be flown by CPL holders, albeit for the time being only from the RHS... Soon (I hear rumors) OPC/LPC might be done only once a year, but crew might have to be send to the sim for extra training... Who in their right mind will waste extra money on extra sim?! Once regulators give up the fight, recurrent training will be halved and this is not a H.G. Wells scenario.
To come back to experience levels of the Playstation Generation. The only way I see it is MFF. Put pressure on the young ones, so the keener ones make it faster up the ladder. Not on the Captain, that frequently has to put up with the unbelievable pressure of combining inexperienced crew with bad SOPs, commercial issues etc... Even more so if he wants to give something for free to the young guys!
I also heard a rumor that on this particular flight, AF447, the Captain might have come under pressure to depart on time with the usual "BITE test ok" bulshiv due to the presence of some big shots (God bless their souls) up front in biz class...
So I am asking myself once again why and how did they got themselves in the kind of bad wx that all of us normally avoid by 20 nm at least...
:confused:
:confused:
:confused:

Pontius Navigator

25th Jun 2009, 05:48

Back to the FDR/CVRs. As the pingers have a limited duration and it generally takes time to get the kit to detect / recover them to the scene, would it not be sensible to defer their start for a week or so?

That would be an added technical complication although it does have merit. We used to have PLB with a battery life of about 12 hours IIRC. We were taught to anticipate the time for SAR to reach the area.

There will certainly be a re-evaluation of FDR etc. Will they be ejectable? Is their purpose to mark the crash site as well as record flight conditions?

Maybe there should be a 3rd simple acoustic crash locator beacon.

augustusjeremy

25th Jun 2009, 06:33

a) 341115 - PROBE-PITOT 1+2/2+3/1+3
279334 - FCPC2(2CE2)/WRG: ADIRU1 BUS ADR1-2 TO FCPC2

OR

B) 279334 - FCPC2(2CE2)/WRG: ADIRU1 BUS ADR1-2 TO FCPC2
341115 - PROBE-PITOT 1+2/2+3/1+3

?????

ACLS65

25th Jun 2009, 06:45

"Air France 447 Search Effort: Phase II Fact Sheet
June 24, 2009
C & C Technologies, Inc. (C & C) has received inquiries regarding our discussions with the French BEA on the second phase of the AF447 search effort.

The following information may help minimize communication errors:

1) Pinger Life: Dukane, the AF447 pinger manufacturer, has confirmed that the pingers may only last a day or so longer than the specified thirty days. Unlike regular flashlight batteries that fade out slowly, the battery technology used in the pingers will hold its voltage for the thirty days, and then quickly collapse along with the transmitted signal.

2) Contact by BEA: The French BEA has contacted C & C by phone and e-mail regarding use of C & C's 4,500 meter (15,000 feet) rated autonomous underwater vehicle (AUV) to perform a sonar search for the flight recorders. C & C has two 250 foot (76 meter) ships near the crash area equipped with state-of-theart AUV systems. However, the AUVs on those vessels are only rated for 3,000 meters (10,000 feet), and the wreck area approaches 4,500 meters. If the pingers are not found by the end of June, French authorities may ask C & C to send its 4,500 meter rated AUV to Brazil to search the mountainous underwater terrain.

3) Comments Regarding BEA's Actions: While the first phase of the search for the flight recorders continues, the BEA is making contingency plans for a second phase. Tapping C & C's world-renowned deepwater AUV search capability indicates the French authorities' commitment to locate the recorders and solve the mystery. Given the complexity of the situation, the BEA is making all the right moves.

4) AUV Description: Like the unmanned drone aircraft used by the military, AUVs are unmanned, untethered, computer controlled underwater vehicles. C & C's 4,500 meter rated vehicle is capable of searching large areas while flying at a constant height off the ocean bottom at four knots for two days at a time before returning to the surface to refuel. ..."

Lafayette Company Assists in AirFrance Efforts (http://www.katc.com/Global/story.asp?S=10590507)

BOAC

25th Jun 2009, 07:46

So. Do you believe the rumour or are you posting it here to see if others do?- does this mean that someone (Swish266??) has information on the a/c tech state at dispatch? Please share it, Swish.

DJ77

25th Jun 2009, 08:54

- It is not about CBs.
- Even non fliers know that flying into CBs is dangerous.

Declining pilot skills is an issue but by discussing it here we infer it was applicable to 447

No more arguments from me. Just hope that readers understand how the above quote relates to post #2273.

etrang

25th Jun 2009, 09:31

Declining pilot skills is an issue but by discussing it here we infer it was applicable to 447

Do you mean 'we imply it was applicable to 447?

funfly

25th Jun 2009, 09:33

Can I suggest that most commercial pilots of the 'new' school will never have the opportunity to experience difficult situations in real flight because the aircraft sytems won't allow them to get into this position in the first place! You cannot blame them for not having this experience.
How, I ask, do you propose that the newer generation gain this flight experience apart from in a simm - let them do their first 1000 hours in a DC2?

free at last

25th Jun 2009, 10:06

I agree, hand's on is lacking. High altitude Radar knowledge, needs to be improved, as the new generation aircraft are flying higher, with less low and high speed stall margins. Seen all of it many times in the last 40 some years.:)

SaturnV

25th Jun 2009, 11:29

Flyinheavy,
AP PARIS – Air France says the bodies of the chief pilot of Flight 447 and a flight attendant have been retrieved from the Atlantic.

The airline says in on its Web site that the two are among those identified in the international search operation for remains of the 228 victims and wreckage of the May 31 crash. The airline hasn't identified crew members by name, but a pilots' union named the captain as Marc Dubois.

wings1011

25th Jun 2009, 11:31

sitting in the terminal on my way home and watching the news and they say that the captain and one steward have been found and identified. Information also backed up from airfrance they say.
Hopefully the BB will be found soon to clearify who were where when it happened/

Regrds

Wings1011

Gringobr

25th Jun 2009, 11:32

Reliable local news here in Brazil says the pilots body and that of another crew member have been identified..Pilot, not co-pilot etc... but do not know if other crew member was a pilot or cabin crew
Seems to me, as a humble PPL, that most of the debris, seat, bodies etc have all come from the front of the aircraft

BarbiesBoyfriend

25th Jun 2009, 12:13

If the Captains body has been found then there is plainly an implication, but no more than that, that he was not at the controls.

FE Hoppy

25th Jun 2009, 12:23

Gringobr- the Fin!!

BB don't see that at all. Why do you suggest that?

Squawk_ident

25th Jun 2009, 12:33

"Communiqué de presse diffusé le 25 juin 2009 : Dans le cadre de la publication d’un premier rapport factuel sur l’accident survenu le 1er juin 2009 à l’A330-200, immatriculé F-GZCP, le BEA tiendra un point presse dans ses locaux au Bourget le jeudi 2 juillet de 15 h à 17 h. Les journalistes qui souhaitent y assister sont priés de confirmer leur présence auprès de Martine Del Bono."

"Press release published on June 25, 2009: Within the framework of the publication of a first factual report on the accident which has occurred on June 1, 2009 to the A330-200 registered F-GZCP, the BEA will hold a press point in its office in Le Bourget on Thursday July 2 from 15:00 to 17:00.
Journalists who wish to attend are requested to confirm their presence at Martine Del Bono".

Bureau d'Enquêtes et d'Analyses (http://www.bea.aero/fr/enquetes/vol.af.447/com25juin2009.php)

Media are now announcing that the first report will be published the 30th of June, next Tuedsay

ekw

25th Jun 2009, 13:29

It's a fair working assumption that the bodies which have been found so far were at some point thrown clear. This would have had a far better chance of happening if they were not strapped in. If the captain was in the cabin when the event happened he may have tried to get back to the flight deck, but got pinned down by heavy g's. This would also account for him being found with a steward and not another pilot. Typically, the tube breaks just forward of the wing spar when bent enough - that would be the area where the cabin crew rest bunks are located.

If the assumption about bodies being thrown clear is correct, then more than 50 people were not strapped in, or were out of their seats - 25% of the loading - a fairly average number mid-flight. This would also point to a sudden event and not a gradual deterioration. Again, the sudden g's would have prevented any return to seats.

The SATCOM/ACARS could have continued functioning for a few minutes after the aircraft had already stopped flying, giving the potentially false impression that pilots still had some control.

It is very tempting to continue speculating - in 2000 posts somebody has probably got it right - but a line needs to be drawn between trying to interpret what data we have, and just thowing out blind theories.

wileydog3

25th Jun 2009, 13:36

Has anyone else come across this post? Its reportedly a Delta (NW) A330.
Does anyone know about its validity?

Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr. flight, we experienced the same problems Air France had while flying thru bad weather. I have a link to the failures that occurred on AF 447. My list is almost the same. http://www.eurocockpit.com/images/acars447.php

The problem I suspect is the pitot tubes ice over and you loose your airspeed indication along with the auto pilot, auto throttles and rudder limit protection. The rudder limit protection keeps you from over stressing the rudder at high speed.

Synopsis;
Tuesday 23, 2009 10am en-route HKG to NRT. Entering Nara Japan airspace.

FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get liquid water at these temps). We did.

As we were following other aircraft along our route. We approached a large area of rain below us. Tilting the weather radar down we could see the heavy rain below, displayed in red. At our altitude the radar indicated green or light precipitation, most likely ice crystals we thought.

Entering the cloud tops we experienced just light to moderate turbulence. (The winds were around 30kts at altitude.) After about 15 sec. we encountered moderate rain. We thought it odd to have rain streaming up the windshield at this altitude and the sound of the plane getting pelted like an aluminum garage door. It got very warm and humid in the cockpit all of a sudden. Five seconds later the Captains, First Officers, and standby airspeed indicators rolled back to 60kts. The auto pilot and auto throttles disengaged. The Master Warning and Master Caution flashed, and the sounds of chirps and clicks letting us know these things were happening.
Jerry S, the Capt. hand flew the plane on the shortest vector out of the rain. The airspeed indicators briefly came back but failed again. The failure lasted for THREE minutes. We flew the recommended 83%N1 power setting. When the airspeed indicators came back. we were within 5 knots of our desired speed. Everything returned to normal except for the computer logic controlling the plane. (We were in alternate law for the rest of the flight.)

We had good conditions for the failure; daylight, we were rested, relatively small area, and light turbulence. I think it could have been much worse. Jerry did a great job flying and staying cool. We did our procedures called dispatch and maintenance on the SAT COM and landed in Narita. That's it.

Dysag

25th Jun 2009, 13:40

Cabin crew bunks are located in the LDMCR which is placed just AFT of the wing box, not forward as you claim.

4PW's

25th Jun 2009, 13:43

I'm here tonight as I've heard about the Captain's body. But there's scant info, as expected. Instead, we have this Delta nonsense. You asked, so here's my oar. It's bollox. "The temperature on the flight deck became warm..." as it does, of course. Was that because of a failure of the packs, or the airspeed? Keep it real.

ekw

25th Jun 2009, 14:01

Dysag - yes you are right. LD-MCR - just aft of the wing in the rear cargo compartment. Actually I only said that there was a tendency for the fuselage to break forward of the wing in various crash scenarios. The inference was that anything either side of the break point would spill out.

wileydog3

25th Jun 2009, 14:03

TTCSE, no flight data or time stamp other than day.

The web says Delta does Narita Atlanta, New York and Salt Lake. ..

(duh)

I should have read closer. The flt was Hong Kong to Narita. And the initial report says the crew contacted dispatch.

I searched the FAA incident and FAA irregularity report web sites. NOTHING.

The SSK

25th Jun 2009, 14:15

wileydog3: Yes, I've seen that e-mail (including the name of the sender) forwarded by a retired Captain who flew with him out of NW's Tokyo base.

The incident happened on Tuesday

The sooner it's in teh mainstream of the accident investigation the better, I think.

wes_wall

25th Jun 2009, 14:42

Air France says the bodies of the chief pilot of Flight 447 and a flight attendant have been retrieved from the Atlantic.

Not to suggest anything, but recall, part of the crew rest module was recovered.

ACLS65

25th Jun 2009, 14:50

Regarding Delta (NW) A330

The problem I suspect is the pitot tubes ice over and you loose your airspeed indication along with the auto pilot, auto throttles and rudder limit protection. The rudder limit protection keeps you from over stressing the rudder at high speed. It sounds like this oversimplifys what may happen in terms of the rudder limiting.

Per the A330 FCOM Flight Controls Description:

"Rudder and pedal deflection is limited as a function of the speed. Each limiter channel is controlled and monitored by its associated SEC. In case of double SEC failure, the max rudder deflection remains at the value reached before failure ; then, a max deflection is available when the slats are extended."

SmartCockpit - Airline training guides, Aviation, Operations, Safety (http://www.smartcockpit.com/pdf/plane/airbus/A330/systems/0010/)

takata

25th Jun 2009, 15:01

wes_wall:
Not to suggest anything, but recall, part of the crew rest module was recovered.The crew rest module is for FA only, not to mention its damage state.

piedmont1984

25th Jun 2009, 15:21

Red coloration on the radar indicates rain intensity. Heavy rain alone does not constitute a hazard to be avoided at all costs. The same applies to heavy(strong) landing/takeoff winds, heavy snow or ice, heavy weight, heavy anything, without considering other factors.

Experience and training come into play. If the red is accompanied by steep contouring or gradient, known CB activity, known tops which cannot be overflown by several thousand feet, known or depicted significant turbulence, lightning, stage of development other than dissipating and a strong sense of smell - as in this doesn't smell right - then by all means go around it, fuel permitting. Even a partial list would suffice in order to turn around or go around.

But if you have never flown through or over heavy rain, then I would be interested in knowing what your experience level is and where in the world have you operated.

Unless I have misunderstood your post, in which case, my apologies.

Piedmont1984

Jetdriver

25th Jun 2009, 15:23

To save a few of you, and us, the trouble of having to delete dozens more of these gullible posts you might like to watch this promotional clip.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/VdD6vza8MjE&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/VdD6vza8MjE&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

If the penny has now dropped, and you are not busy providing details of your bank account to the supposed family of a deposed West African General, perhaps you could restrict comment to the subject of this thread.

lomapaseo

25th Jun 2009, 15:48

Normally I don't post news or rumors preferring intstead to simply read what others think is important. But just to place a counterpoint alongside the rumor above about the Delta/NW A330 storm encounter

[quote]EASA Plans No Immediate Action On A330 Pitot Tubes

The European Aviation Safety Agency has decided, for now, to hold off on issuing an air worthiness directive concerning Thales-made pitot tubes on A330/A340s.

EASA said, “We are not planning any action at this stage pending the investigation” into the crash of Air France Flight 447.

The pitot tubes have come under fire in the wake of the crash of AF447 because the mishap aircraft, an A330-200, broadcast maintenance messages just before all contact was lost indicating inconsistent speed information and potential problems with the pitot tube. Air France and other airlines had previously encountered problems with the pitot tubes and Thales had developed an upgrade, but an equipment change was not mandated by safety officials.

Even before the crash, Air France had decided to upgrade its pitot tubes, but the mishap aircraft was still flying with the old standard. The airline has since upgraded all the probes, in part under pressure from its pilots.

Air France and aviation safety officials insist there is no data available at this point to suggest a problem with the pitot tubes was in fact linked to the crash. Industry officials point out that even with pitot tubes malfunctioning, pilots should still be able to fly the aircraft.

Aviation Week's AviationWeek.com (http://www.aviationweek.com).

Razoray

25th Jun 2009, 15:58

Why does the EASA drag it's feet?

Apparently all the Pilots of Air France disagree with them!

:ugh:

Xeque

25th Jun 2009, 16:14

Everything returned to normal except for the computer logic controlling the plane. (We were in alternate law for the rest of the flight.)
Is this really acceptable to you professionals?

wileydog3

25th Jun 2009, 17:54

Odd thing is there is NOTHING on the FAA incident site or the service difficulty reporting site. Nothing on the sharing site. Nothing anywhere. ???

wileydog3

25th Jun 2009, 18:00

Xeque Is this really acceptable to you professionals?

...that the report is being floated or that the rest of the flight was in ALTERNATE LAW? Not clear.

My point is just to find out if this is valid and if so, why, two days after the incident, is it completely invisible as far as the governing agencies websites? Or anywhere else for that matter.

Remember too this is yet another incident in the Pacific with unusual precip. We had other incidents with flame outs due to super-cooled water droplets (large and small) and this one mentions RAIN at cruise altitude (FL380?).

carholme

25th Jun 2009, 18:09

Wileydog3;

It has also shown up on AvCanada as a forwarded email, also without any markers to prove credibility. Google shows nothing about the captain and no other reporting site has yet has verified. Seems strange to post the airline name and yet no other verifiable information.

carholme

PJ2

25th Jun 2009, 18:09

The unofficial Delta crew report must be verified. Nothing can move forward without this first step.
If the incident happened, one hopes that Delta does a FOQA program on the 330; if so, perhaps the QAR can be downloaded, (far more data and greater sampling rates for some parameters). One hopes too that given the incident and current circumstances they have already pulled the recorders including the CVR at NRT and shipped them to Washington.

Hopefully more information will be available on this throughout the day, with the usual caution that hindsight is 20/20. We know where this "points" but that is all we know as to possible cause(s).

augustusjeremy;
egg and chicken
a) 341115 - PROBE-PITOT 1+2/2+3/1+3
279334 - FCPC2(2CE2)/WRG: ADIRU1 BUS ADR1-2 TO FCPC2

OR

B) 279334 - FCPC2(2CE2)/WRG: ADIRU1 BUS ADR1-2 TO FCPC2
341115 - PROBE-PITOT 1+2/2+3/1+3

?????

These are recorded early in the entire sequence, (0210Z). The latter fault have associated Maintenance Status messages (ATA279000)

As per a number of experts' comments, the timing of the ACARS messages apparently can't be fully sorted out with 100% confidence not only because of the way the ACARS interfaces with the CMC, (Central Maintenance Computer) but becauses of the timings of individual system BITE processes which may complete and where such exists, latch a fault and then report. I personally think it is significant that the Pitot probes fault message comes before the first ADIRU messages but have nothing to substantiate that opinion. Perhaps those with special systems knowledge will be able to sort out which message came first by knowing that another fault wouldnt' have occurred without the first fault, etc etc.

A quick examination of the new ACARS PFR (Primary Fault Report?) list shows a few new details which had not been available on the first list made available:

A windshear Detect Fault, (My AMM shows “22-62-020” as the W/S DET FAULT)
The ISIS “Speed or Mach function”
Reference to ATA 279334 – FCPC2 and the explanation: WRG:ADIRU1 BUS ADR1-2 to FCPC2 – does this mean that FCPC2 took over inputs to ADR1 & 2?
Confirmation of Hard fault ATA 341115 PROBE PITOT 1+2 / 2+3 / 1+3
Clarification of the warning flag on the Capt PFD – Flight Director flag
Clarification of the warning flag on the F/O PFD – Speed Limit
Clarification of the PFD Flags at 0211 as “FPV”, flight path vector warning flags – this is an interesting fault
The “INTM” (Intermittent) AFS Class 1 Fault ATA 228334 – FMGEC1 (1CA1) BITE Detection is “CPC receives no data from FMGEC1”
My sole point in asking this is, if a rapidly devolving FMGES (Flight Management Guidance and Envelope System - all input devices, associated computers and crew interface units) are sending BITE results, by what method are they sorted for input into the CMC (and then sent to the ACARS)?
Perhaps the question is unimportant but the intent is clear enough; I just don't know enough to judge whether the order of ACARS messages we see is a result of this kind of critical process or not.
PJ2

quaeler

25th Jun 2009, 18:18

Wileydog3:

Usually JACDEC is pretty good in keeping up with even minor in-flight incidents; current recent events, which don't mention this event (?yet?), can be viewed here: JACDEC - Current News (http://www.jacdec.de/news/news.htm)

(If someone is inclined actuarial-wise and bored, i'd love to know whether there are more 330 incidents reported recently or that i'm just more sensitive to the aircraft).

PJ2

25th Jun 2009, 19:03

augustusjeremy;

Yes, I think the TSM would help. Again, hopefully investigators are now far ahead of anyone here in terms of thinking/assessing/postulating/investigating. I'm sure in a few cases this site has provided some insight for the process but this is what they do and there are people who know the nuts-and-bolts of the 330 far better.

Re,switched cables
Not sure what you mean by this but if you are referring to reversed cannon plugs for warning systems, yes, I know that has occurred, although I don't know where - manufacturing or regular heavy maintenance. It is not appropriate to provide details here but it would have resulted in an emergency if I'd followed the ECAM without thinking first.

reallynoidea

25th Jun 2009, 19:18

ACLS65 Quote
Per the A330 FCOM Flight Controls Description:

"Rudder and pedal deflection is limited as a function of the speed. Each limiter channel is controlled and monitored by its associated SEC. In case of double SEC failure, the max rudder deflection remains at the value reached before failure ; then, a max deflection is available when the slats are extended."

Apologies if this is silly - haven't seen it before and can't find an answer -
What would allowable rudder deflection be if, before the double failures, airspeed was 'indicated' to be very low. Would that allow full rudder following the SEC failures? Or is there logic that only allows min deflection once limiting is activated, until slats deployment?

Cheers

ACLS65

25th Jun 2009, 19:22

I had a doc that mentioned that there were software differences between the A330 and A340, I will find that again.

In looking I found this doc that is so far the most in depth discussion of Flight Control Systems I have run across. This doc discusses FCS from the beginning through today including the Airbus and Boeing systems.

http://media.wiley.com/product_data/excerpt/66/04700599/0470059966.pdf

AMF

25th Jun 2009, 19:38

DJ77
This thread is about AF447
- It is not about CBs.
- Even non fliers know that flying into CBs is dangerous.

Well since the major, dynamic threat to safety along AF447's route of flight that night was a large area of CBs, and that was also the area which the aircraft was transitioning through at FL350 when was lost, I'd say CBs, what they produce in terms of threatening a flight (turbulence, icing, hail, vertical gusts, effects on aerodynamics and equipement), and difficulties detecting what can be the more severe aspects of them with airborne radar at high altitude, is indeed pertinent as any other discussion about it. Cetainly as pertinent as bits of debris, schematic drawings, and ocean currents.

ACLS65

25th Jun 2009, 19:52

reallynoidea (http://www.pprune.org/members/198286-reallynoidea):
What would allowable rudder deflection be if, before the double failures, airspeed was 'indicated' to be very low. Would that allow full rudder following the SEC failures? Or is there logic that only allows min deflection once limiting is activated, until slats deployment?I don't have detailed enough information to answer this, but it is an idea that has been floated here. I (and probably others) also brought up the idea of working through things from the probes to the ACARS msgs vs. starting at the ACARS msgs and trying to work back to what could have caused them.

My question at that point was if you could reach out and slap a piece of tape over the pitot tubes what affect would this have on the instruments in terms of IAS, AOA, ALT, and any other inputs to the ADIRU's, and then how would the FCS react.

The bigger question being how the FCS system would handle what may have appeared to be a rather sudden change in these parameters. There are various protections for different conditions that could come into play if the FCS was convinced that condition existed. On top of that you have the possibility the faulty inputs cause the FCS to fail what could be good components.

Previous A330 (and possibly since) upsets tend to make this seem like a recoverable situation, but add the weather, darkness, and any other number of factors on top of this and you might have a situation that is simply to complex to handle in the available time.

golfyankeesierra

25th Jun 2009, 20:36

Which type of pitots do NW A330's have?
And if it's Thales, are they being upgraded?

GarageYears

25th Jun 2009, 20:38

Has anyone else come across this post? Its reportedly a Delta (NW) A330.
Does anyone know about its validity?Given the similarity apparently to AF447 this should be all over the news, but after searching everywhere, at least what I could in 2 hours, there is nothing to verify this - just a huge empty hole. Right now it looks suspicious. Very.

- GY

positive climb gear

25th Jun 2009, 20:52

One particular design flaw, I feel, on the Airbus series of aircraft is the fact that the throttles remain in a fixed position during flight. Your only reference for current power is the Engine/Warning Display and FMA. I have been in turbulence in an A320 where it was IMPOSSIBLE to read any of the screens in front of me...
The drill for unreliable speed is to fly pitch and power...difficult if you cannot read the instruments in front of you! With Airbus, currently you retard the throttles to their current power setting as displayed on the E/WD display. If we had throttles that moved, the first stab at a power setting would be the current one ie just disconnect the autothrust.
It would also make monitoring the aircraft a little easier- if you saw the throttles retard to idle in flight and yet you remained level, you would know (in steady state conditions at least) that if you let the situation develop you would likely encounter a stall. Similarly the reverse is true if you see the throttles move to MCT.
Perhaps it is time we, as pilots, are given back some of the intuitive information we require when HAL gives up the ghost.

Mike-Bracknell

25th Jun 2009, 21:01

Just a quick question (yes yes, there's an underlying theory)...

Where on an A330 are the radio antennae mounted?

The theory being that if they're mounted in the VS for height and lack of fuselage in the way, then the alternate law rudder movement theory and associated VS removal would account for why no radio messages post this incident.

Expanding on that thought: if the antenna (wherever it is) was removed from the radio for whatever reason for the crash, then that may explain the lack of radio messages. (e.g. if it's in a wing, and the wing falls off - voila - no radio).

(hey, aren't we due a bit of speculation about now?):ok:

24victor

25th Jun 2009, 21:11

Lost-in Saigon posted a diagram of the antenna locations in post #992. Only the powered HF antenna is located in the fin and there's no ACARS message to suggest it departed the aircraft prior to ACARS termination.

Rgds.

24V

wileydog3

25th Jun 2009, 21:28

I went to the FAA accident/incident data base and scanned for incidents/accidents from 01/01/2008 for a sampling. Basically nothing. 7 reports of which only two were 'substantial' and 4 of the 7 were ground events.

Aviation Accident Database Query (http://www.ntsb.gov/ntsb/query.asp) for the NSTB reports and it has 6 entries, all non-fatal.

Service Difficulty Report Query Page (http://av-info.faa.gov/sdrx/Query.aspx) for airbus A330* (for all 330 versions). 35 records. 1 24** JACDEC codes (electric) for a seat. 2 27** for Primary Flt Control Computer failing and being replaced in 2000. But in the 35 records NO 3030 which is pitot static system.

NONE and now this. ???

repariit

25th Jun 2009, 22:04

The version of the Delta/NWA email I received had both pilots' names on it. It would be a simple thing for it to be verified. I would leave it to the authorities instead of we anonymous posters.

Hyperveloce

25th Jun 2009, 22:09

Has it been confirmed that the AF 447 was fitted with the Backup Speed Scale & Altitude display (*) ?
Jeff
(*)http://www.smartcockpit.com/data/pdfs/flightops/flyingtechnique/Unreliable_Speed.pdf
http://aviationtroubleshooting.*************/2009/06/af447-unreliable-speed-by-joelle-barthe.html

Squawk_ident

25th Jun 2009, 22:20

************************************************************
NTSB ADVISORY

************************************************************
National Transportation Safety Board
Washington, DC 20594
June 25, 2009
************************************************************
NTSB INVESTIGATING TWO RECENT INCIDENTS INVOLVING
POSSIBLE A-330 SPEED AND ALTITUDE INDICATION ANOMALIES
************************************************************

The National Transportation Safety Board is investigating two recent incidents in which airspeed and altitude indications in the cockpits of Airbus A-330 aircraft may have malfunctioned.

The first incident occurred May 21, 2009, when TAM Airlines flight 8091 (Brazilian registration PT-MVB) flying from Miami, Florida to Sao Paulo, Brazil, experienced a loss of primary speed and altitude information while in cruise flight. Initial reports indicate that the flight crew noted an abrupt drop in indicated outside air temperature, followed by the loss of the Air Data Reference System and disconnections of the autopilot and autothrust, along with the loss of speed and altitude information. The flight crew used backup instruments and primary data was restored in about 5 minutes. The flight landed at Sao Paulo with no
further incident and there were no injuries and damage.

The Safety Board has become aware of another possibly similar incident that occurred on June 23 on a Northwest Airlines A-330 (registration unknown) flying between Hong Kong and Tokyo. The aircraft landed safely in Tokyo; no injuries or damage was reported. Data recorder information, Aircraft Condition Monitoring System messages, crew statements and weather information are being collected by NTSB investigators.

Further information on both incidents will be released when it becomes available.

###

NTSB Public Affairs
(202) 314-6100
Ted Lopatkiewicz
[email protected]

pianoforte

25th Jun 2009, 22:34

I got this e-mail too, but from a source that is highly suspect. All 3 speeds behaving the same way at the same time sounds odd, plus there is something about the way the message is written. I can find no corroboration of this event, anywhere.

ACLS65

25th Jun 2009, 22:36

The name Ted Lopatkiewicz is listed for NTSB contacts.

Resources for Journalists (http://www.ntsb.gov/Events/journalist/NTSB-PA-contacts.htm)

But I can't seem to find the release posted.

NTSB - Press Releases (http://www.ntsb.gov/Pressrel/pressrel.htm)

Razoray

25th Jun 2009, 22:39

A common thread of these incidents seems to be a drastic drop in outside air temperture.

Erractic and/or extreme weather patterns may be aiding to these malfunctions.

It is interesting that all of these incidents are grouped so close together.

24victor

25th Jun 2009, 22:46

Wiley
If you use A330% for the aircraft type you'll get 174 SDR entries. You can use that parameter with whatever code you select to find ADIRU or whatever reports. I would play with it but gotta go. Later maybe.
Rgds.
24V

Graybeard

25th Jun 2009, 23:02

More questionable, P51guy, is how you could design a static port to freeze up at flight levels. Prior to the above, I don't believe there was any report of false altitude. A frozen static is more dangerous than frozen pitot.

The prior reports of events discussed a temperature rise, not a fall, as above. An iced TAT sensor will logically show temperature increase, as it becomes insulated from outside air, and the ice next to the sensor is warmed.

I am suspicious of both the DeltaNW event, and the NTSB release.

GB

unclemohammed

25th Jun 2009, 23:13

I have noticed that the post, posted by squawk_ident has got the email address incorrect, for Ted Lopatkiewicz. If you click the link 'Resource for Journalists' from ACLS65's post then click on Ted's name the email address comes up as:

LOPATKT @ ntsb.gov

not lopatt @ ntsb.gov which comes up at the bottom of squawk_ident's post....(please pardon the spaces in between the posted email address, it comes up as 'invalid hash' on my machine for some reason, security?)

Highly suspect in my opinion, unless someone can confirm the NTSB post, it is certainly not in the public domain.

Mo'

lomapaseo

25th Jun 2009, 23:16

JungleDan

lumpaseo,

Thanks for the Aviation's week link. Quite frankly, I find the whole pitot probe story utterly confusing! On the one hand, the posts I've read from a/c pilots seem to indicate that air speed data are critical to safe flight conditions. On the other hand, EASA seem to consider that pitot probes issues are no big deal, just routine work, really...

I just don't understand how pilots' and officials' positions can be that far apart, as if they were living in two completely separate worlds? Seems to me that pitot probe icing is either hazardous or it isn't...

Agree!

The confusion stems from the typical myriad of expert opinions offered on the internet. The main reason that I posted that link was to illustrate that there are many facets to our (internet) collective lack of understanding. :)

One thing that you can be sure of, it will be sorted out by the investigators.

Every so often I do post a hint that we aren't going to understand some of these accidents without understanding the man and machine interface that played at the same time. There's no use speculating about this without many more facts to support the great amount of speculation

prayingmantis

25th Jun 2009, 23:20

I can confirm the NTSB post, as I also received the same NTSB press release to my email address (I subscribe to their feed). I noticed some formatting errors in the post but the text is verbatim from the release. I tired to post the same release but wasn't quite as quick on the draw :-)

-Chris

xcitation

25th Jun 2009, 23:23

The issue with the pitot in isolation would appear to be not so grave so you have the authorities issuing warnings. Loss of airspeed is anticipated in the QRH and training.
However I think in the case of Airbus equipment we have a compounding secondary issue of the flight computers not gracefully handling the loss/corruption of airspeed sensor data.
So the authorities looking at the pitot issue by itself only see part of the problem. Much as the 5 blind men feeling parts of the elephant and each coming to different conclusions. What is need is a higher level perspective of the issue that combines all of the parts of the problem.

At the end of the day I can't understand how one sensor (ok 3 redundant pitots) can take out something as critical as an entire flight system. It appears that there are too many dependencies in the software that causes the pitot failure to initiate a chain of software errors that are not handled. Instead the errors cascade to secondary software modules which go into failed state. Good electronic/software design seeks to minimize coupling and un-necessary dependencies. Error exceptions are handled gracefully and trapped.

kenhughes

25th Jun 2009, 23:24

Nothing at all on the NTSB website - but I found this piece in the Fresno Bee (so it must be true :})

NTSB probes 2 incidents involving Airbus A330s - National Politics - fresnobee.com (http://www.fresnobee.com/news/national-politics/story/1497917.html)

beamender99

25th Jun 2009, 23:33

More trustworthy reports?

NTSB probes 2 incidents involving Airbus A330s
By JOAN LOWY –WASHINGTON (AP)
Federal safety officials say they are investigating two reports of Airbus A330 planes experiencing airspeed and altitude malfunctions.
The aircraft are the same type as the Air France plane that crashed into the North Atlantic on May 31 after sending out low airspeed messages, killing all 228 aboard.
The National Transportation Safety Board said the first incident occurred May 21, when TAM Airlines Flight 8091 flying from Miami, to Sao Paulo, Brazil, experienced a loss of primary speed and altitude information.
The board's information on the second incident is more sketchy, but it involves a Northwest Airlines flight between Hong Kong and Tokyo on June 23. In both cases the planes landed safely.

Incident: Northwest A333 over East China Sea on Jun 23rd 2009, unreliable airspeed (http://avherald.com/h?article=41bb9740)
Incident: Northwest A333 over East China Sea on Jun 23rd 2009, unreliable airspeed
By Simon Hradecky, created Thursday, Jun 25th 2009 22:26Z, last updated Thursday, Jun 25th 2009 22:37Z
A Northwest Airlines Airbus A330-300, registration N805NW performing flight NW-8 from Hong Kong (China) to Tokyo Narita (Japan), was enroute overhead the East China Sea, when the crew noticed a sharp drop of the indicated outside temperature followed by the loss of the air data reference system, disconnection of autopilot and autothrust system along with the loss of speed and altitude information. The flight crew used the stand by systems and was able to restore the primary data. The airplane landed safely in Tokyo Narita.

The NTSB is investigating, the flight data recorders have been retrieved, the aircraft condition monitoring system messages, crew statements and weather information are being collected by NTSB investigators.

The NTSB reported, that a very similiar incident happened on May 19th to a TAM Airbus A330-200, see Incident: TAM A332 enroute on May 21st 2009, unreliable airspeed and altimeter (http://avherald.com/h?article=41bb988a&opt=0).

PJ2

25th Jun 2009, 23:35

GB;
I am suspicious of both the DeltaNW event, and the NTSB release.
Also, with reference to the A330 QRH "UNRELIABLE SPEED INDICATION/ADR CHECK PROCEDURE, for Cruise between FL200 and FL360, the N1 setting, (Trent installation) is 69.6%, pitch is 2.5deg; above FL360, N1 required is 77.2%, pitch, 3.0deg.

The comment in the informal "report" first posted states that the crew used "83%N1". The lower N1 referenced in my QRH may be due to engine installation but shouldn't otherwise vary. I believe Delta A330's have the CF installation however - don't the GE installations use EPR?

Also - not sure about the "Nara Japan" comment. There is "Naha" FIR but I don't recall any "Nara".

The fact that such a report hasn't officially surfaced, with comments, certainly makes it suspicious. It's two days old.

Agaricus bisporus

25th Jun 2009, 23:37

how you could design a static port to freeze up at flight levels.

I've been led to believe that previous incidents where similar symptons occurred (Air Caribies or something like that?) the problem was not the things freezing up, rather the thawed ice flowing back down the plumbing and causing varying and moving hydraulic blockages.

takata

25th Jun 2009, 23:56

As far as I know, Northwest was using Thales 'C16254AA' probes (the same as AF447) but as the press is not making its headlines: "NORTHWEST FAILED TO REPLACE THE PITOTS" (23 days after AF 447 crash) following AIRBUS directives bla bla bla..." like in Air France case... or maybe the new model C16254BA did freeze?... or it is another hoax.
:)
S~
Olivier

GarageYears

25th Jun 2009, 23:57

This still looks very suspicious to me - there are several formatting issues with the report (in other words this PR differs from all others in a few ways compared to all other NTSB PRs), and the fact this is dated 6/25/2009 and still not listed on the NTSB website does not make sense.

For now I'd regard this as suspicious. And just because a few local newspapers pick up on it does NOT make it official. Viral email fakes are easy to produce. Does anyone have the purported email - can you publish the full email header? This will almost certainly prove the source one way or another.

- GY

Willoz269

26th Jun 2009, 00:01

It is a problem for the Pitot manufacturers....Qantas did a lot of work on the pitot tubes of their 767 fleet after it was found that there were sheets of ice forming on the inside of the fuselage, around the rubber seal of the pitot tube. They installed a heater for the O ring to try to solve this problem before it becomes a serious issue. The Qantas fleet does not use the default Pitot tubes that come with the A330, they have their own supplier. Airbus does NOT build or produce Pitot tubes, they purchase them from another supplier as well.

wes_wall

26th Jun 2009, 00:06

The release from the NTSB is real. It was sent via Email to subscribers. FYI, two (2) emails were sent one behind the other. First,

NTSB ISSUES UPDATE ON INVESTIGATION INTO COLLISION OF TWO METRORAIL TRAINS IN WASHINGTON, D.C.

and second,

NTSB INVESTIGATING TWO RECENT INCIDENTS INVOLVING
POSSIBLE A-330 SPEED AND ALTITUDE INDICATION ANOMALIES

So, put it to rest. they are authentic.

And since you asked:

************************************************************

NTSB ADVISORY

************************************************************

National Transportation Safety Board

Washington, DC 20594

June 25, 2009

************************************************************

NTSB INVESTIGATING TWO RECENT INCIDENTS INVOLVING

POSSIBLE A-330 SPEED AND ALTITUDE INDICATION ANOMALIES

************************************************************

The National Transportation Safety Board is investigating

two recent incidents in which airspeed and altitude

indications in the cockpits of Airbus A-330 aircraft may

have malfunctioned.

The first incident occurred May 21, 2009, when TAM Airlines

flight 8091 (Brazilian registration PT-MVB) flying from

Miami, Florida to Sao Paulo, Brazil, experienced a loss of

primary speed and altitude information while in cruise

flight. Initial reports indicate that the flight crew noted

an abrupt drop in indicated outside air temperature,

followed by the loss of the Air Data Reference System and

disconnections of the autopilot and autothrust, along with

the loss of speed and altitude information. The flight crew

used backup instruments and primary data was restored in

about 5 minutes. The flight landed at Sao Paulo with no

further incident and there were no injuries and damage.

The Safety Board has become aware of another possibly

similar incident that occurred on June 23 on a Northwest

Airlines A-330 (registration unknown) flying between Hong

Kong and Tokyo. The aircraft landed safely in Tokyo; no

injuries or damage was reported. Data recorder information,

Aircraft Condition Monitoring System messages, crew

statements and weather information are being collected by

NTSB investigators.

Further information on both incidents will be released when

it becomes available.

###

NTSB Public Affairs

(202) 314-6100

Ted Lopatkiewicz

[email protected]

************************************************************

This message is delivered to you as a free service from the

National Transportation Safety Board.

You may unsubscribe at any time at

NTSB - Mailing Lists (http://www.ntsb.gov/registration/registration.htm)

An archive of press releases is available at

NTSB - Press Releases (http://www.ntsb.gov/pressrel/pressrel.htm)

Current job opportunities with the NTSB are listed at

NTSB - Vacancy Announcements (http://www.ntsb.gov/vacancies/listing.htm)

For questions/problems, contact [email protected]

EmBee

26th Jun 2009, 00:25

Agaricus bisporus quote - followed up by ttcsethe problem was not the things freezing up, rather the thawed ice flowing back down the plumbing and causing varying and moving hydraulic blockages.Try the following link and the authors 'third theory' re Qantas Airbus A330-303 in-flight upset (QF72).

The QANTAS Airbus A330 Inflight upsets (http://www.iasa-intl.com/folders/belfast/ADIRU_faults&Tolerances-2.htm)

Will Fraser

26th Jun 2009, 00:44

Pedant mode. "indications in the cockpit malfunctioned"

"there were no injuries and damage"

Indications don't malfunction, (not in English)

there were no injuries or damage is correct

If this is verbatim, it didn't appear originally in English, NTSB doesn't make those kinds of syntactic blunders.

Will

ITman

26th Jun 2009, 01:40

A Boeing with similar problems..?

http://www.pprune.org/rumours-news/379115-lot-boeing-767-severe-turbulence-unreliable-airspeed-june-19th.html

Airways Ed

26th Jun 2009, 02:06

"GarageYears said: Does anyone have the purported email - can you publish the full email header? This will almost certainly prove the source one way or another."

The original email purportedly came from a msn.com address; however, when that address is selected the yahoo mail login page comes up...

mickk

26th Jun 2009, 02:11

Another report that these things dont like storms.

ATE: 20.06.2009 LOCAL TIME:early morning LOCATION: Tel Aviv-Intl AP area (LLBG) COUNTRY: Israel AIRLINE: bmi British Midland TYPE: Airbus A330-243 REGISTRATION: G-WWBD C/N: 401 AGE: 8 y + 2 m OPERATION: ISP FLIGHT No.:BD 762 FROM: London-LHR TO: Tel Aviv VIA: - OCCUPANTS: PAX: - CREW: - FATALITIES: PAX: 0 CREW: 0 OTHER: 0 INJURIES: PAX: 10+ CREW: 0 OTHER: 0 DAMAGE TO AIRCRAFT: minor On approach to Ben Gurion Airport, the A330 was hit by lightning. The entire right wingtip appeared to have detached during the thurnderstorm encounter sincei t was found missing on arrival. Despite the damage, the pilots made an uneventful landing.

etrang

26th Jun 2009, 04:12

The alleged NTSB press release contains many grammatical and stylistic errors.

takata

26th Jun 2009, 05:05

Will Fraser:
If this is verbatim, it didn't appear originally in English, NTSB doesn't make those kinds of syntactic blunders.The press is jumping on it without providing a single additional detail from the NTSB. This stuff was not cross-checked by any (real) journalist.

Also:
- why only the A330 without the A340?
- nothing about the suspected pitot probe model;
- still nothing published in the NTSB press releases page where the other one is published: "NTSB Issues Update On Investigation Into Collision Of Two Metrorail Trains In Washington, D.C."
NTSB - Press Releases (http://www.ntsb.gov/Pressrel/pressrel.htm)

Someone with a genuine (older) NTSB e-mail archived should be able to compare the headers and tell us the truth. I don't think that the NTSB would use MSN for sending e-mails.

This is plain wrong and smell like another hoax. The previous NW Capitain's report looked strange also and circulated by e-mails (a friend who had it from a friend, e-mailed it to me...).

Dysag

26th Jun 2009, 05:23

If I sent an e-mail about the N-TSB, folks would spot the error. I don't believe the real NTSB would call the plane an A-330. They surely know how to use the correct model names.

takata

26th Jun 2009, 05:44

If I sent an e-mail about the N-TSB, folks would spot the error. I don't believe the real NTSB would call the plane an A-330. They surely know how to use the correct model names.
No... they don't:
Press Advisory (http://www.ntsb.gov/Pressrel/2009/090603a.html)
A-:D330

AMF

26th Jun 2009, 06:02

ITman quote,, A Boeing with similar problems..?

A LOT Polish Airlines Boeing 767-300, registration SP-LPA performing flight LO-2 from Chicago O'Hare,IL (USA) to Warsaw (Poland) with 206 passengers and 10 crew, was enroute at FL330 about 9nm eastsoutheast of North Bay,ON (Canada) about 70 minutes into the flight (Jun 19th 22:02L, Jun 20th 02:02Z), when the airplane encountered "severe turbulence at high speed" and started to deviate signficantly from assigned altitude. The crew reported later, that their airspeed had become unreliable and requested to divert to Toronto,ON (Canada). During descent towards Toronto the crew reported, that airspeed had returned to be normal and requested to hold to reduce weight. No ambulances were needed. While in the hold and descending, the crew was ordered to stop descent at 16000 feet, the crew was however unable to comply and reported, the airspeed problems had reoccured. The airplane proceeded directly for a safe landing on runway 23 73 minutes after the onset of problems and taxied to a gate.

At the time of the incident air traffic control reported continuous light chop (light turbulence) on all altitudes above FL300, later changed to severe turbulence at FL330 reported by a 763.

The Canadian TSB reported on Jun 22nd, that the airplane was enroute at FL330 near North Bay, when it experienced a sudden and uncommanded overspeed condition, stick shaker and illumination of the left and right hand engine electronic control (EEC) caution lights. The aircraft descended to FL280 before the situation was resolved. The airplane diverted to Toronto, where it landed without further incident. The TSB has dispatched investigators to the site.

Boeing, Airbus, Lockheed, Douglas, Gulfstream etc. etc..it doesn't matter who builds it. Every aircraft designed, with all equipment operating perfectly, will experience sudden air data and aerodynamic screwiness if running into bona fide severe turbulence, especially at high altitude. In this case, and uncommanded overspeed condition, a stick shaker (associated with an underspeed/high AOA) condition, and possible engine problems (EECs also use air data). If that aircraft had been at FL350 or FL370 (where it's aerodynamic margins were even smaller) and transited into the same level of turbulence, the situation would have been even dicier, especially if there is a sudden temperature change(s) (as there often is, affecting mach number and performance) associated with the area of shearing and/or vertical gusts. Sudden temp changes only compound the problem of airspeed control when trying to stay between narrow buffet margins.

The severe turbulence was unreported until that particular aircraft encountered it, and when it did there was no malfunction of systems at the time. The event, however, apparently caused one that recurred later, which is no suprise. There's no mention of icing, or malfunctioning/frozen pitot-static sources. But there doesn't need to be, and there usually isn't, when similar events occur.

The pilots also reported that the aircraft was unable to hold assigned altitude (and one must assume this means the autopilot rate of response or pitch trim limits to turbulence-induced deviations were exceeded), but it doesn't say whether the A/P remained engaged throughout the event, was disengaged by the pilots and the recovery hand-flown, or disengaged itself (as designed if exceeding internally-designed parameters) for the descent. It sounds like the crew did a good job managing the recovery through a quick descent as the situation at altitude became aerodynamically untenable.

If the ongoing assumption that there could have been a pitot heat/ADIRU/etc malfunction on AF447s is acceptable to this thread, then I submit that a no-malfuction scenario is as much of a possiblity, if not moreso, given the area of weather in which the aircraft was lost. Encountering ice-accrual of any significance that would exceed sublimation at FL350 outside a CB is an anomaly, with the coincidence of malfunctioning pitot heat making it a factor even more unlikely. On the other hand, the possibility of encountering moderate-to-severe turbulence in, around, or over developing hard-to-detect CBs (especially in a large, dynamic, steady state area of them where dissipating cells and ITCZ conditions feed developing ones) isn't, given the limitations of airborne weather radar.

badgerh

26th Jun 2009, 07:21

Wes Wal,

You received two emails in quick succession. Can you please check the headers to see if they came from the same place? If you use Outlook, click on "view" then "options" and you will get the complete "Internet headers"

If they are not from the same location, this implies very strongly a fake.

Thanks
Andrew

Flightmech

26th Jun 2009, 08:10

mickk,

Any aircraft can be struck by lightning, and lose part of the wingtip in the process. No significance to the 330 there:=

spannerhead

26th Jun 2009, 08:45

The lightning strike damage to the BD 330 was minor burns (nothing unusual) to the right hand wing tip. It was removed upon return to LHR to facilitate a minor repair. (easier to carry out 'off wing' than 'on'). Chinese whispers.

Panman

26th Jun 2009, 09:02

The entire right wingtip appeared to have detached during the thurnderstorm encounter sincei t was found missing on arrival. Despite the damage, the pilots made an uneventful landing.

Was about to say that the BD wingtip missing on arrival was a load of crap.

I was involved in removing the tip in the hangar last Friday.

prayingmantis

26th Jun 2009, 10:05

Badgerh,

Both NTSB emails were from the same place, with the same headers - they both originated from the NTSB. I received the same emails. Living in DC, I was paying more attention to the Metro crash update, but the second one was useful too! :-) A WSJ article this morning also references both occurrences mentioned in the NTSB press releases.

I propose any future posters who doubt the NTSB release to please call their main office, (202) 314-6100 or contact Ted Lopatkiewicz, [email protected] - they might even provide more information, as the NTSB listserv to which I subscribe is sometimes a bit short on details.

-Chris

takata

26th Jun 2009, 10:19

Thank you both for the confirmation by posting those e-mail headers.
The NTSB page isn't still updated, but at least, we can be sure that this news is genuine without any doubt. There was so much unreliable informations published about this case that it is always better to verify every source as far as possible.

By the way, this would mean that at least one of Northwest A330s fleet was still flying with THALES C16195AA pitots probes and wasn't upgraded before this June 25th incident, or was it with the new model? It would be interesting to know the full story. TAM communicated early June that they had changed all the probes on their fleet.

Additionnaly, this change isn't really a big deal of $$$: an Air France ground crew declared that it was a 15 mn work per probe and each would cost around $500. The question remains if this would fix those issues of unreliable Air data in severe icing conditions at cruise level.

S~
Olivier

steamchicken

26th Jun 2009, 10:51

Would you be confident in putting the control system back from its fail-safe mode into its normal mode, knowing that one of the critical data sources was untrustworthy? Note that it behaved as it was designed to, reacting to loss of data by moving from Normal Law (with lots of computerised protections that depend critically on this data) to Alternate Law (with fewer protections that don't).

After the speed indication came back on line, it was still true that it was now an unreliable data source. It seems more than sensible that, if it isn't safe to use normal with unreliable speed indication, it isn't safe to use it until the speed indication has been *proven* to be reliable again. The word unreliable doesn't mean permanently broken, it means that you can't rely on it.

SaturnV

26th Jun 2009, 11:22

unclemohammed, Lopatkiewicz is the Director of Public Affairs. The LOPATKT@ address is probably used by him when functioning as Director of that office. Lopatt@ is probably used as a media contact address for specific incidents. It is not unheard of for government officials to have more than one email address.
The lopatt@ appears in other NTSB releases as the media contact.

As to errors in style or syntax, Lopatkiewicz doesn't follow the government style manual in this release, or in other releases in which his name appears as the contact person. For example, 5 is written numerically, the style manual would prescribe "five".

Finally, its possible that a summer intern wrote the release. The NTSB Public Affairs Office is quite busy with the investigation of a serious subway accident in Washington DC earlier this week, amd I would think that Lopatkiewicz is rather busy arranging for NTSB press conferences and briefings.

Orestes

26th Jun 2009, 11:30

The alleged NTSB e-mail mentions a sudden "drop" in air temperature - meaning it suddenly got colder? That seems counterintuitive - I had thought the more likely danger was the sudden increase in air temperature associated with these weather systems. I'm confused....

barit1

26th Jun 2009, 12:10

Consider something here:

SAT is impossible to measure directly @ M0.8+ and FL350. The displayed SAT is a computed number, based on measured TAT, with the ram temperature rise (a function of Mach) "backed out".

If the pitot is blocked, then the computed ram rise is in error. Depending on altitude excursions, this error could be either plus or minus direction.

Ergo, the computed SAT could be in error either direction.

SLFJB

26th Jun 2009, 12:33

Tiscali reporting that one of the bodies recovered from AF447, has been identified: See link below

Briton's body recovered from crash (http://www.tiscali.co.uk/news/pa/uknews/2009/06/26/briton-s-body-recovered-from-crash.html?lpos=news_ticker&lid=Briton%27s%20body%20recovered%20from%20crash)

My Question : The passengers would have been issued with seat numbers. Would Air France retain this information, and assuming that most people would be seated on a night flight, would this help to identify where the plane broke apart? (I.e. Near the wings as suggested , or at the VS)

Dutch Bru

26th Jun 2009, 13:09

The site:
NTSB - Press Releases (http://www.ntsb.gov/Pressrel/pressrel.htm)
The release:
Press Advisory (http://www.ntsb.gov/Pressrel/2009/090625a.html)

DJ77

26th Jun 2009, 13:29

From PJ2:
don't the GE installations use EPR?

As far as I know, GE-CF6 and GE90 series always used N1 as driving parameter.

Also, Nara is a medium size town abt 15 miles east of Osaka, jpn. This looks like a typo for Naha.

SaturnV

26th Jun 2009, 13:38

My Question : The passengers would have been issued with seat numbers. Would Air France retain this information, and assuming that most people would be seated on a night flight, would this help to identify where the plane broke apart? (I.e. Near the wings as suggested , or at the VS)
SLEJB,

In both AI182 and TW800, the recovered bodies of passengers were matched with seat assignments, as well as the results of the post-mortem autopsies. The information can be quite helpful in determining the cause or sequence of a mid-air break-up. Even if bodies aren;'t recovered, that can be telling. For example, in TW800, bodies were never recovered for several rows of passengers seated directly above the center tank.

Hyperveloce

26th Jun 2009, 13:43

The site:
NTSB - Press Releases (http://www.ntsb.gov/Pressrel/pressrel.htm)
The release:
Press Advisory (http://www.ntsb.gov/Pressrel/2009/090625a.html)

Ok, now it is official.
Could the NTSB impose mandatory airworthiness directives about Pitot probes although the AESA seems reluctant to do so ?
Jeff

SaturnV

26th Jun 2009, 13:48

Ok, now it is official.
Could the NTSB impose mandatory airworthiness directives about Pitot probes although the AESA seems reluctant to do so
Hyperveloce, the NTSB can investigate and make recommendations to a regulating agency that a certain action be taken. The FAA, as a regulatory agency, would issue any ADs.

The NTSB's recommendations are not binding on a regulatory agency.

In this instance, the NTSB has authority to investigate, as one flight originated in the United States, and the other flight was a U.S. airline

PJ2

26th Jun 2009, 14:15

DJ77;
As far as I know, GE-CF6 and GE90 series always used N1 as driving parameter.

Also, Nara is a medium size town abt 15 miles east of Osaka, jpn. This looks like a typo for Naha.
Yes, you're right, thank you, and the Trents are EPR, I recall now.

I found the town of Nara but was thinking of the name of the FIR. The "Naha" typo is immaterial now I suppose.

YRP

26th Jun 2009, 14:44

Originally posted by xcitation:

At the end of the day I can't understand how one sensor (ok 3 redundant pitots) can take out something as critical as an entire flight system. It appears that there are too many dependencies in the software that causes the pitot failure to initiate a chain of software errors that are not handled. Instead the errors cascade to secondary software modules which go into failed state. Good electronic/software design seeks to minimize coupling and un-necessary dependencies. Error exceptions are handled gracefully and trapped.

The problem with redundancy is when there are common fault cases. For example if (hypothetically - not implying this happened with AF447) there is a certain environmental condition where a pitot sensor is susceptible to icing, this might apply to all three.

With three failed pitot sensors, there ain't a whole bunch clever software can do. Even with two failures, you have a big problem - two incorrect sensors in agreement with each other, or possibly three all disagreeing.

But be careful about blaming automation for this. How much better would a human pilot do with three separate sensors connected to three separate airspeed indicators? If indeed there is a pitot icing problem here, the problem is a mechanical/physical pitot/static sensor design problem NOT one in the software/automation.

FlyingOfficerKite

26th Jun 2009, 15:14

Interesting that the body of the Captain has been found along with some of the passengers and cabin crew.

I wonder it he was in the cabin rather than the flightdeck at the time of the accident?

FOK

Dutch Bru

26th Jun 2009, 15:36

A report dating from January 1999 (nr. 5X002-0/98) by the German NSTB (the Bundesstelle fur Flugunfallundersuchung BFU) is a very interesting read vis-à-vis pitot icing on Airbus a/c.

The report concretely deals with a serious incident on an A320-200 in a holding pattern near Frankfurt (with PROBE/WINDOW HEAT on AUTO), when, in heavy icing, rain showers and turbulence, the speed indications on both Primary Flight Displays as well as on the stby-indicator disappeared. The A/P and A/T disconnected and several associated warning and failure messages were generated. If I understand things correctly, the a/c had gone into Direct Law, since the report mentions that the PIC stabilised the a/c at 10000 ft using horizon and engine power (PITCH and POWER). Shortly after stabilisation at that altitude all three speed indications returned. For the landing A/P and A/T were again available.

It is interesting that the report notes that the AIRPLANE OPERATING MANUAL states that when comparison between both ADR systems is impossible (ADR-DISAGREE) and the stby system isn't available either, as was the case here, the flight crew should act on their own discretion and experience.

Even more interesting the report (I repeat from 1999) notes that "disappearing speed indications in certain weather conditions have been notified by several A320 operators". And that "in 1993 Airbus had issued SB 34.10.00.011, addressing that specific problem", and had "informed all operators of A320, A321, A330 and A340". The report continues to note that "with the information note and with the experiences in daily operations it is a principle fact that all operators and maintenance organisations were bearing knowledge of weather related anomalies in the speed indication systems of certain Airbus types". However, the report also states that maintenance organisations were not given any indications for further measures.

The report concludes that because of the particular construction of the probes, unlimited flight of these a/c types in heavy rain and icing conditions is not possible. Reason why the BFU has issued the following safety recommendation:

01/99: The specification for the pitot probes should be modified in such a way that unlimited flight in heavy rain and icing conditions is possible. The application of the already developed improved pitot probes for all aircraft types (A320, A321, A330, A340) addressed in SIL 34-047 should be made mandatory.

Graybeard

26th Jun 2009, 15:43

"..How much better would a human pilot do with three separate sensors connected to three separate airspeed indicators? If indeed there is a pitot icing problem here, the problem is a mechanical/physical pitot/static sensor design problem NOT one in the software/automation."

I can visualize a PF saying, "Hey, my airspeed is falling off." The PNF replies, "Mine, too; and so is the standby, just like that recent advisory."

PF then disconnects the automatics and flies attitude.

Meanwhile, the automatics behave exactly as they were programmed 15 years ago. They didn't read the advisory..

GB

jcarlosgon

26th Jun 2009, 16:07

Qoute: "The report concretely deals with a serious incident on an A320-200 in a holding pattern near Frankfurt (with PROBE/WINDOW HEAT on AUTO), when, in heavy icing, rain showers and turbulence, the speed indications on both Primary Flight Displays as well as on the stby-indicator disappeared. The A/P and A/T disconnected and several associated warning and failure messages were generated. If I understand things correctly, the a/c had gone into Direct Law, since the report mentions that the PIC stabilised the a/c at 10000 ft using horizon and engine power (PITCH and POWER). Shortly after stabilisation at that altitude all three speed indications returned. For the landing A/P and A/T were again available."

If they were on direct law, they were lucky, IMHO. In alternate law, if IAS goes to a (right or wrong) low figure one has to pull the stick to avoid nose down automatic command (and the contrary for high - right or wrong - IAS reading). The problem seems to be on who decides what law to go to. It is the system’s decision, not the pilot’s. I wish I had a switch I could flip (no push button) into direct law in these cases, avoiding alternate law and its “protection” from too low/high right/wrong speed readings. Then it would be easier to maintain the required pitch.

Another subject, unreliable IAS procedure: I fly both GEs and PWs. GEs have N1 as the main thrust setting, PWs have EPR. For both types the Procedure shows only N1 settings for unreliable IAS, which is good. EPR is unstable and dependant on ice on probes, as well.

PJ2

26th Jun 2009, 16:34

YRP;
But be careful about blaming automation for this. How much better would a human pilot do with three separate sensors connected to three separate airspeed indicators? If indeed there is a pitot icing problem here, the problem is a mechanical/physical pitot/static sensor design problem NOT one in the software/automation.[my italicizing/bolding]:

Very well stated. In fact, (if I may beg the indulgence of the mods for a moment), from designer to pilot, the notion you have expressed is fundamental to any comprehension of what is at the heart of "automated" flight. Software that can exercise human judgement (as when a pilot must make a judgement based upon 'what is reasonable'), has yet to be written not because it is difficult technically but because it is difficult philosophically as anyone fascinated by Turing and the notion of AI will attest.

The notion, "philosophically", is not meant in any ethical sense - it is not a "should we or shouldn't we?" question, it is a question of 'understanding what human understanding and judgement means'. Further, the act of understanding "understanding" is itself, a philosophical act.

And when we "understand" (or 'see'), we do so in a particular way and not just any way. Our "seeing" is a particular template and not a mere objective act from which we can then derive "objective" data or perceptions.

This is an implicit limitation on knowing what "human judgement" is, in the same way that Heisenberg thought of uncertainty when he posited the notion that the act of measurement itself, affects that which is measured.

In other words, our perceptions or, the "way" we perceive, are not innocent nor are they given - thus understanding judgement is an elusive project which demands not a technical understanding but a philosophical one.

Hopefully that circuitous discussion of your point regarding automation will add to understanding why designing and writing software to "mimic" human responses (ie, judgement) is a different-order problem and not an "automation" problem per se.

Graybeard;
PF saying, "Hey, my airspeed is falling off." The PNF replies, "Mine, too; and so is the standby, just like that recent advisory."

PF then disconnects the automatics and flies attitude.

Meanwhile, the automatics behave exactly as they were programmed 15 years ago. They didn't read the advisory..
Precisely the point, said in much clearer terms!

PJ2

EGMA

26th Jun 2009, 16:57

Excellent point made by Graybeard.

Have we not gone full circle?

Before CRM we had the FO content to watch the Captain fly the aircraft into the deck because he thought the Captain was perfection personified.

Now we have an entire crew trusting a perfect flight computer, unable to hit the 'manual' switch because it's not in the SOPs.

PJ2

26th Jun 2009, 17:10

EGMA;
Now we have an entire crew trusting a perfect flight computer, unable to hit the 'manual' switch because it's not in the SOPs.
Well, trusting an airplane is what a pilot must do - that isn't the issue, but I think I understand what you mean.

The issue with automation is a two-pronged fork which the industry must deal with. Many of us saw this coming and said this more than twenty years ago when the 320 was first introduced - reliance on automation is as much a management/cost issue as it is a training issue. Automation is a bean-counter's dream because they have been sold the bill of goods that "these airplanes fly themselves" and so pilot costs can be reduced as can training costs. I know many (including myself) who never agreed with this approach, could see it happening, and wrote then as now, about the issue. We have now arrived at the point first seen back then and the industry must deal with it.

PJ2

UNCTUOUS

26th Jun 2009, 17:16

NTSB release:
two recent incidents in which airspeed and altitude indications in the cockpits of Airbus A-330 aircraft may have malfunctioned. The first incident occurred May 21, 2009, when TAM Airlines flight 8091 (Brazilian registration PT-MVB) flying from Miami, Florida to Sao Paulo, Brazil, experienced a loss of primary speed and altitude information while in cruise flight. Initial reports indicate that the flight crew noted an abrupt drop in indicated outside air temperature, followed by the loss of the Air Data Reference System and disconnections of the autopilot and auto-thrust, along with the loss of speed and altitude information.
Just theorising here (and whilst ignorant of the actual A330 system design); I asked myself "what physical phenomenon could cause a sudden loss of both airspeed and altitude info in a system reliant upon Air Data Reference Units for so many inter-dependent flight control functions?". and "Why the abrupt drop in IOAT?"
.
I surmised that it would not be solely due to water ingress into (or freezing within) the pitot pressure lines and could only be due to a more insidious pneumatic error, most likely one within the aircraft's static pressure lines. So, a leak or locked pressure?
.
Assume that one (only) static line becomes contaminated by water and that this water contaminant freezes and expands in the high-level cruise - at a low point "water-trap" in the static system. The ADIRU comparator function now has a growing problem integrating and resolving ALL its static inputs. Because it must assimilate inherent minor differences in the various sensed statics, the system won’t fuss over minor errors in quantum, particularly not over one that arises in the stable cruise. However it would if a line froze up in a climb, because the error rate would be much higher. The static pressure that feeds the barometric height function of the autopilot is now compromised by the error but, in the level cruise, the error is latent and the error-rate isn't rapid enough or yet large enough to excite an ADIRU disagree trip and the aircraft will either climb or descend (very gradually at first).
.
Why will it do that? and why will the flight-crew not notice? Will it climb or descend?
.
During the finite period that the error is compounding, the autopilot's barometric function will maintain (what it interprets to be) the FL350 pressure surface and FL350 will be consistently displayed. However, because of the locked static pressure, that "pseudo level" will not accord to a "real" FL350 at the actual standard pressure datum (QNE: 1013Hpa). The aircraft will actually be climbing due to fuel burn-off, but all the pilots will see over this period is an infinitesimal progressive change in pitch attitude and they'll not notice the minuscule movements (if any) in elevator auto-trim. Postulating here a gradual and insidious error due to a compromised static feed to at least one ADIRU, an error magnitude that's initially below the threshold at which an ADIRU comparator disagree will trigger. Speed would bleed off gradually (see post 2265 ( http://www.pprune.org/rumours-news/376433-af447-114.html#post5017176)for the reason) - except that the auto-throttle will be gradually increasing thrust, (albeit minimally) to maintain the stipulated IAS. The actual IAS will however be higher (and will climb gradually).
.
Ultimately however, once a disagreement trip is triggered by error size, what could happen?
.
The ADIRU affected by the compromised static line will trip off as the error size becomes untenable.... and the others will then reject its distorting static pressure contributions.
.
What will suddenly happen to the displayed IAS/MACH, altitude, IOAT and autopilot functions at that point?
.
The speed will change drastically (i.e. increase suddenly to a correct value), the altimeters will jump to the actual increased altitude and the autopilot will disconnect. Auto-thrust will quit and the IOAT will suddenly drop to the true value at the increased altitude (assuming here that it's sensed within the static system).
.
What could trigger a loss of control? Firstly the aircraft's actual altitude (and speed), when the ADIRU "fails", will be nearer to, or even above, coffin corner and sudden manual flight (particularly in Alternate Law) can be quite marginal at that point, particularly if the pilots see the sudden change of IAS/Mach and altitude as an error (rather than what it is, a leap back to reality)..... and inadvertently react with large or uncoordinated manual inputs.
.
Why wouldn't this malfunction scenario be later detected in the aircraft that have survived such encounters?
.
Firstly there's a presumption of pitot probe misbehavior.
Secondly, unless trapped water accumulates such that it can be drained from a limited number of static system low point traps, the water may or may not be detected nor drained (or even if it is, will not be seen as the real villain in the piece).
.
To accept this theory you need to suspend disbelief in the incorruptible infallibility of displays not annunciating errors, have some knowledge of what an ice-locked static pressure can insidiously do to an automated system, believe that computer software programmers just would not have accommodated such a scenario - and do quite a bit of lateral thinking about a cumulative growing error due to burn-off. In respect of inherent software errors, we have the example of the Turkish 737 at Amsterdam for a precursor (i.e. it shows what a RADALT indication glitch, not an annunciated RADALT failure, can do to a flight control system).
.
How does water get into static lines? Does it happen inflight or on the ground?
.
Water ingress is most likely to occur on the ground. In heavy rain water running down fuselage sides can be "sucked in" - in an atmospheric pressure-dropping environment. In some aircraft the static port "bungs" used to plug upwards into the static port but they were also hollow to equalize the pressure. Rain-water running down these hollow bungs would still be sucked up into the system. Nowadays the static ports are left "unbunged" and are usually a number of small holes (about 5 to 15) grouped together, to defeat insect entry. Small diameter holes won't defeat rainwater ingress however.
Why would this process be happening nowadays and not earlier in the A330/A340's life? Minor changes in hardware, software, maintenance routines or operating procedures can introduce unintended consequences. Changes in operating procedures? Perhaps crews are flying higher earlier with lighter load factors.
.
Posts 2406 (http://www.pprune.org/rumours-news/376433-af447-121.html#post5022915)) and 2408 ( http://www.pprune.org/rumours-news/376433-af447-121.html#post5022974) - are also pertinent to this theory.
.
Don’t shoot the speculator. If you don’t like the premise, postulate a more credible scenario…. preferably one that explains how an iced pitot can affect altitude.
.

24victor

26th Jun 2009, 17:23

Orestes wrote

The alleged NTSB e-mail mentions a sudden "drop" in air temperature - meaning it suddenly got colder? That seems counterintuitive - I had thought the more likely danger was the sudden increase in air temperature associated with these weather systems. I'm confused....

Conventional wisdom has it that you can't pick up heavy icing in the upper flight levels. Practical experience would suggest you can. If the NW incident reported by the NTSB is factually accurate they lost static as well, which I find hard to fathom. Does that mean they lost rudder limiting as well as the indicated speeds rolled back?

I had this recently from a mate of mine flying BBJs but with a lot of tropical heavy experience. He wrote;

Came back from SIN the other day and had ISA +28 at FL 360 going through some weather system. It must have been the beginning of a cyclone.We were 2000ft below Max Alt before we entered.Once in cloud Max alt came down to FL 360.Never seen a temp like that before.

High temps. Low temps. Ice where it shouldn't be. Rain at FL390! Someone remarked at the start of the first thread about Al Gore claiming responsibility under the guise of climate change. I grinned, but maybe there's something to it. We know a lot more now about windshear and microbursts and we're learning more about SCD. Maybe, like these phenomena, icing, rain and rapidly varying temps in the upper Flight Levels have always been there and we just didn't (collectively) know it.

Rgds.

24V

Squawk_ident

26th Jun 2009, 17:26

According to the website of the French newspaper "Le Figaro" dated yesterday evening

Le Figaro - France : AF 447*: les corps du piloteet d'un steward identifiés (http://www.lefigaro.fr/actualite-france/2009/06/26/01016-20090626ARTFIG00005-af-447-les-corps-du-pilote-et-d-un-steward-identifies-.php)

.../...
Partial translation

The BEA in charge of the inquiry announced that it would publish its first report Tuesday.
No track is officially turned down.
The Brazilian authorities identified Tuesday the body of the commander of flight AF 447, Marc Dubois, and the one of a steward. The information was confirmed Thursday by the direction of Air France.
These two new identifications thus change the number of victims identified from 11 to 13 out of the 50 bodies retrieved from the South Atlantic. The confirmation of this information by Air France and not by the BEA in charge of the inquiry, confirms a certain uneasiness with the Brazilian authorities. Those indeed have not accepted within their teams the French doctor sent by the BEA who came back without informations.
The BEA on the other hand announced that it would publish officially its report on the accident on Tuesday. Until there the investigation could accelerate if the black boxes of the plane were located and found.
According to several sources contacted Thursday, the French Forces have indeed picked up a signal, “they are turning around it for a few days to locate it”, explains a military source. “The question is now rather to know if the transmitter is still interdependent of the black box considering the conditions of the accident”, explains a source close to the file.

.../...

Things started to get confusing I would say. It would mean that the previous information published by "Le Monde" on the 23th and rapidly denied by the BEA was correct after all?

cribbagepeg

26th Jun 2009, 18:09

Here's where the much earlier comment about supercooled water could come into play. As I understand it, the term refers to water that has not passed from the liquid to solid state despite being below the freezing point. This can happen when cooling takes place very quickly, and in the absence of both mechanical forces AND particulate matter such as dust, around which crystals would normally begin to form. I've long since forgotten the physics, maybe something to do with the expansion and subsequent contraction of the droplet which would normally happen during "graceful" cooling.

BAM, the supercooled droplet undergoes mechanical stress, upsetting the delicate supercooled state, and it solidifies upon contact with the AC.
From here, I get lost in the thermodynamics of sublimation, melting and
eventual equilibrium. It strikes me, however, that a relatively large mass
of supercooled water (now ice) forming VERY suddenly might take a few
or many seconds to clear, even with fairly powerful heaters - remembering that latent heat of fusion thing....

EGMA

26th Jun 2009, 18:09

I agree PJ2, I've been involved in computing for the last 25 years and know full well that perfect software is unobtainable. I also understand the difference between good and good enough.

It looks like we're following man's usual stepping stones to progress; one disaster after another ...

Hyperveloce

26th Jun 2009, 18:09

to Squawk_ident: the press communique from the BEA of the 23th of June did not necessarily suggest that the information from "Le Monde" was erroneous, but rather maybe that in the absence of a positive identification of the signals having been picked up, the press release was deemed as prematured (the BEA said that any established fact will be made public).
Jeff

bratschewurst

26th Jun 2009, 18:14

Instrusion from SPL; disregard as desired.

The problem with redundancy is when there are common fault cases. For example if (hypothetically - not implying this happened with AF447) there is a certain environmental condition where a pitot sensor is susceptible to icing, this might apply to all three.

Reminiscent of the BA 747 losing all four engines from flying through a cloud of volcanic ash, or the L-1011 that lost two engines (and most of the thrust from the third) due to losing oil from not having the oil plugs replaced after a check of some kind.

With three failed pitot sensors, there ain't a whole bunch clever software can do. Even with two failures, you have a big problem - two incorrect sensors in agreement with each other, or possibly three all disagreeing

Garbage in, garbage out is the saying in the software business.

If indeed there is a pitot icing problem here, the problem is a mechanical/physical pitot/static sensor design problem NOT one in the software/automation.

Except that the software’s response to the issue could be better. Why not have the A/P go into attitude hold in this case, instead of simply disconnect? A given attitude and power setting will result in sufficient airspeed stability to at least assess the problem without having to wrestle with the airplane at the same time.

If they were on direct law, they were lucky, IMHO. In alternate law, if IAS goes to a (right or wrong) low figure one has to pull the stick to avoid nose down automatic command (and the contrary for high - right or wrong - IAS reading).

What’s the design justification for even having altenate law? Wouldn’t it be better for the pilot simply to know that the normal law envelope protections are gone, rather than have to remember which subset of them are still in effect? In some ways, partial envelope protection (if that’s what alternate law provides) is worse than none at all – especially if the transition occurs at a difficult moment, as seems to be inherently the case.

Graybeard

26th Jun 2009, 18:44

Just received this from friend, Rafael, appended to the NW pilot's email:

"Rafael, I just drove a Boeing 747-400 through this same area on the same day. We were circumnavigating a typhoon. The old timers at United taught us young kids to operate the radar in max gain at high altitude to avoid dry tops. I ended up at FL410 and due to strong down drafts we required max power to hold on to our airspeed. Lots of zig zagging, but not one drop of visible moisture. Fly fast, H."

This is factual; I remember H. when he was a kid at our local airport. His Dad retired from UAL as Capt on the -400.

GB

Squawk_ident

26th Jun 2009, 19:09

Hyperveloce

Of course the BEA is considering sacred all informations especially if it come only and solely filtered and originated from them. Now I don't see the French Navy and very likely other vessels from other Navy making circles around whales talking (someone - not on this forum - thought that he had to say that in case there might be some confusions). And now it is a fact that a signal is received because I can't think one second (might be wrong) that all the people on board these boats do not exactly know what noise or signal they are looking for.
Wait and see mais le temps passe...

Flyinheavy

26th Jun 2009, 20:02

I want to strongly confirm that I am not 'anti-Airbus', BUT this is giving me goose bumps:

It is interesting that the report notes that the AIRPLANE OPERATING MANUAL states that when comparison between both ADR systems is impossible (ADR-DISAGREE) and the stby system isn't available either, as was the case here, the flight crew should act on their own discretion and experience. Does that mean in a situation like this the pilots are left alone completely and supposed to find out how to overcome it? That is what I ment earlier with machine-human interface. I am not as naively as to think that one could take care of any thinkable problem, but leaving the user of a highly computerized system alone when it breaks down, without giving some advice how to safe the day, is simply unacceptably. Or does it arrogantly implicate that a situation like this never ever could exist? This on an a/c that 'anybody' could fly?

Quote:
If they were on direct law, they were lucky, IMHO. In alternate law, if IAS goes to a (right or wrong) low figure one has to pull the stick to avoid nose down automatic command (and the contrary for high - right or wrong - IAS reading). What’s the design justification for even having altenate law? Wouldn’t it be better for the pilot simply to know that the normal law envelope protections are gone, rather than have to remember which subset of them are still in effect? In some ways, partial envelope protection (if that’s what alternate law provides) is worse than none at all – especially if the transition occurs at a difficult moment, as seems to be inherently the case.Not only ONE 'Altn Law', there are TWO with slight differences protectionwise. So it is even more complicated.

Why do we as pilots accept something like this?

I am positively not against modernization, but I do have problems with accepting a system that rather cold calculates the 10^9 case and more or less pushes the pilot out of the loop. This is my oppinion, but as far as I remember, air law in any country holds us primarily responsible for the safety of persons on bord. Did we give up on this?

Will Fraser

26th Jun 2009, 20:25

YRP

I disagree fundamentally with your position. "It isn't the software/automation". I proposed early on that the interface between Otto and flying pilots is weak and in an out of balance "command" way. It is too quick and too absolute, seemingly wonderful traits, but deadly under certain circumstances. Pilots are comfortable (too much so) when things go pear and the computers make command decisions that are precipitous, and leave the ultimate pilot out of "the loop".

Imagine flying along fat and happy, and in less time than one can belch, the box cascades decisions and reports to be assimilated immediately with the a/c and its contents at risk!! Dark, turbulent, seven miles up, and the box hands two people two folders of data, to be understood and acted upon whilst the seats under your primitive "cheeks gyro" are telling you you have one half second to input a control.

The previous reports of similar loss of data flow involved less than harrowing conditions, and were successfully escaped; conclusions about those incidents are being debated even now, and you are at ease with the highly possible loss of data, panel, as, etc. to be dumped unceremoniously on the pilots laps???

This interface is the 400 kg gorilla no one seems to be discussing.

manrow

26th Jun 2009, 20:40

Have we yet reached the point where the recorders are no longer functioning?

beamender99

26th Jun 2009, 20:51

JD-EE

The NTSB were very tardy in adding this report to the index.
It is oh so simple today to find it.
Yesterday the lack of the index item was causing many to question if it was a a genuine report hence all the chat about it.

RetiredF4

26th Jun 2009, 21:25

Quote: bratchewurst

Except that the software’s response to the issue could be better. Why not have the A/P go into attitude hold in this case, instead of simply disconnect? A given attitude and power setting will result in sufficient airspeed stability to at least assess the problem without having to wrestle with the airplane at the same time.

isn´t that the real problem nowadays? Is the Crew in the cockpit for studying panels and manuals or are those Pilots there to act like pilots?

In my days the first item in any kind of emergency was

Maintain Aircraft Control

Reading Checklist items came after that.
The big difference probably being that we had to wrestle with the aircraft also without any kind of emergencies.

With this answer here i do not intend to blame the Crew of AF447 for acting wrong, there are no informations to that.

Pontius Navigator

26th Jun 2009, 21:33

Have we yet reached the point where the recorders are no longer functioning?

Theoretically no.

There have been reports that the French Navy has heard something. Now I am wracking my brains to remember what is needed next.

For a single point detection you will have an approximate bearing and signal strength. Given the short maximum range the probable position will be quite small.

Detecting from a different position with then enable them to reduce the area of probability and so on.

An alternative and more accurate method would be simultaneous detection of a pulse from 3 hydrophones. The position could them be determined through hyperbolic reduction. You would get a position within 200-300 metres.

jeremiahrex

26th Jun 2009, 23:29

What’s the design justification for even having altenate law? Wouldn’t it be better for the pilot simply to know that the normal law envelope protections are gone, rather than have to remember which subset of them are still in effect? In some ways, partial envelope protection (if that’s what alternate law provides) is worse than none at all – especially if the transition occurs at a difficult moment, as seems to be inherently the case.This highlights what I have seen a lot on this forum: the lack of differentiation between automation, control systems and flight protection systems. Unless you have the autopilot on, the airplane is not making any flight decisions for you. The flight envelope protections LIMIT your control inputs but they do not make control inputs for you. These limits are calculated on the fly (haha) by the computers using the available flight data, according to some extremely complex models about the aircraft, and then padded a little bit for stability (as in, derated to be on the safe side). Other than that, the inputs made on the sidestick (or the yoke on a Boeing aircraft) are modified by a gain and then transmitted on.

The autopilot is another matter, being a feedback system that trys to keep a control variable at a given value. This system GENERATES flight control inputs. FEP limits flight control inputs, but does not generate them.

As for why you'd want alternate laws, not all the protections rely on every peice of sensor data. Why give up ALL protections if you only need to give up one? For whatever reason, the concepts of modes of operation are very common in many industries. The idea being that a person can associate a number of states with just a single name. I'd assume that Boeing would have a similar mechanism for degrading the flight protections but I can't find any verification for this right now.

As for the "interface", there is no real interface. Someone in this thread has mentioned this multiple times. The sidestick functions exactly the same in every law. The only difference with FEP is that if you slam the sidestick to one side then you won't crash the aircraft. The FEP system reduces pilot workload by making it so s/he doesn't have to concentrate strictly on keeping the airplane aloft, but on providing it a course.

I don't understand why these concepts do not seem to stick.

HarryMann

26th Jun 2009, 23:32

Is that saying they have searched an area 'visually' corresponding to 350,000 km. sq. !

Britain has a surface area of 244,820 km. sq.

And 'electronically' searched an area of 2 million km. sq !

michaell

26th Jun 2009, 23:48

Google translation:

:: FAB - Brazilian Air Force::

26/06/2009 - 19h02
Final Note - 26.06.09

TERMINATION OF THE SEARCHES OF AIR FRANCE FLIGHT 447

Command and the Navy Command of the Air report that at the end of today, June 26, was officially given by the end of the largest and most complex operation of Search and Rescue has already carried out by Brazilian armed forces in sea area, both in appearance duration as the magnitude of the means employed.

In these 26 days to search the passengers and crew of Air France flight 447, which disappeared when they flew on the route Rio de Janeiro (RJ) - Paris (France), on the night of May 31, 2009 were 51 bodies and rescued more than 600 parts and structural components of the aircraft, and several bags.

The technical reason that determined the end of the search is the impracticability of sights survivors or bodies, primary objective of the operation, already 26 days after the accident. The day on June 12th to 26th, a period of 15 days, only two bodies were recovered, and the last on 17. In the last nine days, no body has been sighted or prey.

The 51 recovered bodies were delivered to the Federal Police and the Department of Social Defense of Pernambuco to the work of identification. The wreckage of the aircraft and luggage collected were delivered to the Bureau d'Investigations et D'Analysis of I'Aviation Pour la Securite Civile (BEA). Research on the factors that contributed to the accident is also the responsibility of the BEA and has the support of the corresponding sector, the Brazilian Center for Research and Prevention of Aeronautical Accidents (CENIPA).

In 26 days of continuous operation under the responsibility of Brazil, in response to the international search and rescue, the Brazilian Air Force used 12 aircraft and had the support of aircraft from France, U.S. and Spain. The Brazilian Navy has served in rotation with 11 ships in the area of search, totaling about 35 thousand miles navigated, approximately eight times the size of the Brazilian coast.

Were flown around 1500 hours and was conducted visual searches in an area corresponding to 350 thousand square kilometers, more than three times the size of the state of Pernambuco. The R-99 aircraft, in turn, electronic search conducted in an area corresponding to two million square kilometers, eight times the size of the state.

Were directly involved in the 1344 military operation of the Brazilian Navy and 268 from FAB, totaling more than 1,600 professionals in the tasks of search, rescue and support these activities.

Remain in the area to search the resources dedicated to marine capture emissions data and voice boxes of rugged aircraft, coordinated by France.
All the search operation was under the direct responsibility of the Department of Control of the airspace (DECEA) by means of Recife SALVAERO saved in coordination with the Northeast and attended to the provisions of Annex 12 to the Chicago Convention, effective in 1950, which establishes the commitment of signatory countries to the search and rescue operations in their areas of jurisdiction.

Mindful of its mission, the crew and other members of the Navy Command of the Air Command and make your way to work that day just to offer reverence to the pain that mark Brazilian families and the international community.

MEDIA CENTER OF MARINE
MEDIA CENTER OF AERONAUTICS

Will Fraser

26th Jun 2009, 23:56

To state 'there is no interface' is disingenuous. Since the beginning, tools are a characteristic of human existence. Learning to use a scythe develops an 'interface'. This attitude, I submit is what is wrong with at least some of the ABI philosophy. Instead of a 'tool' the automatics are proposed to be nothing less than a superior 'pilot', whose purpose is to 'protect' the airplane. Inherent in this language is an 'attitude' (a human one) of 'supremacy'.

Who protects the a/c from the 'box'??? A 'cleaning lady' can fly this a/c!!!

"What's it doing now?"

For anyone to state 'there is no interface' merely underscores the root of the problem and his/her own lack of understanding. IMHO. I think too, that a loss of sensors as is demonstrable prior to if not a part of this accident, presents an arguably suitable example of the differences involved in manual flight and a litany of pre-programmed failures that cascade from a manageable defect into a very dangerous reluctance of the computers to perform at even a very basic level of expectation.

Will

ArthurBorges

27th Jun 2009, 00:00

An AP item posted two hours ago on the French version of Yahoo cites USAF Col. Willie Berges, in charge of US forces participating in the search, as saying operations would continue for "at least another 16 days" and "we'll have a better picture on July 1st." He added the Brazilians and French would make the final call on when to terminate operations.

Callas

27th Jun 2009, 00:15

Air investigators, running out of time to find the "black boxes" with key information on the crash of Air France Flight 447, suspect a rapid chain of computer and equipment malfunctions stripped the crew of automation today's pilots typically rely on to control a big jetliner.
An international team of experts is building a scenario in which it believes a cascade of system failures, seemingly beginning with malfunctioning airspeed sensors, rapidly progressed to what appeared to be sweeping computer outages, according to people familiar with the probe. The Airbus A330, en route from Rio de Janeiro to Paris, crashed into the Atlantic Ocean during a storm 26 days ago, killing all 228 aboard.

Based on an analysis of the sketchy information from automatic maintenance messages sent by the aircraft, these people said, the plane bucked through heavy turbulence created by a thunderstorm without the full protection of its flight-control systems -- safeguards that experts say pilots now often take for granted.

Relying on backup instruments, the Air France pilots apparently struggled to restart flight-management computers even as their plane may have begun breaking up from excessive speed, according to theories developed by investigators.
The investigators stress it is too early to pinpoint specific causes. But whatever the eventual findings, the crash already is prompting questions about how thoroughly aviators are trained to cope with widespread computer glitches midflight.
If such emergencies do occur on today's increasingly automated jetliners, many industry safety experts wonder how proficient the average crew may be in trying to rely on less-sophisticated backup systems.
"The difficulty is, they're rare enough that pilots can be unprepared, but likely enough to pose a real threat," according to Bill Voss, president of the Flight Safety Foundation, an industry-supported group based in Alexandria, Va. "We need to examine how to deal with automation anomalies."
Unlike jetliners built in previous decades -- which required pilots to frequently manipulate controls and often manually fly the planes for long stretches -- newer computer-centric aircraft such as the A330 and Boeing's 777 are designed to operate almost entirely on automated systems. From choosing engine settings and routes to smoothing out the ride during turbulence and landing in low visibility, pilots essentially monitor instruments and seldom interfere with computerized commands. So when those electronic brains begin to act weirdly at 35,000 feet, the latest crop of aviators may be less comfortable stepping in and grabbing control of the airplane.

Airlines typically use simulators to train cockpit crews for such events, but a pilot may only hone skills to deal with major computer problems every few years. Pilots hardly ever experience multiple computer failures in real-world conditions.
Crews commanding a flotilla of specially-equipped vessels are still trolling an area with a radius of at least 50 miles for the black boxes -- the digital recorders containing detailed flight data and cockpit conversations from the flight. The sea floor beneath where debris was found floating is mountainous and up to 15,000 feet deep. The recorders are designed to have enough battery power to last for at least 30 days. That deadline runs out Wednesday, though investigators and safety experts believe that signals may last for at least a couple more weeks.
Because the A330 is one of the most widely used planes in commercial aviation, crash sleuths "aren't likely to easily stick with an undetermined cause," according to John Cox, a former Airbus pilot who now works as an industry consultant. Instead, investigators "will exhaust every possibility" to pinpoint probable reasons and contributing factors, Mr. Cox said, even without the black boxes, though they may have to be cautious about a definitive assessment.
In place of that data, they would use computer simulations to try to lay out the possible sequence of events, and then work backwards, eliminating as many potential causes as possible.
A progress report from French officials leading the probe could come as early as next week. At this point, the bulk of the information made public about the Air France tragedy deals with suspected problems with external speed sensors, or so-called pitot tubes, which have a history of icing up and malfunctioning on different Airbus models.
On Thursday, U.S. investigators disclosed two recent incidents in which they believe Airbus A330 jets suffered air-speed sensor malfunctions that led to more sweeping system failures. Both of those planes landed safely.
A Northwest Airlines A330 flying from Hong Kong to Tokyo earlier this week, for example, ran into a situation which investigators believe may be a similar to what took place on the flight deck of the Air France jet.
The Northwest crew reported entering a storm in daylight and running into turbulence; in less than a minute their primary and standby airspeed indicators showed the plane had slowed dramatically. Other systems that automatically maintain speed and altitude also disengaged. Things didn't return to normal for three minutes as the captain flew the aircraft out of the rain, according to information gathered by U.S. safety officials.
The scene inside Air France Flight 447 may have been more ominous from the beginning. The crew was flying at night and the storm they tried to traverse may have been more violent.
After the initial speed warnings, the Air France pilots are believed to have quickly lost the autopilot and automated throttle-controls, which are designed to instantly disengage when speed readings are suspect. Soon after, according to people familiar with the investigation, cockpit instruments showed a series of warnings about various other equipment failures and the crew apparently shut down or tried to reboot their primary and secondary computer systems.
It's not clear what happened next. But the pilots, perhaps distracted by wildly fluctuating airspeed indications, along with the cacophony of other cockpit warnings, could have allowed the jetliner to gain excessive speed that possibly tore off sections of the plane.
The aircraft could have accelerated and run into danger because faulty instruments convinced the Air France crew the twin-engine jet was traveling so slowly that it was close to stalling. That may have prompted them to rev up the engines or point the nose down to go faster.
One difficult question is whether all three air-speed sensors located on the lower curve of A330's nose -- including a backup device -- failed. If so, investigators are trying to understand whether the pilots followed procedures that call for maintaining engine power and whether they took other steps to ride out the emergency. Planes can -- and occasionally do -- fly safely without pitot probes functioning properly. That's why industry and government investigators believe some other important factor, which hasn't been identified yet, likely contributed to the crash.
Airlines are likely to pay more attention to helping pilots better understand the ripple effect that can occur when computerized flight controls, altitude indicators and other systems go haywire. There are detailed check lists for each chain of events, but to save on training time and cost, typically airlines limit simulator time for pilots to experience the full range of things that can go wrong.
"Such issues are talked about regularly during training," according to John Goglia, a former member of the National Transportation Safety Board, but "pilots only occasionally have the chance to practice" reverting to backup cockpit instruments and flying without the usual computerized systems.

24victor

27th Jun 2009, 00:26

The only difference with FEP is that if you slam the sidestick to one side then you won't crash the aircraft.

The corollory to that is if you haven't got enough control authority to crash the aircraft you probably haven't enough authority to recover it from a major upset either.

Your "padding" of the FEP limits may be the difference between recovery and disintegration and under current control laws this part of the envelope can't be entered. Despite stress predictions, ultimate load tests, failure path analysis and all the other good stuff, airframes do not necessarily break apart when overstressed as has been proven many times.

When it all goes pear shaped you want to be able to control the aircraft by whatever means necessary, not negotiate with it.

Rgds.

24V

JD-EE

27th Jun 2009, 00:37

Callas, without the attribution for your long message it's not worth the time it took to post it.

JD-EE

wozzo

27th Jun 2009, 00:38

PJ2

27th Jun 2009, 00:40

Will;
I think too, that a loss of sensors as is demonstrable prior to if not a part of this accident, presents an arguably suitable example of the differences involved in manual flight and a litany of pre-programmed failures that cascade from a manageable defect into a very dangerous reluctance of the computers to perform at even a very basic level of expectation.
First, I am not discussing the AF crew here or suggesting anything in the following points.

While I remain cognizant of the B2 accident at Guam, loss of sensors/sensor data does not, in and of itself, generally result in loss-of-control resulting in an accident. The QRH Unreliable Airspeed/ADR Failure drills are in place for such a loss and have been used to successfully maintain a safe flight path while recovering the necessary sensors. I have had this experience in a 767; there are recent incidents which attest to this understanding. Given only what we have, we can assume that the flight control computers did not stop functioning and that they were still controllable by the stick even as they reverted to alternate law even with the loss of PRIM1.

There is no special technique or training one needs for flight in alternate law; training is required for flight with unreliable speed, however, but such training, with shortened simulator times, (down to 3.5hr sessions in some cases) is rare.

In the absence of ACARS indications, we could conclude that it is not these computers which were in the cascade of failures; from what little is known from the ACARS, we can safely assume that the flight control primary and seconary computers (FCPC/FCSC), minus PRIM1, continued to function as expected at least until 02:14:59Z.

In 99.9% of all mode confusion occurrences on this and other automated aircraft, "What's it doing now?" is a statement about training and knowledge, not about the aircraft itself. Millions of hours of safe flight and millions of successful departures and arrivals attest to this. The 320/330/340 series aircraft can be hand-flown just like a 172. Not understanding what your aircraft 'is doing now' means an instant disconnection of the autoflight system until one has regained situational awareness inside and outside.

I think we probably agree if I am reading your statements as intended, that this isn't primarily an "airplane" problem. I think there are important things to say about 'pre-programmed' cascading failures but redundancy has it's own issues (as per a recent (linked) paper on the subject), as does a system which contemplates monitoring/judging like a human being to self-assess, "What am 'I' doing now?"

The apparent failure of a pitot-static system and the apparent consequent loss of possibly 3 ADIRUs (with attendant faults/failures) do not render the flight controls inoperable/uncontrollable - that's my only point. Again, I make no judgement here - I am merely unpacking the statement a bit.

Instead of a 'tool' the automatics are proposed to be nothing less than a superior 'pilot', whose purpose is to 'protect' the airplane. Inherent in this language is an 'attitude' (a human one) of 'supremacy'.
Well said. That was my initial impression when I first began to fly the 320 in 1992 and, while one learns one's aircraft as thoroughly as one can and I found the Airbus series a beautiful aircraft to fly, that impression, bolstered by some experiences, never fully left me. It is why I both defend the airplane and criticize it.

Will Fraser

27th Jun 2009, 01:20

PJ2

The B2 cannot be flown manually. At All. The e/series AB flies just fine by hand. Here is the dilemma: Until Flight crew are fully cognizant of the duality of the Airbus, and train its idiosyncracies, its interface with its crew will be not fully trained, a potentially hazardous situation. Knowing one's a/c is critical to safe flight. Stopping short of training criticism across different carriers, it is this flaw that needs attention.

Once that B2 pitched up past 10 degrees, the crew could have punched out without any repercussions from their commander. They stuck with it until it got ridiculous, and left the FD.
I'm sure the computers were 'puzzled', 'they' didn't know what hit 'them'.

More important than "What's it doing now?" might be: "What's it going to do?"

I appreciate your open mind as an AB pilot. It is after all a human problem.
The AB is a phenomenal a/c, what's missing is some assessment and remediation of human induced shortcomings, pilot and a/c.

Will

PJ2

27th Jun 2009, 02:20

Will;
I appreciate your open mind as an AB pilot. It is after all a human problem.
I remain an enthusiastic, open yet unconvinced (and now retired) AB pilot; my open mind is far grumpier and has been since 1992 about these broader matters than I will ever allow in my posts.

It is indeed, a human problem and it is, as I offered in the "philosophical" post, coming home to roost; it's trite to say it I know, but hubris is inappropriate where aviation is concerned.

Yes, I suspected the B2 couldnt' be flown manually given the kinds of flight controls it had and the probable need for neutral stability (making it impossible to fly without a computer), and that the guys stuck with it. I wonder though, how a potential single-point failure made it into production - almost certainly it was not an unknown.

ClippedCub

27th Jun 2009, 03:50

Would the A330 suffer Mach tuck??Mach tuck is well understood and the horizontal stabilizer will get you out.

Does raise a concept though, in the infamous 'coffin corner'

Assumptions

-Crew at 35k feet wouldn't have tactile sense of speed due to control forces and wind noise, assuming noise canceling headsets and tight speed range.

-Sailplane experience, (is that common in Europe starting out?), so they know what stall buffet is from thermaling.

Scenario

Pitots slowly build ice and computer advances auto throttles because computer thinks it's slowing down. Reach buffet boundary, get a split, autopilot disengages, master caution and warnings, crew notices ASI's are split, but low, confuse buffet with somehow being in a stall, advance power levers and push forward, when they're already at Vne say. Now we're hot in turbulence. Of course you were hot when the computer took you there in this scenario.

takata

27th Jun 2009, 05:54

emu787:
did the AFCS detect low speed - about to get a stall or low speed buffet boundary approaching (erroneous airspeed information) and the computer pitched the aircraft nose down and applied full power thinking this is the way to recover. This would almost certainly result in instantaneous excessive speed that would test the integrity of the airframe to its limit.It seems very improbable considering A/THR and AP OFF => Alternate Law2 (protection lost) due to unreliable Air Data (ADR disagree). Moreover, Air France ADIRUs (Honeywell) are different from Quanta's (Northrop-Grumman).

S~
Olivier

captplaystation

27th Jun 2009, 07:41

As a self confessed Airbus sceptic, the defenders of the genre may feel free to flame me, but . . . . last years Qantas incident made me squirm, now, after one has finally & inevitably gone in ,the pilot body and indeed the public in general, discover that we have (at least ) 2 more USA regulated incidents to be considered PLUS two more involving F-registered but not AF airframes PLUS 6 was it ? more occurences in the last year or so involving AF airframes .
So, without in any way wishing to over-emphasise due to my previously admitted bias, I must ask, for something which has in all likelihood finally come home to roost, what did Airbus previously have in mind to address the issue apart from crossing it's fingers and emphasising to crew that when the sh1t hits the fan you had better be damned good at finding and reading the right checklist/troubleshooting as your world turns inside out around you.
Very helpful or what ?
And short of a complete rethink in the control (Ha Ha :D ) philosophy what are they going to do now that they shouldn't already have done in response to the previous very clear warnings offered by the previous upsets.
I am very anti the USA "sue them at every opportunity " mentality, but how will it look in a court of law if & when the total lack of accurate data being displayed & acted on by the FCC's ,that is being suggested as a very likely factor here ,is confirmed to be the case.
Is this really a reasonable scenario to give a normal line crew on a dark and dirty night in the middle of the ocean?
It strikes me that Lindbergh had more useful and accurate data available than these poor guys had at their disposal.

Captain Calamity

27th Jun 2009, 10:16

So it seems the best guess at the moment is that probe icing caused all the ADCs to fail leaving the pilots with degraded flight controls and little instrumentation whilst flying through an area of active CBs at night.

Then, over the days since AF447 several other AC report of probe icing and a similar cascade of failures, fortunately with better outcomes.

I doubt heightened awareness has prompted crews to report these incidents when previously they would have said nothing - such severe systems failure would have made the headlines even before AF447.

So, why the sudden flurry of similar sounding problems - a statistical blip or is there some other factor?

CC

efatnas

27th Jun 2009, 10:19

I'm convinced after reading quite some comments, that the crash's cause was an inexperienced pilot. Three hours into the flight the captain was probably sleeping in the back. The senior FO ran into the WX trap. This storm was a monster. I assume around a level 5. The airplane fell apart in the storm. Nobody can expect to get out of a storm that size in one piece. I think, not being an airbus friend in general, there is no design fault and the huppla is political.
chris

Rananim

27th Jun 2009, 11:24

In 99.9% of all mode confusion occurrences on this and other automated aircraft, "What's it doing now?" is a statement about training and knowledge, not about the aircraft itself.

This sort of statement reminds me of the earlier one along the lines of "17 years of flying-dont you think flaws in the design would have surfaced by now?"

Lies,damn lies and statistics.

No interface??Plane is controlled by pilot with a controlling veto from computer.Computer downgrades/upgrades its controlling veto in 4 different sets of laws depending on system status.Computer is subject to faulty source data but still has controlling vote.Computer casts this controlling vote on a series of very complex voting algorithms which are susceptible to spiking and hysteresis.Pilot can see and feel and think without any programming but doesnt have the controlling veto.
Sounds like an interface,and a screwy one at that.Give the human final authority and give it instantly and easily(simple switch).

BOAC

27th Jun 2009, 11:31

I'm with you on that one. I have looked at the 330 FCC info via the Tech Log thread, and am now CONVINCED the system should be:

Full computer control UNTIL sufficient degredation of inputs etc occurs, then straight to Direct Law - not forgetting along the way to teach pilots to fly.

Too many 'options' I feel otherwise, and a significant danger in not knowing what you have got.

fullforward

27th Jun 2009, 11:42

I liked this one - "It strikes me that Lindbergh had more useful and accurate data available than these poor guys had at their disposal".
Maybe not far away from truth.

BarbiesBoyfriend

27th Jun 2009, 14:09

I can only speak from my own experience of flying in awful turbulence in a Cb.

All I did- after the autos jumped off- was to try and hang onto the attitude.
Couldnt read the ASI (!), but pulled some power off to slow down a bit.

Accepted the vertical speed the Cb gave us, (in our case it was downwards) and just concentrated on the attitude. Wings level, didn't trim, kept the AoA at usual value.

Hung on like crazy and waited for it to stop!

I was so maxxed out flying it was all I could do to put the 'belts' on.

I'll be amazed if these guys did anything else.

At least by having the AP and AT go off on 447, it left them with the power they had and the trim/ attitude they had. No bad thing really.

Their ASIs would no doubt have been 'all over the place' due to the big gusts/ turbulence etc but probably unreadable too. Maybe this is when the speed disagree messages were generated.

The a/c plainly then came apart either without any further input from them, which is quite plausible. Or maybe after some erroneous input from them which is also plausible and quite understandable-an attempt to maintain altitude, for example.

The big Boo-Boo was going in the Cb in the first place. Like I did.:uhoh:

Rob21

27th Jun 2009, 14:18

IMHO, flight computers should be treated like student pilots. Let them fly the a/c, but be able to take over (and quick...). "I've got it" means that the instructor has the controls. Take "partially" the control back is not safe, IMHO.

"Protections" should be part of the pilot's skills, it's up to him (her)to decide if a particular control input will exceed a/c limits, but maybe this particular control input can save the situation.

To have the "I've got it" switch is very important. This (switch) will put the "student computer"back in his place.

Students think they know how to fly. Computers "think" they know how to fly.
Management thinks computers know how to fly, so why "spend" more money in training pilots?

Important point to think about, IMHO, is that computers haven't mastered the "art" of flying yet, and pilots are gradually loosing their skills due to this "money saving" policy (lack of training).

Pilots have less control of their a/c, but their responsibilities are getting bigger every day...

Just a thought...

Rob

lomapaseo

27th Jun 2009, 15:14

post 1

I can only speak from my own experience of flying in awful turbulence in a Cb.

All I did- after the autos jumped off- was to try and hang onto the attitude.
Couldnt read the ASI (!), but pulled some power off to slow down a bit.

Accepted the vertical speed the Cb gave us, (in our case it was downwards) and just concentrated on the attitude. Wings level, didn't trim, kept the AoA at usual value.

Hung on like crazy and waited for it to stop!

I was so maxxed out flying it was all I could do to put the 'belts' on.

I'll be amazed if these guys did anything else.

At least by having the AP and AT go off on 447, it left them with the power they had and the trim/ attitude they had. No bad thing really.

Their ASIs would no doubt have been 'all over the place' due to the big gusts/ turbulence etc but probably unreadable too. Maybe this is when the speed disagree messages were generated.

The a/c plainly then came apart either without any further input from them, which is quite plausible. Or maybe after some erroneous input from them which is also plausible and quite understandable-an attempt to maintain altitude, for example.

post 2

I was kicked by some guys who are still under the impression that today's "Professional Pilots" and todays training are above being overwhelmed in the cockpit to the point the pilot is just trying to manage the stick and throttle and actually perspiring too.

One thing that sticks with me so far is that the pilot comments on this thread seem to have a pretty good idea of what they would have done in the the loss of air-data turbulence scenario.

If my interpretation is correct then this is a pointer for searching for other factors.

BigFootDriver

27th Jun 2009, 16:30

I amazes me that the pilot personality contains so much scepticism and disbelief. Since the beginning of instrument flying, pilots have encounter CB's, told the story of undescribeable turbulence and horror to anyone who would listen, yet most pilots dismiss these tales and blunder out to make the same mistake, frequently with tragic consequences.

I fully expect this type of event will repeat itself forever as long as human pilots fly airplanes, simply due to the personality traits that draw a person to a career of aviation.

Countless pilots have pentrated weak CB's successfully over periods of many years, only to re-enforce their belief that CB's aren't that bad and the horror stories of massive encounters can be dismissed as incidents told by scared wimpy pilots.

Back on the days of flying the airmail, we had pilot killed busting a line of midwestern cold front thunderstorms. He was said to be a great pilot "because he was right side up" when the cb slammed his plane into the mud.

God help any pilot who thinks they can handle a severe CB.

BFD (not wimpy but still scared of CB's since May 12, 1982 )

Dysag

27th Jun 2009, 17:22

I'm hoping for a response from someone who knows Air France, to the following. I'm not making a statement, just asking.

IF (just if) the Capt was not on the flight deck, is there any part of the AFR pilot culture which would make the two folks up front hesitant or reluctant to make a significant deviation (time & fuel implications) around severe weather without the Capt's prior knowledge?

PJ2

27th Jun 2009, 17:50

And short of a complete rethink in the control (Ha Ha ) philosophy what are they going to do now that they shouldn't already have done in response to the previous very clear warnings offered by the previous upsets.
Give the human final authority and give it instantly and easily(simple switch).
I liked this one - "It strikes me that Lindbergh had more useful and accurate data available than these poor guys had at their disposal".
Maybe not far away from truth.
"Protections" should be part of the pilot's skills, it's up to him (her)to decide if a particular control input will exceed a/c limits, but maybe this particular control input can save the situation.
To have the "I've got it" switch is very important. This (switch) will put the "student computer"back in his place.
Students think they know how to fly. Computers "think" they know how to fly.
Management thinks computers know how to fly, so why "spend" more money in training pilots?
Important point to think about, IMHO, is that computers haven't mastered the "art" of flying yet, and pilots are gradually loosing their skills due to this "money saving" policy (lack of training).
Pilots have less control of their a/c, but their responsibilities are getting bigger every day...

I would like to comment on these posts. In doing so please understand that I am not "pointing" (as per the offensive finger-wagging emoticon) but rather I am addressing a common perception about this airplane and it's autoflight system in a way that is intended to be respectful and collegial and educational rather than merely disagreeing.

I suspect (and in a few cases, know) that there are some highly experienced people making these points who have made exceptional contributions to this and many other discussions.That is why I think it is important to attempt once again to make something as clear as possible, recognizing that the human, pyschological phenomena called "prejudice" is very much alive and well in this discussion. There are many here making pre-judgements about the airplane without ever having flown it or even understanding it.

In discussing these I believe that the understandings and explanations are crucial to an understanding of this accident and the only reason I bring these notions up at all is I think we all wish to target our energies.

I think further, that anyone who thinks that "the computers" caused this accident through removing control of the aircraft from the pilot without offering the pilot any alternative except the "Spam in a can" position, (a phrase correctly used by John Glenn to NASA when they were designing the Mercury space capsule) has not flown the Airbus or doesn't understand it or have knowledge of the relevant systems.

Pilots of an Airbus A320/A330/A340 are not relegated to observer status when things go seriously wrong and "the computers won't do what the pilot wants".

What is happening here is "groupthink" - through past prejudices (absence of knowledge but a strong opinion regardless), or through reading comments about "computers" and parroting it back in their own words, everyone has jumped on this bandwagon. It reminds me exactly, of the nature of the discourse on the Habsheim accident where people STILL think that "the computers did it".

Like so many occurrences that happen when in a crowd, this prejudice has become an irrational rallying cry and has achieved a life of it's own without anyone doing any thinking or questioning.

This does not mean that this design, just like any other design, does not have it's compromises and problems. Every aircraft design has and it is trite to say or argue otherwise that "one design is superior to another". The record speaks for itself, and no one...absolutely no one, is casting an eye towards the most advance airliner in existence, the Dreamliner, and saying the same things and it is far, far more automated than any Airbus. Prejudice does this.

If you have read this far and haven't thrown up your arms and dismissed this as just another Airbus apologist's diatribe, you will know and hopefully appreciate that I am making a plea for understanding, not a plea to "accept" the Airbus as a design. If one is to criticize with any credibility at all, one must criticize from knowledge, not blind prejudice, (unless one simply wishes to do so, in which case, there is no dialogue, or learning, possible).

The argument;
All posters quoted are arguing that "the computers" somehow removed control from the pilot. This is not the case and up until 02:14:59Z, that was not indicated in the ACARS messages we have. The ACARS messages indicate that the crew had full control over the aircraft up to the point where the messages stopped.

The crew almost certainly did not have speed or possibly altitude information due to the loss of pitot (and possibly static) probe data which in turn, caused the loss, possibly of all three, of the ADRs computers. This is indicated in the ACARS messages - "NAV ADR DISAGREE" is a relatively serious fault.

The ADIRS are not flight control computers. They are a combined Air Data Computer and Inertial Reference Unit into one computer/control panel. I supplied a schematic of the pitot-static system some time ago to help others understand the inputs to the ADR computer.

The ADIRS have nothing to do with the flight controls. The airplane can be flown under complete pilot control (and was) with all the ADIRUs lost. It would be extremely challenging with a high probability of loss of control if the aircraft entered a large CB.

Loss of the ADR computers is a serious abnormality but it will not automatically result in loss of the aircraft. The QRH Unreliable Airspeed procedures, which are memory items and not a "pull out the checklist" item, provide pitch and power data to keep the aircraft within a nominal speed until recovery or other crew action takes place.

Loss of the IRS's is a far more serious emergency if one is in cloud or is flying at night with no visible horizon. But this is not a flight control computer problem - this is a problem which could occur in any airliner design and not just this one.

In at least four cases now, the processes which were created after the Birgenair and Aeroperu B757 accidents occurred, worked, and saved the aircraft.

Failure of the pitot/static system is not a flight control problem.

With the A330 and A340 design, there are three Primary Flight Control Computers and two Secondary Flight Control computers. The aircraft can be flown, under full control, with the loss of all but one of these flight control computers.

The loss of flight data from the pitot-static system will not render any of these five computers unserviceable. Nor do any computers "make up their mind" or "control the aircraft" beyond the pilot's wishes. That simply does not happen and it is time to set the record straight so that it will be possible to comprehend really happened to this aircraft.

I would offer the view that anyone who has prejudged this aircraft likely will be unable to come to further understanding as to what really happened in this accident and it will be the work of others to determine what really occurred. That is what prejudice does - blind one to 'undesired' knowledge, here, and in other human endeavours as well.

Summary;
- failure of the pitot-static system and, consequently, failure of the ADIRS does not affect the ability of the pilot to fly the aircraft using the sidestick.

- failure of the ADIRS does not by itself lead to loss of pilot controllability of the 330/340.

- Failure of the IRSs can result in loss of the aircraft through absence of attitude information but as any pilot knows, this can occur in any aircraft, (and does, in general aviation all the time when pilots not qualified on instruments fly into cloud).

- The A330/A340 aircraft's five flight control computers would not be disabled by the loss of pitot-static data. Any one of these computers alone, will provide full controllability of the aircraft "directly", (in Direct Law, in short, an ordinary airplane), just like the B777 will when its flight control computers degrade, for whatever reason, the Direct "law", (Boeing doesn't call it a "law"). The "big switch" in the 777 permits the pilot to manually switch to Direct control but control is still electronic and not "cable-and-pulley". I can supply the schematic, if anyone wishes to compare systems).

- The question of loss of all five flight control computers via the loss of all ADIRS input is not answered in the information I have available. However, loss of all five flight control computers, (by whatever reason), results in a heavily degraded controllability through rudder, THS, (Trim Horizontal Stabilizer) and engine thrust; more control than the Sioux City DC10 but not sufficient controllability to withstand entry into a thunderstorm.

My sole intention here is to educate, not to criticize points of view. I know there is a delicate balance in a discussion with other professionals.

I think there are good reasons to base criticism of the 320/330/340 design philosophy upon, but citing notions that "the pilot has no control over the airplane", or that " 'the computers' have taken control" is not a solid, nor informed basis for such criticism.

BOAC;
Full computer control UNTIL sufficient degredation of inputs etc occurs, then straight to Direct Law - not forgetting along the way to teach pilots to fly.
Yes. But that is what the aircraft does anyway which is exactly what the B777 does - same process, slightly different arrangement. In "Direct", both systems are ultimately controlled by computers and wire, not by cables-and-pulleys, but ultimately always under the full control of the pilot in both designs, Airbus and Boeing.

Your remark concerning training is absolutely spot-on. Forces beyond our immediate control but seripticiously with our compliance, have tried to "remove us from the cockpit", so to speak, downplaying experience, training and all else a pilot does, legitimized by the impression that "pilots are expensive". As I said to Will Fraser in agreeing with his views on the hubris of automation, the philosophy engendered by the advent of the first fbw design does have a basis for criticism and I and many of my colleages said so and did so at the time we were being checked out. I recall when the 320 had no such thing as VNAV and we flew it with either "Open Descent", (FlCh for Boeings) or Vertical Speed and nothing else. When the "Full Standard" was introduced, we were handed a 300-page "FMGS Pilots Guide" and told to learn it on the job. No training, no guidance. This was in the days just after the Madras and Strasbourg accidents where mode confusion was still a new thing and no one knew. That was the approach taken and I have to observe that it hasn't changed much in twenty years. I think it is about to.

lomapaseo;
One thing that sticks with me so far is that the pilot comments on this thread seem to have a pretty good idea of what they would have done in the the loss of air-data turbulence scenario.

If my interpretation is correct then this is a pointer for searching for other factors.
Yes. That is one of the reasons I wished to take some time to write this rather longish post. I think looking towards "the computers" for a cause is a rabbit trail; we will not be able to determine what happened by following it.

I sense, (and that's all it is) that this is an extremely complex accident and hope that this is both understood and appreciated by the BEA and all other flight safety organizations.

PJ2

stepwilk

27th Jun 2009, 18:16

"All I did- after the autos jumped off- was to try and hang onto the attitude.
Couldnt read the ASI (!), but pulled some power off to slow down a bit. Accepted the vertical speed the Cb gave us, (in our case it was downwards) and just concentrated on the attitude. Wings level, didn't trim, kept the AoA at usual value."

Well, somebody finally said what I've been wondering for 123 pages of posts. Back in the Dark Ages when I learned to fly (mid-1960s), we were taught that what you did if you flew into Cunim was 1/maintain attitude and wings-level, 2/hold pretty much the power you've got, and 3/ignore altitude. Nobody ever said much about airspeed, which took care of itself if you did 1, 2 and 3.

PJ2

27th Jun 2009, 18:27

stepwilk;

That's classic SOP for inadvertent CB entry and is standard kit for an airline pilot. Perhaps it wasn't discussed because of this, but it's good to see it said. They're essentially the same items as handling an unreliable airspeed indication except a couple of pitch-power memorized items to stabilize the aircraft for troubleshooting.

As has been pointed out here many, many times now - doing both, (failure of all flight data and possibly attitude information while inside a CB), would have a very low possibility of a successful outcome, in any aircraft.

Will Fraser

27th Jun 2009, 19:00

PJ2

You have claimed that I, as a member of the group of 'all other posters', hold that the computers somehow prevented the pilots from controlling the a/c in some way.

My position is exactly the opposite. Given the regime at the beginning of the ACARS, a/p flying, cruise alt, pilots monitoring, etc. I have held that given the parameters allowed the a/p, the flight crew were satisfied with the situation (this is of course assumed). The a/c experiences some turbulence or other challenge the a/p is unable to track, and it trips off.
Following directly its disconnect is entry into Alternate Law. It is at this point things begin to go pear, or so we can entertain, given the messages on the data sheet.

In some as yet unknown sequence, multiple failures are reported, and experienced as warnings, flags, and multiple displays. I would suggest that it appears the PF and PNF were 'startled', first by the disconnect, then by the computers programmed responses such that they were possibly overwhelmed; it is at this juncture that an untrained for and (perhaps) deliberately ignored result may have eliminated any possibility of recovery. As per the other (and recent) unreliable AD incidents show, to recover demands a crew be incredibly sharp, profusely trained, and able to selectively ignore some of the computer's conclusions. On this night it wasn't to be, or so we can propose.

As I have said, the Airbus330 is a phenomenal a/c, no one can deny it. What might be lacking is a recognition of, and training for, some blind spots in programming, and a hard look at the imperfections in the interface between FBW and the pilots. As far as that goes, the only real difference so far making the AB unique is Alternate Law; it is as you say quite possible no a/c could have escaped the fate of 447.

Loss of all pitot/statics has been discussed, it might have caused an overreaction in the software (perhaps not), and an underreaction in the pilots. If this is true, we need to put pilot and FBW back on the same page.

cheers, Will

24victor

27th Jun 2009, 19:32

PJ2;
I think there are good reasons to base criticism of the 320/330/340 design philosophy upon, but citing notions that "the pilot has no control over the airplane", or that " 'the computers' have taken control" is not a solid, nor informed basis for such criticism.

Thoughtful post and thank you for it. The A330/340 series represent the pinnacle of achivement in control automation. Essentially, the design in its entirety is a "system of systems" and this area is still very much a work in progress in all control systems philosophy. It's not the control systems themselves the represent the "problem", as you rightly point out, but the manner in which they interact both between themselves and with the operating crew.

Will (IIRC) brought forward the concept of "supremacy" in terms of the relationship between the operational philosophy of the avionics suite in its complex totality and that of the essentially passive crew, whose operational role is now more of observers, rather than participants, viewing events through myopic PFDs .

Nothing I've read suggests anyone posting here is a Luddite and I believe it's generally accepted that the level of automation will continue to increase, to the benefit of all. ABI are very much at the forefront of this and, rightly or wrongly, will take the flak when the holes line up.

It seems, to me at least, that the industry may have got ahead of itself in using the speed of digital electronics to marry functions which traditionally had little or no direct interdependance without paying sufficient attention to the need for an elegant regression to manual control.

Thanks again.

24V

jcarlosgon

27th Jun 2009, 19:47

stepwilk
Well, somebody finally said what I've been wondering for 123 pages of posts. Back in the Dark Ages when I learned to fly (mid-1960s), we were taught that what you did if you flew into Cunim was 1/maintain attitude and wings-level, 2/hold pretty much the power you've got, and 3/ignore altitude. Nobody ever said much about airspeed, which took care of itself if you did 1, 2 and 3.

That is absolutely true and it will stay that way… but…
It is very difficult to perform step #1 in alternate law, as the “protection” against too low or too high speed – be it erroneous or not, will demand a considerable permanent force on the stick, until the computers, not the pilots, switch to direct law.
Quote, FCOM, my underlining,
PROTECTIONS
Low speed stability
At low speed, a nose down demand is introduced in reference to IAS, instead of angle of attack, and alternate law changes to direct law.
It is available, whatever the slatslflaps configuration, and it is active from about 5 knots up to about 10 knots above the stall warning speed, depending on the aircraft's weight and slatslflaps configuration.
A gentle progressive nose down signal is introduced, which tends to keep the speed from falling below these values. The pilot can override this demand.)

I wish I had a DDL (Directly to Dorect Law) Switch (not a push button).

PJ2

27th Jun 2009, 20:01

24victor;

And thank you. I realize that in saying the things I have, I risk treading on people's views and do not wish to do so simply to disagree and leave. I think it was important to offer clear reasons why I think suggesting a re-focussing or a re-informing of what autoflight is and what it isn't as it relates to this accident and I hope I have done this. I know it won't please everyone.

If all systems are working as intended/designed, the 330/340 types are a dream to fly; the entire autoflight system is nothing short of brilliant, but where we may have issues is in that what we could call the "corpus callosum" ...that intellectual space between a very complex machine and an even more complex human operator.

Thank you for your response.

jeremiahrex

27th Jun 2009, 20:03

As per the other (and recent) unreliable AD incidents show, to recover demands a crew be incredibly sharp, profusely trained, and able to selectively ignore some of the computer's conclusions.

I think this is what is making me confused. The computers conclusions? The computer doesn't produce conclusions. This is as far as I know at least. The pilots interface to the airplane remains the sidestick. Throughout the entire episode, the sidestick remains the only control input. According to one of the published papers on the Airbus systems, the failure of any of the FEP systems should only result in an increase in the pilots workload (which would be equivilant to the pilot operating as he did without any FEP system).

As far as I can see, if FEP starts failing, the pilot just continues steering from the sidestick. S/he just needs to be aware that if you make bad choices for inputs they could damage the aircraft. Is this not right?

ELAC

27th Jun 2009, 20:06

lomapaseo;

Quote:
One thing that sticks with me so far is that the pilot comments on this thread seem to have a pretty good idea of what they would have done in the the loss of air-data turbulence scenario.

If my interpretation is correct then this is a pointer for searching for other factors.

PJ2;

Quote:

Yes. That is one of the reasons I wished to take some time to write this rather longish post. I think looking towards "the computers" for a cause is a rabbit trail; we will not be able to determine what happened by following it.

lomapaseo, PJ2

Thank-you for bringing the discussion back down to earth.

Will Fraser;
Quote:

I proposed early on that the interface between Otto and flying pilots is weak and in an out of balance "command" way. It is too quick and too absolute, seemingly wonderful traits, but deadly under certain circumstances. Pilots are comfortable (too much so) when things go pear and the computers make command decisions that are precipitous, and leave the ultimate pilot out of "the loop".

Imagine flying along fat and happy, and in less time than one can belch, the box cascades decisions and reports to be assimilated immediately with the a/c and its contents at risk!! Dark, turbulent, seven miles up, and the box hands two people two folders of data, to be understood and acted upon whilst the seats under your primitive "cheeks gyro" are telling you you have one half second to input a control.

The previous reports of similar loss of data flow involved less than harrowing conditions, and were successfully escaped; conclusions about those incidents are being debated even now, and you are at ease with the highly possible loss of data, panel, as, etc. to be dumped unceremoniously on the pilots laps???

This interface is the 400 kg gorilla no one seems to be discussing.

Will,

Frankly I'm getting tired of your dramatic, near hystrionic imaginings. Based on your comments you don't really seem to have much of an idea how this airplane actually works or what the situation that presents itself in the cockpit will look like or how it is dealt with by either pilot or aircraft.

I do. And it is nowhere near "the a/c and its contents at risk!!" "in less time than one can belch" scenario you keep trying to conjure. Now, before you come up with some "No, you don't really, you just think that based on sim exercises" type remark, let me state that I really do. This is the result of an event in the real aircraft (in this case an A320) at night in bad weather. My experience was the second (at that time, 14 years ago) ever recorded near-simultaneous dual TAT probe failure on an Airbus family aircraft (later traced to non-common failure modes with an incredibly low probability of occurence). Because it was such a rare experience it was fully investigated by Airbus even to the point of sending update telexes directly to me as the PIC involved.

The incident, which included a very similar set of failures to that which I have seen from the AF ACARS print-out other than the assumed loss of airspeed indication, did not involve the "box cascading decisions" or "two folders of data, to be understood and acted upon whilst the seats under your primitive "cheeks gyro" are telling you you have one half second to input a control." (do you happen to write for the Sun when you're not posting here?).

What did happen was first the loss of AP1, then of AP2 and Auto-thrust. This was followed by reversion to Alternate Law and ECAM messages related to changes and degradations in a number of other sub-systems. This occured while climbing at night through cloud with turbulence somewhere in the mid-twenties. None of the losses as they occurred caused any significant effect on how the aircraft handled, and in that sense the transition from autopilot control to manual control by the pilot was virtually seemless. The number of ECAM messages to be dealt with, though significant, did not cause "cheek gyro clenching panic" or even a great deal of confusion for the crew in terms of how to configure or operate the aircraft. The biggest challenge was that the source failure (a dual one as it turned out) was difficult to correlate to the system failures observed. This turned out to be a result of the failure message for the STBY TAT probe failure not being sufficiently unambiguous to be differentiated from the message for the CAPT TAT probe failure. Hence it was only immediately obvious that one source had failed, not two, which caused a good deal of FCOM investigation as we went along to try and match what we were observing to that which had to have failed.

Shortly after we left our departure airfield it had closed due to weather and likewise the weather had reduced all nearby airfields to CAT II conditions or lower. Given our situation we did not consider a return or diversion for landing in such conditions to be an optimal choice and hence we then flew the airplane (yes, all manual flight at high-altitude) for over an hour across the Rockies to get to a suitable diversion airfield. As the situation evolved, it was the more mundane aspects that proved a bit more challenging, the aircraft handling itself was a complete non-issue. The dual TAT probe failure locked some of the FMGC functions such as flight phase changes, adding a few tricks to how to navigate to our diversion airport and make approach preparations. When we arrived at the diversion airport the approach was conducted hand flown in alternate law with an uneventful landing in direct law once the gear was extended.

The moral of the story, Will, is that the probe faliures that have been described, and which we believe may have occurred to the AF aircraft, do not result in things going immediately and dramatically pear shaped or the aircraft making "command decisions that are precipitous, and leave the ultimate pilot out of "the loop". They are a challenge to deal with, as they would be on any aircraft, but they do not materially affect the controlability or stability of the aircraft. Trying to cast this as "the 400 kg gorilla no one seems to be discussing", is a venture into over-wrought hyperbole at a point where there is no information that supports how a loss of control may have occurred and whether or not it was from forces that would have caused an upset in any aircraft, modern or geriatric.

ELAC

Me Myself

27th Jun 2009, 20:06

IF (just if) the Capt was not on the flight deck, is there any part of the AFR pilot culture which would make the two folks up front hesitant or reluctant to make a significant deviation (time & fuel implications) around severe weather without the Capt's prior knowledge?

Right on the money ! There is and it is mainly due to the differences in reactions from skippers once they discover the aircraft miles away from the track. It's happened to me when I was a F/O and being rather pig headed and a woos, I couldn't care less about what the guy said as long as we were out of the CB's. Not the case for every copilot.
I remember being amazed............and scared as a F/O at how close to yhe CB's some of these older guys would take us. As to the radar which I was adament to use with full gain, it was a constant battle with the captain turning it back to auto telling me " You're going to scare yourself boy. See, it's all green now ". I swear I am not kidding.
Today, I really have to brief the F/O's not to hesitate to deviate as much as it takes..........and I don't always get the results I want.
There is both a lack of training and a lack of awareness. A lot of younger chaps have no clue, or had no clue how dangerous it can be and 447 was a brutal wake up call. Even now, there is a huge denial about the possibility that the crew might have flown into this weather, and this despite all evidence shown by Tim Vasquez.
One thing I can tell you is, a lot of us are going to stay on the flight deck as long as it takes before getting our well deserved r&r's.
My opinion is that, regardless of the talentof the chaps sitting up front, there is a breach in the chain of command. No one is really in charge and in a dire situation like the one 447 encountered, there is no way you can have ONE single person in command who makes the life saving call. This is why the captain has to be in his seat until the situation allows him to take his rest safely.
Not a put down for F/O's, just a hard fact.

Some of the posts here are full of very simple wisdom. Show respect to mother nature and go back to basic. Unfortunatly, keeping attitude and thrust isn't rehearsed in the sim. we're supposed to be happy with what's in the books. Lack of time, lack of money..........etc
I think the system has just gone cookoo.

PJ2

27th Jun 2009, 20:08

As far as I can see, if FEP starts failing, the pilot just continues steering from the sidestick. S/he just needs to be aware that if you make bad choices for inputs they could damage the aircraft. Is this not right?
Yes, that is correct, and the cautions are in the AOM and QRH. Handling the aircraft is completely conventional in Direct Law.

BOAC

27th Jun 2009, 20:22

To bring this back to the thread topic - because of the limit on 3 letter search here I cannot easily find if we established whether the a/c used EPR or N1 on the engines - anyone know? If EPR, is there any way the 'faulty' ADUs could affect the readings?

ELAC

27th Jun 2009, 20:25

BOAC,

The GE engines use N1.

ELAC

FrequentSLF

27th Jun 2009, 20:29

jcarlosgon

Is it correct than in case of dual ADR failure (ADR disagree) the aircraft reverts to alternate law 2 and therefore the low speed stability is lost?

Hyperveloce

27th Jun 2009, 20:30

How can we be sure that all the 3 inertial references (attitude) were faulty/lost ? Does the 02:11Z FLR : 341234 IR2 EFCS1X,IR1,IR3 point toward a triple inertial failure or just that the IR2 has been voted out by IR1 and IR3 ? Has aviation history ever recorded a triple inertial failure ?
In fact, how can we even be sure that one IR actually failed ? Even in the Qantas "NAV IR 1" fault report, the IR part of the ADIRU1 was probably not faulty, the culprit was the ADR1 delivering spiky AoA measures (which were not voted/filtered out by the AP despite multiple "ADR1 fail" indications, even after ADIRU1 was switched off).
Jeff

BOAC

27th Jun 2009, 20:50

Thanks ELAC - that's good news!

I commented a while back on 'crew rest' issues and as a (retired) short-haul w***er [with NO experience of flight-crew 'relief(':))] I expressed the opinion that I would not expect a Captain to 'take his rest' with the ITCZ to cross and 6-7 hours of relative peace to follow. I was somewhat surprised yesterday to hear from a 5 year retired BA 747 trainer friend that in his life the system was very 'rigid' and that rest would be taken 'on schedule'. I had always assumed that as Captain and 'responsible' I would, in that position, have dispatched a co to rest in my rest slot. Certainly with the known 'history' of probe problems in weather I would be pretty certain I would have stayed. Anyone to comment?

Hyperv - I don't think anyone has suggested that? AD failure is all I think we assume although there have been questions over ISIS? As far as we know, I think, it is assumed that IRS systems would be unaffected UNLESS denied by the software.

FrequentSLF - armed with my new knowledge from the Tech forum and with acknowledgement to SmartCockpit, High AoA protection does appear to be lost with dual ADR failure.

NARVAL

27th Jun 2009, 20:58

This is not a comment on the Air France crew, but a remark on the way training in airlines (the one I know anyway) is becoming just a quick dip in the books.I have been retired for five years now, but I believe that not only has there been no strengthening or widening the scope of rating qualification on the big liners, but to the contrary : many necessary enlightments that were given at the time by ground instructors have disappeared…with them. Young pilots, with well-made brains, are trained quickly to an acceptable standard, that means dealing competently with the aircraft faults in the simulator, clearing them, reading the status…Then they fly the A320 with very low flight hours at the beginning, and after a short experience on that remarkable plane (no joke intended, I liked it) they naturally have a tendency to believe that they are airline pilots. The simulator sessions are programmed to deal with what is in the regulations (engine failure, engine fire etc…) and not much else as there is no spare time. Economic pressure all around prevents the Chief Pilots from dealing with the « nice to know ». And when you are on the A330 for example, you might land the plane three times in the month as a copilot, and eventually land it in the simulator to get the necessary « recent experience ». Some fly sailplanes or do aerobatics during their spare time, but they are not the majority, far from it.
I just read a paper by an Airbus Test Pilot (Airplane Upset Recovery) which sums up what he sees as most important, after participating in the very exhaustive and remarkable « Airplane Upset Recovery » (see FAA Airline Operator Training) in which Boeing, Airbus, Flight Safety worked together. What does Captain Wainwright, Chief Test Pilot Airbus, tell us ? The study (which I feel is a need to know for every airline pilot) « is aimed at preventing loss of control on conventional aircraft. It is not aimed at Fly by Wire aircraft. There is no need for this type of continuation training on protected aircraft, although a general knowledge of the principles involved is useful »
I have the utmost respect for Captain Wainwright, and he is of course, himself, fully ready to deal with any upset…but he has apparently no idea of the way this knowledge slowly disappears in some airlines (large ones). This attitude might even be dangerous for Airbus as we can see that there is an evident need to train for such upsets…Well, I may be wrong, but his statement frightens me a little…

DJ77

27th Jun 2009, 22:39

Hyperveloce: I agree with your interpretetion of the message about IR2. A number of people (including me) suspect other problems, beyond the Pitot probes, interfered.

And I disagree about your statement that only the AoA probe was spiky in the QF072 accident. The FDR and The QAR reported spikes from many parameters, mostly air data but also pitch and roll.

The upset only occured because the master PRIM failed to correctly filter the AoA spikes. ATSB found that IR1 was flaged inop first by FMGEC1.

kilomikedelta

27th Jun 2009, 22:45

For Narval and others who have expressed similar opinions, I can empathize with your sentiments as a very similar degradation is occurring in my profession - medicine. Experience (however expressed: gut feeling, seat-of-the-pants, I know, I don't know how, etc), is discounted as being unquantifiable and therefore invalid. I've encountered many situations were health care professionals have responded only to the numbers. Fortunately, I was able to point out that the numbers didn't fit the situation so no harm was done. I've been designing and programming computers since 1964 and practicing medicine since 1978. I still don't trust computers but I do trust my gut. Computers certainly do make life easier but they are not professionals.

wes_wall

28th Jun 2009, 00:17

Why does the question continue to rise relative to what the Captain was doing at the 0214z time frame. Either the crew as assigned was qualified or they were not. Whether the Captain was at rest, or sitting in the left seat should not be a factor. If it was, then AF has some serious problems with its bid lines, and more importantly, its company policy in how it staffs it flights.

lomapaseo

28th Jun 2009, 01:16

The simulator sessions are programmed to deal with what is in the regulations (engine failure, engine fire etc…) and not much else as there is no spare time

An interesting but soft point (little data).

On the one hand I read opinions from pilots who claim to understand and know how to handle loss of air data in turbulence. This seemingly contradicts the claim of inadequate training.

If something is missing in the training we need understand where and how to fix it.

It's probably too early to conclude this without more data including what happened in this accident.

I'm a fan of simulators but having lost arguments in the past about nice-to-have, training we have to face the reality of prioritization and availability of pilots for unique training.

jcarlosgon

28th Jun 2009, 01:55

FrequentSLF

Is it correct than in case of dual ADR failure (ADR disagree) the aircraft reverts to alternate law 2 and therefore the low speed stability is lost?

Yes it is.

protectthehornet

28th Jun 2009, 02:42

if the captain was in back and the other pilots were at the controls and the airline and french authorities deemed them fit for those positions, THEN all was ok.

perhaps, all of us super experienced jet jockeys should think for just a second that: these pilots were as good as we are and maybe something really unexpected happened.

mephisto88

28th Jun 2009, 03:41

Gents,

I have been crossing the recently demonized ITCZ in a 330 anywhere from 4-8 times a month, for quite a number of years.

I've read with much interest over the last few weeks, but refrained from making comment as there were more than enough self opinionated posters willing to display their significant knowledge, or for some, appalling ignorance.

However, on the 'opinions' recently posted about the scenario of the two FO's in control when the accident happened, I feel many posters are being a little harsh on summizing how they may have acted incorrectly.

It makes me realise how blinkered or rigid some people are when you get quotes like:
BOAC I expressed the opinion that I would not expect a Captain to 'take his rest' with the ITCZ to cross and 6-7 hours of relative peace to follow. I was somewhat surprised yesterday to hear from a 5 year retired BA 747 trainer friend that in his life the system was very 'rigid' and that rest would be taken 'on schedule'.
I have frequently taken rest during the 'crossing'. Like all aviation situations, you weigh up the pro's and con's, and take the best of what is often, all the bad choices presented to you. For instance, the weather at destination may require more of your concentration later, than the crossing of the ITCZ now. Consequently, with a competant well briefed and trained crew, there is no great drama in taking rest during that period. That said, if the experience or competancy levels of my particular crew on a given night were suspect, then would I take my rest then, probably not. But am I rigid in when I take my rest, definately not.

Me Myself My opinion is that, regardless of the talent of the chaps sitting up front, there is a breach in the chain of command. No one is really in charge and in a dire situation like the one 447 encountered, there is no way you can have ONE single person in command who makes the life saving call.
Of the gentlemen, (and some ladies), who I leave in charge when I am resting, I am in no doubt that they take on the responsibility fully when I leave the flight deck, and yes ONE person is in charge. I may perhaps sow some seeds of thought concerning terrain or depressurisation aspects, or even perhaps ask that they keep a strategic lateral offset in, when not manouevering around weather, however they know they are in charge, and that they make all the decisions. Again, I have no doubt that the relief commander/pilot in charge would take a similar course of action to what I would do, were I to have been in the seat, because of the next quote:

p51guy
FO's aren't tested to the same level as captains.

I'd hate to work for that airline!
Where I work, the right seat guys are tested to, and expected to perform to, exactly the same standards as the skipper. Most of the crew in the right seat are there because of time in the company, not because of lack of ability. Indeed, many of our crew have the seniority for a command, but opt to stay in the right seat in order to remain on their chosen base.

Maybe I am very lucky to fly with a very professional outfit, and often it comes down to "would I put my wife and kids on a jet if this guy was in command", and when as in most occasions the answer is yes, I may take my rest crossing the ITCZ.

So as far as the AF copilots go, how about giving them a little more credit that some of our rigid minded posters have done.

beamender99

28th Jun 2009, 07:00

Where I work, the right seat guys are tested to, and expected to perform to, exactly the same standards as the skipper. Most of the crew in the right seat are there because of time in the company, not because of lack of ability. Indeed, many of our crew have the seniority for a command, but opt to stay in the right seat in order to remain on their chosen base.

A few years ago I was talking to a very senior FO and when asked what about a command ? His reply was " I will loose so much income as I currently have first choice of routes ( expenses)"
I recall a well known FO on Concorde getting his command on 737s.
I am comfortable that the guy in the right hand seat is up to standard.

BOAC

28th Jun 2009, 07:46

many posters are being a little harsh - not me. I made no such comment and also assume the 'relief crew' to be competent. I was just surprised at what I heard from another airline where, contrary to your post "But am I rigid in when I take my rest, definately not.", they appeared to be, from what I was told.

I repeat - in view of the KNOWN issues with 330 pitot inputs in weather, I reckon I would delay my sheer luxury of 'rest' (based on years of 15+ hours continuous duty with no rest).

NB Nor am I saying that is what happened here. It was an enquiry into an unknown world of 'scheduled rest'.

Me Myself

28th Jun 2009, 08:41

Again, I have no doubt that the relief commander/pilot in charge would take a similar course of action to what I would do, were I to have been in the seat, because of the next quote:

I can only say " Lucky you !!" because from experience, I can tell you it is very uneven. You get some outstanding chaps whereby I sleep like a baby, some others should altogether be out the shop. Plain simple.
It is assumed, all F/O's are of the same caliber ( same applies to Captains ) and we all know it's not the case. There is a huge variety of pilots, ex military, GA and cadets. Sorry, but a 3 years senior cadet who ends up flying the 777 isn't like an air force or navy bloke who's got a 12 years miltary carreer under his belt.
Trust me, I've discovered some pretty interesting things coming back from my break, some of them would just baffle you. My trust is now given on a one to one basis and I have learned to be that way from past bitter experiences.
Second, in the particular 447 case, while on cruise, the acting relief pilot sits in the right hand seat. So far the best way to perform an emergency descent which, until today , has been the worst forseen case scenario. This would mean the acting relief F/O would have had to fly the aircraft from the right seat, in direct law, using the stand by horizon ( assuming it was working ) and in severe turbulence. Who can do that ? I know I can't.
Evidently, the SOP's need to be reassed as the worst case scenario is worse that we thought it could be.
Training needs to be beefed up beyhond the boring engine failure on take off. In the 5 years on the 777, only once have I flown the sim on the stand attitude indicator and only because I had requested it having 10 minutes to spare. The nice to know that can ultimatly save your life has almost disappeared and I remember bitterly what a training captain once told me as I was requesting some out of the ordinary exercise " That's bloody ridiculous. It simply cannot happen " ..........;It was flying with total loss of flight controls.

FrequentSLF

28th Jun 2009, 08:50

I can only say " Lucky you !!" because from experience, I can tell you it is very uneven. You get some outstanding chaps whereby I sleep like a baby, some others should altogether be out the shop. Plain simple.

Just to raise a topic of discussion.
Being the Captain the ultimate responsible for the safety of the flight can he/she refuse to take off with a FO which he/she deem not sufficiently proficient on the type?

FSLF

Dave Gittins

28th Jun 2009, 09:43

Theoretically yes ... but I cannot recall ever having heard it happen.

A37575

28th Jun 2009, 11:06

I'm a fan of simulators but having lost arguments in the past about nice-to-have, training we have to face the reality of prioritization and availability of pilots for unique training

It is more the case that some of those in flight standards chairs are simply out of touch with real life accidents over the years. How many of these people assiduously read accident reports published in various journals such as Flight International, Aviation Week, Business & Commercial Aviation, NTSB and AAIB accident reports and a host of excellent readily available flight safety reading matter?

If they did, then they would surely see the need to be proactive (hate the term, but most people seem to know what it means nowadays) and re-organise simulator training to learn from those accidents. Instead, we see the same old same old of long winded LOFT's where a disproportionate amount of scarce simulator time is spend "managing" a long winded series of unlikely scenarios involving dragging out the MEL, then follows lots of taxiing and a still more long winded take off briefing covering every possible "threat" and how to "manage" the threat.

For Heaven's sake - LOFT occurs every time we get airborne in the real aeroplane. How much more practice do we need in the simulator for LOFT? What a waste of precious simulator time when the more serious things that can kill you are seen as low priority "fun" exercises consigned to the last few minutes of a sim session - if one is lucky.

Obviously jet upset training for example is seen as a waste of time - same as regular practice at limiting crosswind landings on slippery runways which take real handling skill that few new first officers have at this point in their line flying.

Until flight standards people and regulators realise that the lessons learned from past accidents should be applied to simulator training, then pilots will continue to turn up each few months to the same old bog standard engine failures at V1, all automatics flight and general relaxed button pushing - and then just watch whatever real handling skills they may have once had, just slowly disappear in the fog of complacency.

Me Myself

28th Jun 2009, 11:28

Just to raise a topic of discussion.
Being the Captain the ultimate responsible for the safety of the flight can he/she refuse to take off with a FO which he/she deem not sufficiently proficient on the type?

Personal experience :
First assignement I got once ckecked out on the 777 was to sit in the left seat in the sim for a F/O who was just coming back from part time leave if I recall.
Simple enough, it was supposed to take an hour with 3 engine failures between V1 and VR: three times in a row..............we crashed up to the point where the intructor decided it was the sim that wasn't working properly !!!!!! and triggered the engine failure after gear retraction. We barely barely made it and I thought we were in cookoo land.
Sure enough, the F/O was checked and signed and left merry as a lark leaving me with the tought that if I ever see him / her again on my flight, he / she is history. Does that answer the question ?
Question : Why didn't I open my mouth ??? That's the trick, because if you do.............you're toast !!

dougydog

28th Jun 2009, 12:27

Me myself,

You make some very interesting observations in a your posts...many of which I agree with.

Why was AF447 they in that thunderstorm?

Interestly we might learn something from the seafaring industry...P+O have very strict SOPs as to when the skipper or commander must be on the bridge of their cruise ships even though they have watch officers who are very very experiencedWhy? Simply because the buck stops with him. They`ve had 170 years of experience and have learnt from previous accidents/incidents. He must be on the bridge not only going into and out of port(take-off and landing) but for instance in busy shipping lanes like the Channel shipping lanes , anytime in fog, anytime a pilot is on board and difficult navigations like the Dardenelles. Why do you think they have these rules? Airline SOPs for when the Capt is on the `bridge` are limited to take-off and landing but i think you`re right -I treat each F/O on merit and you do have to think carefully about when would be the best time to rest if at all....some more thought will go into this area no-doubt.

HotDog

28th Jun 2009, 12:36

frontrow, the alledged storm encounter occured several hours after takeoff. If the captain had alledgedly retired for his inflight rest, it has been already established that the rest of the operating crew were fully qualified for the safe operation of the flight. Untill such time that a definite cause can be established for this accident, which possibly will never be found if the FDR/CVR data can not be recovered, 2486 posts really do not prove a thing. I have experinced many thousands of hours of Boeing operations safely but would not dismiss the A330's record since it's first flight in 1992 with a total of 616 built so far and I'm willing to await the official report by the authorities of the bodies eminently qualified to provide a factual cause for the accident.

Me Myself

28th Jun 2009, 12:38

[officers who are very very experiencedWhy? Simply because the buck stops with him. /QUOTE]

And this should come in fashion again. No, not everybody is interchangable. No, a 5 years senior F/O is not the same than a 25 years pilot with 15 years of command behind him. We have unfortunatly come to the point where because the F/O CAN fly the plane ( Thank God ) and replace the skipper should this one meet his creator in an untimely way, then he is supposed to be his equal !!! That's total tosh regardless of the ability of the guy sitting in the right hand seat.
When I was a F/O it did look very easy from my seat.
Getting back to P&O, where was the skipper of the Amoco Cadiz when it crashed on the alaskan coast creating the biggest environmental disaster ever ???
Drunk, in his bunk !!

[quote]Why was AF447 they in that thunderstorm?

The question nobody wants to ask or answer, some even claiming these alledged CB's were just a fiction. Then explain me why AF 459 diverted 70 miles off track.
Then comes the aircraft that no matter how great people claim it is, shows some pretty amazing flaws.
Then comes the training : how on earth are we supposed to handle these aircrafts in degraded mode and adverse weather if we don't get the minimum training for it. And please, stop telling us a monkey could do what we do.
Then come SOP's as explained above. How can a pilot fly in direct law from the right hand seat using the stand by horizon. Answer, transfer of control to the guy on the left..............who's never flown the aircraft from that seat, let alone with controls working properly.
No, it is not uncool for the skipper to be in his seat whenever he sees fit. I know, we all have to look and be cool nowadays and turn out to be approval seekers instead.
Then comes management who should do his bloody job and .........er ........yes ....manage instead of burying its head in the sand and pretending everything is honky dory.

madrock

28th Jun 2009, 12:41

Question : Why didn't I open my mouth ??? That's the trick, because if you do.............you're toast !!

Unfortunately based on several recent posts this seems in many ways to reflect the state of the industry. When many of the people who are in positions to know the difference (pilots, engineers, training crews etc..) collectively see a problem but are intimidated by corporate scare tactics the industry is indeed heading into unknown territory. Also prevelant is the notion that things have advanced to the point where many have given up any notion of how to resolve these issues. When training and flight safety programmes are "locked-on" to SOP that may have been intentionally limited there's only one word to describe the collective thought process employed - dangerous.
To reverse it we have to rely on those in positions to know the difference to take the risk and speak out, because if we're waiting for the beancounters.................we're all toast !!

Hyperveloce

28th Jun 2009, 13:07

Hi there
I have just read again the Air Caraïbe report to see how the crew reacted to the cascade of fault reports, subsequent deprievation of flight protections, and how they applied the relevant procedures. There are french speaking people here who can translate any cryptic part of this report in French.
Phase 1 (22:11) "Weather deviation procedure for oceanic controlled airspace" (modification of the flight level, without result, back to initial FL)
Phase 2 (22:22) the "severe turbulence" QRH 5.01 procedure is implemented (A/THR off, N1 between 0.81 and 0.82)
Phase 3 (between 22:22 and 22:23) freezing of the Pitot probes
CAS plunged rapidly from 273 kts to 75 kts
ECAM messages: AUTO FLT AP OFF, MASTER WARNING (cavalry charge), F/CTL ADR DISAGREE, F/CTL ALTN LAW, F/CTL RUD TRV LIM FAULT, etc etc
Between 22:23 and 22:24: STALL, CRICKET and MASTER WARNING
Between 22:23 and 22:24: CAS goes back from 111 kt to 275 kt, ALT from 34200 ft 34500 ft
The crew struggled with the new multiple tasks to implement, and with the application of the QRH "unreliable speed indication": they had not the time to implement the "AFFECTED ADR IDENTIFICATION" and more worrying (I think), the "TECHNICAL RECOMMENDATIONS" in 2.22 state:
"RESPECT STALL WARNING AND DISREGUARD "RISK OF UNDUE STALL WARNING" IF DISPLAYED ON ECAM" and in the 3.02.54 (page 17) of the QRH: RELY ON THE STALL WARNING THAT COULD BE TRIGERRED IN ALTN OR DIRECT LAW. IT IS NOT AFFECTED BY UNRELIABLE SPEEDS BECAUSE IT IS BASED ON ANGLE OF ATTACK"

The Captain was concinced that the STALL ALARMS were irrelevant and took on him to ignore the "RELY ON THE STALL WARNING THAT COULD BE TRIGERRED IN ALTN...."

The Qantas crew was helped by the technical teams on ground to take the good decisions (and they had the time to do so)

I am not a specialist of air safety & procedures, but I feel very weird that fundamental warnings or alarms can have a variable meaning/reliability according to the context, and also very confusing that a crew already struggling with the instruments, not knowing exactly which one is valid, which one is corrupted, also may find ambiguities in the QRH.
Jeff
source: http://www.eurocockpit.com/docs/ACA.pdf

PJ2

28th Jun 2009, 17:51

A37575;
Re, It is more the case that some of those in flight standards chairs are simply out of touch with real life accidents over the years. How many of these people assiduously read accident reports published in various journals such as Flight International, Aviation Week, Business & Commercial Aviation, NTSB and AAIB accident reports and a host of excellent readily available flight safety reading matter?
I think you express the issue very well. Yes, it is a problem and, I think, will become moreso as "SMS" becomes a reality and the regulator steps out of it's monitoring/auditing/enforcing role - another thread. We couldn't even get standards people to look at flight data from their FOQA program; - they certainly weren't spending time reading accident reports to see where the problems lie - a curious thing happens when someone goes into the office - they become a manager focused on costs and they lose "the aviator" in them.

protectthehornet

28th Jun 2009, 18:54

I think you are right. I know that I have seen people in the training department or whatever you call it at your airline that can only do a checkride to FAA standards.

And, let me make this clear, FAA standards are not high enough in my view. Perhaps other regulating authority as well.

I recall when the 737 flipped on its back due to rudder problems...how quickly we got hardover training.

I know what I would do about flying and teaching people to be better pilots.

Hand flying would be a big part of it. Being able to switch from automation to desperation in a second and come out OK.

computers that give us information can be helpful, but computers that rob us of our strengths should be discouraged.

In the USA, near Washington, DC, a computer has been accused of failing and allowing two trains (like subways) to collide, killing 9.

computers, HA.

good thinking A37575

Ialso want to add that people in the training department shouldn 't be there because they play golf with the boss.

testpanel

28th Jun 2009, 19:13

In a post on the very first of june at 21:16 (post nr 243)(other thread) i asked a question about the possibility the capt. was "in the back"

I was shouted at as it was impossible etc etc, what i have seen since is more SPECULATION about that very same thing!

I hope I am wrong...

Me Myself

28th Jun 2009, 19:19

If he was at the back, the 2 F/O were at the front. I often do a walk around just before going to sleep, nothing wrong with that.
However, given the weather that night, taking his break at the worst possible moment would be questionable.
But on the matter, we can only do guesswork. Not helpfull I'm afraid.

Hyperveloce

28th Jun 2009, 19:29

In a post on the very first of june at 21:16 (post nr 243)(other thread) i asked a question about the possibility the capt. was "in the back"

How can we infer this, or why do we need this hypothesis ? Because of two bodies retrieved and latter identified as being the captain and a flight attendant ? Can't we conversely infer that it was the F.A. who was in the vincinity of the flight deck, near the captain on duty ? Or that the F.A. was not in the vincinity of the flight deck but was projected toward it at some point ?
Jeff

jeremiahrex

28th Jun 2009, 19:32

It seems like the popular position to deride both managers and computers.

It is more the case that some of those in flight standards chairs are simply out of touch with real life accidents over the years. How many of these people assiduously read accident reports published in various journals such as Flight International, Aviation Week, Business & Commercial Aviation, NTSB and AAIB accident reports and a host of excellent readily available flight safety reading matter?

I have heard this same speculation leveled at NASA as well. It's pure speculation that honestly doesn't make much sense. If these people were so out of touch then I doubt safety would continue to be as good as it is, statistically speaking. It's still important to remember that these accidents are very exceptional, not every day instances of common failures that the standards authorities are ignoring.

In the USA, near Washington, DC, a computer has been accused of failing and allowing two trains (like subways) to collide, killing 9.

computers, HA.

I have seen accusations leveled at the faulty track sensors. Sensors are not computers. I'd expect a crash if a human operator were struck blind but didn't know it. Wouldn't you? Automation trades human error for computer error. Those that automatically assume humans always make better choices should take a hard look at accident history (current and past, in other fields too) to see that humans have their share of issues too.

Will Fraser

28th Jun 2009, 20:43

jeremiahrex

I may see some of what I would call 'personification' in your post. It is always tempting to put a human shade on what might be called 'stark data'. 'Sensors are not computers'. That's not wrong, nor is 'we trade human errors for computer errors'. If I may I'll use some of your logic to ask a question of another.

ELAC

Histrionics aside, may I ask for clarification on one of your recent posts re: 447, flight computers, and hand flying? With possible corruption of sensors, 330 flight computers seem to produce a reasonably consistent chain of output that may 'confuse', or inhibit manual flying which results as a trip out of the a/p and consequent degradation to Alternate Law or Alternate Law 2. Reference Qantas and NWA, the computer displays 'Stall Stall'. Whether or not that cue is to be taken seriously seems to depend on decisions made by the PF. Do you consider that a hindrance in recovery? Or, could the PF, acting on cue, push the nose down, even add power, though the a/c is anything but stalled?

Also, re: Rudder Travel Limiter. If due to corrupt AS data the ship loses Rudder protection, and possibly all limit to Rudder travel, would you think that a Rudder input might put beyond-fail stress on the VS? To wit, as AS data is lost, could the Rudder Limit reach a status of Low Speed restrictions as determined by the computer? In other words, could the Rudder's travel be deflected enough to convince the sensors in the tail in concert with corrupt a/s that low speed had actually been obtained allowing this deflection to be the new parameter, though the a/c is still travelling at M.80?

Thx
Will

vapilot2004

28th Jun 2009, 21:42

@Will

The rudder travel limiter function was covered earlier, but it was last mentioned scores of posts back over a week ago. Let me share my recollection on the travel limiter.

The A330 will keep limits set at last known good airspeed should there be a loss of air data. If this condition were to be sustained, the system becomes 'unlocked' only upon slat/flap (?) extension IIRC.

Rudder/VS part deux...
Even if the rudder was fully 'unlocked', I see no reason for the PF to touch the rudder pedals at cruise. They don't even make for a good foot rest.

Flyinheavy

28th Jun 2009, 22:27

Reading the CRASH-AERIEN forum of french pilots I found the following post adressing the Antiicing System of the pitots. Reading 400 pages the author shows profound system knowledge and post also relevant schematics. I found it too interesting to not post it here. In the following he talks about the pitot heating logic:

au sol a une temperature relativement faible, je parle de rechauffe en temperature mais j aurais pus parler d augmentation de tension dans la resistance mais bon on fait simple, de l ordre de 25degrés. en vol ce sont les sonde de detection de givrage( ice detect) qui vont en fct de la detection envoyer un signal de rechauffage ou non au calculateur phc (probe heat computer). deux type severe ou non qui modifie ainsi le rechauffage (en gros 200 degres). ces ice detect sont surtout la pour couper le rechaufage quand il n y en a pas besoin. ensuite on a un mode de surpassement en mettant le push button "probe window heat" sur on, la c est pleine power tout le temps (encore faut il le mettre sur on). mais le hic du systeme c est que les sondes ne sont pas situé au meme endroit, deux a gauche captain et stand by (9d1 et 9d3) et une a droite celle du first officer (9d2) avec la prise du vent relatif differente, tout un merdier!!! alors cela ne givre pas au meme moment forcement, c est pourquoi la logique des adrs et qu a partir d une certaine derive d un des circuit les autres le shoot car on ne peut avoir une vitesse differente sur le pfd captain et celui du copi. A relevant foto:

http://www.fotoshack.us/fotos/94282IceDetection.jpg

Translation:

At the ground it is kept to a temperature relatively low, about 25°C, I am talking of temperature in respect of heating, could have talked about increase of voltage in the resistor, but want to keep it simple. Inflight the Ice Detectors will send according to what they sense a signal for heating ON or OFF to the Probe Heater Computer (PHC). There are two modes 'severe' or 'not severe' that modify the heating (roundabout 200°C).
These Ice Detectors are primarily there to switch off heating when it is not required.
There is an override mode, if one pushes the 'Probe Window Heat' button to ON, which will provide constantly full heating (but you have to switch it to ON).
But the problem of this system cosists of the probes not beeing installed at the same location, two at the left side, captain and standby (9d1 and 9d3), and the First Officer's (9d2) one at the right side, with different sensing of the relative airstream, all that beeing a s..:mad:..t!!!
Now this will not necessarily ice up at the very same moment, that's why the logic of the ADRs, as soon as a certain drift of the values of one circuit is sensed, are excluding it, because one cannot have different speeds on captains and copilots PFD.

For me that could be an answer to why the problem with pitot-icing seems to be more prominent on A32/3/40 than other types.

I remember very well that AB pilots at Lufthansa learned a big deal about Ground Sensing Logic after the Warsaw accident, they did not have all details in their Docs before ('...they don't need to know?').
I write this because sometimes there is more behind a system, than would be visibly to us pilots. Having said this, I do not want to imply any bad intention, only thinking that sometimes the 'designer/engineer-pilot interface' has to be looked at more critically.

DozyWannabe

28th Jun 2009, 22:27

I recall when the 737 flipped on its back due to rudder problems...how quickly we got hardover training.
Don't forget that Boeing fought it tooth and nail at the time, and spent a considerable amount of money coming up with a report that tried to shift responsibility to the pilots. It took two accidents with the loss of all on board before Boeing acknowledged there might be a problem.

Or, could the PF, acting on cue, push the nose down, even add power, though the a/c is anything but stalled?"
The opposite happened in two B757 incidents where a pitot blockage caused an overspeed warning, which caused the PF to retard the throttles and stall it, maintaining that action right through the stick shaker. It seems to be a human trait that we lock on to the first problem reported and try to solve that problem even in the face of conflicting evidence. The issue of human/machine interface is one that affects all manufacturers not just of aircraft, but of any complex machinery - especially one that enables something requiring as much safety and redundancy as air travel.

Will Fraser

28th Jun 2009, 23:03

vapilot2004

Points taken. I will point out however, that AB finds it necessary to restrict Rudder deflection, 6 degrees at >350knots. Someone thinks it's important, though it is indeed a poor foot rest. Boeing cues 'Rudder with Caution' when unprotected. With a fully powered Rudder and no mechanical defeat beyond 3 degrees at high mach, well you see the problem. On a dynamic FD, it may at some point be necessary to Rudder, and inputs could possibly be non scalable due to movement of the cockpit.
Without feedback or instruments, one is left with?? No cues to gauge control?

HarryMann

28th Jun 2009, 23:11

It seems to be a human trait that we lock on to the first problem reported and try to solve that problem even in the face of conflicting evidence.

Classic and well documented behaviour, pointed at by the Investigation into the 100 mile glide dead-stick A330 fuel-leak incident, amongst others...

On a dynamic FD, it may at some point be necessary to Rudder, and inputs could possibly be non scalable due to movement of the cockpit. Without feedback or instruments, one is left with?? No cues to gauge control?

... and an old turn & slip BF instrument would be helpful at that point?

Only asking...

DozyWannabe

28th Jun 2009, 23:14

Will, the point is you're really not supposed to use the rudder in cruise in the first place.

Bleve

29th Jun 2009, 00:31

We must protect the aircraft and it's passengers from pilot-error through clever automation.

So goes the aircraft current design philosophy. But of course this will never stop HUMAN-error. All it does is shift the primary cause of errors away from pilots towards engineers. Is it possible for engineers to write software that covers all possible airborne contingencies? Who is better placed to recover the aircraft safely when (not if) it all goes pear-shaped?

There has to be a balance between automation and allowing the pilot to have full manual control of the aircraft when he needs to. I don't think when have that balance at the moment. And of course the pilot needs to have the skills, training and tools to manually fly the aircraft on 'dark and stormy' nights.

Clear_Prop

29th Jun 2009, 01:36

:=

Can I just bring the point home that there is nothing that can be deduced about the on-board position, integrity or activities of the Captain, or for that matter the FA at this stage. After some 3000 posts its saddening to see the degree to which imaginations start to override fact. At the moment all we know is that these poor souls were found dead in the sea a considerable time after and considerable distance away from the incident. We dont know anything else.

I dont mean to have a go, some great analysis going on in this thread, but let's not start writing anyone's obituaries just yet.

Respect.

HarryMann

29th Jun 2009, 01:41

...as we are inevitably going down that road anyway, nobody seems to have asked these questions.

Where would the c.g. be at that point of the cruise, if left to it's own devices?
What is the effect on pitch controllability when reverting to Alt2 or Direct mode of the above c.g. - from the pilot's perspective?

Ditto yaw stability?

4krew

29th Jun 2009, 05:49

willfrazer:
"The tail 'trim' tank would probably be full, to achieve better fuel economy.
The handling would of course be affected in Pitch and Yaw to some extent"

CG would, very likely, be at 38% of MAC in cruise, however up to now I do not know if during the fight certification tests they relay stall this very airplane either in normal forward CG or never at all and use computer accepted stall limits and from there on wards. As per the FCTM A330-340 it is implied that there is NOT a Stall Speed, but this is my perception of the words on the book.

An event on a MD-11 with aft CG that was caught by severe turb in cruise lost some 15,000 feet during a FLAT stall as the airplane recovered the pitch control as the air got thicker during the descent and the elevator responded after thousands of feet lost. It is not the same acft nor the same company as we all know but it comes to my mind if the aft critical CG for saving fuel can also kill.

I know flight certification is costly as they fly some zillion hours before the passengers embark but much of what is on the manual is computer derived.

vapilot2004

29th Jun 2009, 06:32

Will

One correction, the A330 limits rudder travel to 4 degrees above 350 CAS. If I am incorrect, someone please say so. I am not rated on type.

To your point of protections being offered, I agree there is an understanding that the rudder could be needed at cruising speeds and there is reason for limitations, but the cases for this need are rare cases indeed.

Yaw dampers take on most of the task of yaw control at cruise. When these units go offline, it is best not to try to even out a yaw oscillation since one will almost always be behind the curve.

The only other time I would think the use of that control surface is called for at speed would be during an unusual attitude recovery maneuver. In this case, travel limiters or force feedback systems are there more to prevent dangerous pilot-induced yaw than to protect the vertical stabilizer.

quaeler

29th Jun 2009, 06:44

Can I just bring the point home that there is nothing that can be deduced about the on-board position, integrity or activities of the Captain, or for that matter the FA at this stage.

Snotty finger waving emoticon aside, and not to put a too ghoulish point on this, but is there one documented case anywhere that someone can cite in which a belted in left-seater or right-seater was found identifiable, not in the seat, after a large airliner crash?

Will Fraser

29th Jun 2009, 06:46

vapilot2004

PJ2 quoted P,R,Y limits a/p; ELAC quoted 3 Degrees deflection per side; I had thought 4 as well, I believe 6 total is correct.

I agree with all you say; this is not a standard event. At some point from stable cruise to bits in the Ocean there is wide latitude for conjecture. Something caused the VS to separate rather cleanly from the Fuselage. It may be more apparent the sequence/event after the briefing July 2. I won't exclude that the deflection seen on the Rudder at discovery and recovery is not the deflection that caused the separation, iow, full deflection to starboard. It took massive hydraulic power to put it there, and at sever, with no hydraulics or command to return it to neutral (or other), it may be there just as it was. The damage to the bottom of the Rudder may have been air induced, that portion, in the airflow, would be taking the brunt of the air.

Aside, We haven't addressed the engines yet, any water event that could damage all three pitots/statics could cause loss of power in one or both powerplants. If only one, there is a use for Rudder correction as well.

PJ2

29th Jun 2009, 06:52

HarryMann;
Where would the c.g. be at that point of the cruise, if left to it's own devices?
What is the effect on pitch controllability when reverting to Alt2 or Direct mode of the above c.g. - from the pilot's perspective?
Representative cg fore-aft limits would be 17% to 39% MAC. At 210k kg, the cg would nominally be 29% to 33%...slightly aft; the tail would have about 4500kg of fuel at that point.

Pitch control in alternate law 2 (which is what they would have been in) is load factor demand law similar to normal law. Yaw remains in alternate law. They would have been in Roll direct law, which can achieve a roll rate of about 25deg/sec. In smooth air, the aircraft would be very controllable, in other words.

In very turbulent air and certainly in any inadvertent entry into a cell, my sense is, one would have to mindful of large control inputs, above all trying to maintain a level pitch attitude, letting the altitude and even the speed wander rather than chasing it with power (and certainly not pitch) but respecting the stall speed. In extreme conditions, an overspeed is not as serious as a stall - even a 50kt+ overspeed when the choices are really limited.

The weight of the fuel in the wings is actually a slight bonus, helping to reduce the bending moment. The outboard tanks are burnt at the end of the flight.

Settling the rudder limiter question:

RUDDER TRAVEL LIMIT AND PTLU
Rudder and pedal deflection is limited as a function of the speed.

Each channel of the limiter is controlled and monitored by its associated SEC.

In case of double SEC failure the max rudder deflection remains at the value reached before failure then max deflection is available when the slats are extended.

http://i277.photobucket.com/albums/kk76/batcave777/RudderLimiterdegrees2009-06-29_0008.jpg

Will;
Rudder at discovery and recovery is not the deflection that caused the separation, iow, full deflection to starboard. It took massive hydraulic power to put it there, and at sever, with no hydraulics or command to return it to neutral (or other), it may be there just as it was.
Help me out - trying to understand the two statements - "Rudder at discovery and recovery is not the deflection that caused the separation" and then, "it took massive hydraulic power to put it there" - put it where?..at the position we see it in now or at the moment of failure?
Right now, the rudder would be free to move and it's position is a function of the recovery operation. I suspect the damage on the bottom of the elevator is mechanical, not high-speed air-induced.

vapilot2004

29th Jun 2009, 06:57

Will:

I'm in as much doubt as you on the limitation figures. I will go with the experts on the A330. **

**PJ2 has kindly provided us with an edited response after a mere 31 minutes of this reply - thus my own edit. Graphics have been added and more info. Thank you P.

Engine out - good point there. The yaw dampers would attempt to take care of the initial asymmetrical thrust moments and after a manual application, trim would take over from there. At cruising speeds, the deflection angles would indeed be small and I was caught out on that one. Good find and correction of my points offered.

A bit late here and I am in no condition to be at the helm of a car let alone a yoke or sidestick on an airplane. :\

rubik101

29th Jun 2009, 07:40

Notwithstanding the outcome of any definitive conclusion, if there ever is one in this instance, the questions raised about the degree of automation and slavish adherence to same have been well reasoned and enlightening. As the Boeing aircraft become seemingly weekly more like the equivalent Airbus product (Cat II, Single engined 30 flap Auto-landings now possible on B737 NG) it seems to me that the training philosophy will go the same way for Boeing as it currently is for AI.

Mention of the apparent waste of time spent on LOFT exercises and the fixation on that apparent, 'worst case scenario' of an engine failure just after V1 has me nodding my head in agreement. There are several instances which can lead to the loss of an aircraft if a catastrophic event occurs, as shown by the posts here in this thread.

Some very simple faults have led to devestating crashes, as mentioned here, the Tristar in the Everglades and so on. If we can destroy an aircraft when a light bulb blows then how much more likely is it that we will lose one when the Flight Instruments suffer a total failure or we are overwhelmed by contradictory messages and signals from the ever more complex computers on board?

Time spent starting engines, manually closing start valves, taxying, climbing to FL 150 with a Hydraulic failure in the climb followed by a call from Ops to say we have a bomb on board so please return to base asap does nothing to enhance the pilot's ability to fly the aircraft. All of these events can be covered on a line check, and should be from today onwards. Training Captains of the world, unite and demand that sims be used for something useful, not the present folly and waste bent on ticking boxes determined by some retired pilot working for the various Ministires and Aviation Authorities.

Simulator time should be exclusively set aside for the very scenarios mentioned in this thread. These are the events which are killing people, not B or Yellow Hydraulic system failures or passengers with make believe heart attacks.

High altitude upset, stall recovery, unusual attitude recovery, total loss of Flight Instruments and /or total loss of Nav guidance/IRSs, flight with total loss of electrics and so on should be our first priority, however unlikely they might be according to the statisticians. I am sure this list is far from exhaustive, please add to it as you think fit.

The statisticians don't fly the aircraft, we do.

Btw, how many times has a modern engine failed a few knots after V1?

Milt

29th Jun 2009, 07:52

Pitot Icing

Seems we have a recurring problem with some pitots at high altitude when penetrating the tops of CBs. That problem could well be that when we are penetrating CiroCu/CiroStratus rich in ice crystals at way sub zero OATs we may be converting some of those crystals to water with a heated probe. I would expect that some ice crystals will enter the heated pitot simply because of their inertia.The melted crystals may then be entering the tubing connecting the pitot and refreezing to form a blockage particularly if the drain holes of the pitots are too small or already blocked or partially blocked with crystals.

As a TP I have not had any experience in the flight testing of pitot systems except to determine position errors PEs for pitot static systems. These tests are usually done at as close to sea level as possible and more often are done using a trailing static and a test pitot on a projecting boom.

Does anyone know whether the offending pitots and attendant tubings have been adequately tested under the worst conditions to be expected at high altitude.

oversteer

29th Jun 2009, 08:39

a quick q on stalls in jet aircraft;
other than the stick-shaker, do you get any similar clues to being close to stall as you do in a light aircraft; eg loss of authority, vibration, quietness; I am assuming the control setup and cockpit/engine noise mask all these clues, but just curious.

Airbus Girl

29th Jun 2009, 09:03

This is a long thread!

If a pitot breaks off completely it can generate a stall warning. In poor visibility/ thunderstorm/ night it could cause the instant stall recovery actions. Couple this with the incorrect speed readout and this could cause things to go wrong quite quickly.

Simulator training (recurrent). I completely agree that most companies have this honed to the core these days, with just the standard OPC/LPC items covered plus other "scenarios" which often times are unrealistic, to get the "ticks in the boxes". However, this is changing. In future it will be possible to have much more crew specific training - so if for example, you feel you have a weak area, or it is shown in your training file, training will be targetted towards improving that area of knowledge/ skill. This is a huge leap forward and hopefully most airlines will be using this system soon.

I don't agree with all the comments going on about how Airbus is this giant computer that can over-ride a pilot. Yes its systems are complex but it has probably saved plenty of lives too. I think most Airbus pilots are very respectful of the complexity and get it. Boeings can and have crashed due to errors of the crew, for example, thinking the autothrust is in when its not, and stalling the aircraft. Now and Airbus wouldn't let you do that.... So to say all Airbuses are rubbish because they have protections and all Boeings are great because they don't have the same level of protections is rather too simplistic.

ELAC

29th Jun 2009, 09:49

Quote: Will Fraser

Histrionics aside, may I ask for clarification on one of your recent posts re: 447, flight computers, and hand flying? With possible corruption of sensors, 330 flight computers seem to produce a reasonably consistent chain of output that may 'confuse', or inhibit manual flying which results as a trip out of the a/p and consequent degradation to Alternate Law or Alternate Law 2. Reference Qantas and NWA, the computer displays 'Stall Stall'. Whether or not that cue is to be taken seriously seems to depend on decisions made by the PF. Do you consider that a hindrance in recovery? Or, could the PF, acting on cue, push the nose down, even add power, though the a/c is anything but stalled?

Will,

When a failure of an element of the flight control system occurs or data from a source becomes unreliable most of the "consistent chain of output" is intended to, and for the most part does, reduce rather create confusion or inhibit manual flying of the aircraft. The basic purpose of a reversion to Alternate Law and if necessary (the two are not always coincident) the disconnection of the autopilot is to simplify the pilot's means of controlling the aircraft by removing the autopilot and/or some of the more refined protections of Normal Law that might be adversely affected by the failure while the crew ascertains the source of the problem and configues the systems to best minimize the effect.

Some failures by their nature create greater problems than others. In any airplane a loss of valid airspeed or angle of attack data creates the potential for spurious stall warnings as have been recorded in the QANTAS, Air Caraibes and NW reports. This does carry with it the potential for some confusion, and it's precisely for that reason that diagnosis of validity and flight control response to such warnings following such a corruption of data are handed back to the pilot. In all the instances that I'm aware of with Airbus aircraft the crew was able to effectively determine whether the warning was valid and maintain positive control of the aircraft. This is what you would expect from a competent crew. In simple terms, if one moment you are flying along "fat, dumb & happy" and the next your airspeed starts to rapidly fluctuate or becomes grossly inaccurate without equivalent changes in pitch and power, it's a reasonable diagnosis that a stall warning occuring at the same time should not be considered valid unless other basic aircraft parameters have undergone very significant change. So, yes an invalid stall warning can be a source of some confusion which the crew needs to resolve, but no, it should not be a serious hinderance to maintaining basic aircraft stability as long fundamentals such as attitude, power, and trim are observed and managed by the pilot.

Also, re: Rudder Travel Limiter. If due to corrupt AS data the ship loses Rudder protection, and possibly all limit to Rudder travel, would you think that a Rudder input might put beyond-fail stress on the VS? To wit, as AS data is lost, could the Rudder Limit reach a status of Low Speed restrictions as determined by the computer? In other words, could the Rudder's travel be deflected enough to convince the sensors in the tail in concert with corrupt a/s that low speed had actually been obtained allowing this deflection to be the new parameter, though the a/c is still travelling at M.80?

Actually, as has been pointed out here several times in discussions regarding AA587 it is possible to create stresses beyond the designed limits even with the Rudder Travel Limiter fully functioning, so yes it's certainly possible for this to occur with RTL failed regardless of the deflection limit at the time of failure.

I think the question your driving at is: Since the RTL system on the A330 autmatically freezes the maximum rudder deflection value based on airspeed at time of failure is it possilbe for it to be conned into setting an erroneous max. deflection value prior to failure if the airspeed information becomes inaccurate? The simple answer is that I don't know for sure. The more refined answer is that such a situation, if it is possible at all, would have to be considered extremely remote. For it to occur there would have to be not just a simultaneous failure of the three different airspeed inputs, but those failures would have to occur at near identical rates and yet still allow the measured airspeed values to remain sufficiently consistent with the other air data inputs so as to not cause a diagnosed failure of each affected ADR. Any substantial differentials between the airspeeds or failures of the ADRs would cause the system to consider itself failed and lock the max. rudder deflection value at that point.

Even then, based on my experience with the aircraft I suspect that the designers may have considered such a case and included a test for it in the limiter's logic. Though I'm sure there are some very remote failure cases that likely haven't been considered, I think many here with a layman's or even a pilot's general understanding of the flight control systems fail to give sufficent credit to the designers/engineers for the degree to which they have gone to try and analyze and account for each possible failure mode. It doesn't make the system perfect, but it is a lot more so than you'd judge from the theories you are reading here, and in most cases it is a significant improvement on the previous generation's accepted standards of safety (i.e. no limit freeze function, just a warning to use rudder with care).

Quote: Will Fraser

PJ2 quoted P,R,Y limits a/p; ELAC quoted 3 Degrees deflection per side; I had thought 4 as well, I believe 6 total is correct.

This is not correct. My statement to you in response to your question was:

That value is dependent on speed, which according to my manuals at M.80 and FL350 (272 KIAS) is approx. 6 degrees (not 8).

You had stated 8 degrees of deflection which was incorrect. I referred to the same chart that PJ2 has recently posted and provided you with the figure corresponding to M.80 at FL350. You can make your own estimate if you like. If the aircraft's speed had been reduced to 260 KIAS (the turbulent air penetration speed below transition) then the limit might have been slightly, but not significantly, higher.

ELAC

HarryMann

29th Jun 2009, 09:59

Subject to a somewhat aft c.g then (33%) with a/p and a/t OUT..

....one would have to mindful of large control inputs, above all trying to maintain a level pitch attitude, letting the altitude and even the speed wander rather than chasing it with power (and certainly not pitch) but respecting the stall speed.

Thanks! We have heard that the yaw damper is a low-level system that almost certainly would still be functional.
It sounds then that the native phugoid pitch damping is either an a/p function or supplied by Normal (and Alt1?) law.

I'd really like to get at this if I may; what altitude and airspeed range does the A330 (or similar) exhibit if manually trimmed to say FL350 and left to its own devices, at those sort of weights with a somewhat aft c.g. - as I'm presuming it would with a/p OUT and Alt or Direct Law.

Svarin

29th Jun 2009, 10:00

Quote:
emu787:
did the AFCS detect low speed - about to get a stall or low speed buffet boundary approaching (erroneous airspeed information) and the computer pitched the aircraft nose down and applied full power thinking this is the way to recover. This would almost certainly result in instantaneous excessive speed that would test the integrity of the airframe to its limit.

takata
It seems very improbable considering A/THR and AP OFF => Alternate Law2 (protection lost) due to unreliable Air Data (ADR disagree). Moreover, Air France ADIRUs (Honeywell) are different from Quanta's (Northrop-Grumman).

S~
Olivierto Takata :

How do you know the aircraft was actually aware of ADR DISAGREE at 0210Z ? The sequence of ACARS messages says NAV ADR DISAGREE (which sounds somehow something else than F/CTL ADR DISAGREE ?) at 0212Z, giving us a full minute at least between A/P OFF A/THR OFF and your proposed going into ALTN LAW 2.

I would rather suggest that the aircraft was, at 0210Z, just after AP disconnect, in ALTN LAW 1, not yet aware of ADR DISAGREE condition.

Which would mean that Low Speed Protection was active. Precisely, while the pilots were thinking "we're hand flying now", the aircraft applied "gentle progressive nose down input" without any kind of warning other than... STALL STALL STALL... Interesting ?

Anyone could disprove this, and do not hesitate to go very technical.

Wilbur60

29th Jun 2009, 10:01

I can tell you from inside AFR that 'cultural' issues would indeed lead to opposite behaviours,like 2 FO's initiating a diversion without waking the commander in the bunk..(yes,it's been done already..:rolleyes:)
Cheers

Wil

vapilot2004

29th Jun 2009, 10:17

The rudder travel limits per the chart posted last page are for excursions in each direction starting at center. So at 350kts, the A330 rudder, as limited by the flight control software will be restrained to a 4 degree deflection. While not a typical figure of discussion, the total deflection arc is then equal to 8 degrees.

sleepypilot

29th Jun 2009, 10:39

Culture

--------------------------------------------------------------------------------
I can tell you from inside AFR that 'cultural' issues would indeed lead to opposite behaviours,like 2 FO's initiating a diversion without waking the commander in the bunk..(yes,it's been done already..)
Cheers

Well when I'm resting I certainly do not expect a bunk call asking for a permission to deviate for weather.
There are 2 competent F/O's in front, you've briefed them, I would expect a call only for a major problem i.e. tech, medical. Not for weather deviations, even crossing the equator.
If you dont trust the other guys or you feel unconfortable when turbulence starts, just stay in the cockpit.

Lemurian

29th Jun 2009, 10:59

Svarin :
How do you know the aircraft was actually aware of ADR DISAGREE at 0210Z ? The sequence of ACARS messages says NAV ADR DISAGREE (which sounds somehow something else than F/CTL ADR DISAGREE ?) at 0212Z, giving us a full minute at least between A/P OFF A/THR OFF and your proposed going into ALTN LAW 2.
Takata is right.
You don't take a "WRN" message, coming straight from the flight warning computer to the CMC then the ATSU with the same degree of urgency as the "FLR" message which is an advisory to the maintenance department.
Look again at the reversion page already posted several times on this forum and see that , pertinent here, the condition for an auto pilot disconnect is a dual ADR fault and the reversion is to ALTN 2 PROT LOST.

emu787:
did the AFCS detect low speed - about to get a stall or low speed buffet boundary approaching (erroneous airspeed information) and the computer pitched the aircraft nose down and applied full power thinking this is the way to recover. This would almost certainly result in instantaneous excessive speed that would test the integrity of the airframe to its limit.

Nice try. You just forgot that the autothrust had disengaged, too and if anything, we have here a thrust lock. You need another theory.

Lemurian

29th Jun 2009, 13:12

ttcse,
WillFrasier
Quote:
I won't exclude that the deflection seen on the Rudder at discovery and recovery is not the deflection that caused the separation, iow, full deflection to starboard. It took massive hydraulic power to put it there, and at sever, with no hydraulics or command to return it to neutral (or other), it may be there just as it was. The damage to the bottom of the Rudder may have been air induced, that portion, in the airflow, would be taking the brunt of the air.
and

And you should've also noticed that in at least one photo of the fin for AF447 while it was on the ship, the rudder was much more deflected than when the fin lay on the surface of the ocean(tell him Graybeard). Required 'massive hydraulic power ' ??
Pictures better than words :

http://i635.photobucket.com/albums/uu79/DorianBanks/ALeqM5j1xBsIBtlIbTK0uaJ3M08LZZvI0Qs.jpg
http://i635.photobucket.com/albums/uu79/DorianBanks/f42_b.jpg

ClippedCub

29th Jun 2009, 13:18

The rudder is overbalanced. Trailing edge will point up regardless of side of rest. The focus on rudder deflection would be better spent elsewhere.

PPRuNe Pop

29th Jun 2009, 13:29

A polite reminder - this time - to STAY on topic, meandering this way and that will get deleted.

safetypee

29th Jun 2009, 14:01

Milt, I do not know if the specific pitot head has been tested in the relevant icing conditions (#2511).
Some pitot heads, OAT, and TAT probes have been assessed in icing tunnels, and all installed systems should have been exposed to conventional icing during aircraft type certification.

There appears to be many facets to the problem of pitot icing in this instance; first it is not conventional icing.
The atmospheric conditions and likely mechanism of icing (as you describe) are discussed in http://www.pprune.org/tech-log/376345-air-france-a330-accident-6.html#post5027449 and the linked paper "The Ice Particle Threat to Engines in Flight".
There does not appear to be any industry standard against which a pitot could be tested in these specific conditions. Furthermore, in addition to the possibility that every design of pitot head will produce different results, so too could each location on differing aircraft types.
Ice particle induced icing appears to be greatly affected by the airflow characteristics prior to the probe – very small particles probably follow the airflow, but larger ones (and water drops) might cross the flow due to their higher mass.

Fortunately the conditions are rare, or that pilot’s previous avoidance of large Cbs has contributed to infrequent hazardous encounters. Changes in these aspects appear central to recent incidents and this accident – so what is different? The training and use of weather radar has been discussed elsewhere, as has pilot knowledge, attitudes, and behaviour. These probably have contributed, but in previous incidents the outcomes were significantly different and thus the range differing piloting standards should not have been a critical factor in this accident.

The above also appears to support the view that the loss of all pitot information is no greater risk that hazardous – Instrument External Probes (www.sae.org/events/icing/presentations/2007s30duvivier.pdf), and that the aircraft can be flow relatively safely for an appropriate period (average exposure to the conditions 5nm, max 135 nm - engine ref above). However, there may be ‘hidden’ assumptions about crew competence in severe atmospheric conditions, checklist design and use, lack of primary inst, aircraft condition, lack of radar, etc, – what should the safety requirements consider for an extreme adverse combination of factors?
Other certification standards define an adequate level of structural strength for inadvertent flight in severe weather. If (IF) the aircraft broke up in flight then at this time we do not know why, nor apparently do we understand any mechanism for such a failure – we must wait and see.
Meanwhile avoidance of large storms by a wide margin would be a prudent safety action.

Hyperveloce

29th Jun 2009, 14:41

to Takata :

How do you know the aircraft was actually aware of ADR DISAGREE at 0210Z ? The sequence of ACARS messages says NAV ADR DISAGREE (which sounds somehow something else than F/CTL ADR DISAGREE ?) at 0212Z, giving us a full minute at least between A/P OFF A/THR OFF and your proposed going into ALTN LAW 2.

I would rather suggest that the aircraft was, at 0210Z, just after AP disconnect, in ALTN LAW 1, not yet aware of ADR DISAGREE condition.

The ADR DISAGREEment is time stamped 02:12Z (with the uncertainty associated to ACARS time stamping). If two ADR are reported in disagreement, this imply that one ADR had already been voted out (but it was not reported as faulty like in an NAV ADR FAULT) ? The switching to ALTN LAW is time stamped 02:10Z, so you suggest that they were in ALTN LAW 1 and not ALTN LAW 2. This seems logical to me too.

Which would mean that Low Speed Protection was active. Precisely, while the pilots were thinking "we're hand flying now", the aircraft applied "gentle progressive nose down input" without any kind of warning other than... STALL STALL STALL... Interesting ?

Anyone could disprove this, and do not hesitate to go very technical.

In ALTN LAW 1, the LOW SPEED STABILITY protection is still active (pitch in direct law) so if the AP monitor a CAS that is close to/under the stall speed (in the Air Caraïbe case, the CAS plunged from 273 to 75 kts), it can order a "gentle progressive nose down input" to regain a margin versus the stall speed, an order which can be overriden.
Is it possible to simulate or compute the evolution of the (real) airspeed from that event ? (for example using the Air Caraïbe observed biases or the airspeed).
It also raises the reaction of the crew. Did they start to apply the procedure about "unreliable airspeeds" from 02:10Z ? if so did they believed to the instruction that says to "rely on the stall warning that may be triggered in ALTN or direct law because it is not affected by unreliable airspeeds but based on the AoA " ? (and let AP (re)gain speed leading to overspeed). Which part of their attention did they devote to control the aircraft, to try to understand what was the problem with their NAV and instruments & to apply the procedure ? Did they try to restart PRIM1 to regain the normal law during the first 3mn from 02:10Z ? Did they let a critical overspeed situation to unfold and exited the flight enveloppe this way ? (in the very center of a cluster of Cb). Under this scenario, the upper range of allowed airspeeds should have been exceeded rapidly after the initiation of the Low Speed Stability protection ? Is it a matter of 20 s, 30 s, one minute if the pilots let the AP do ? Would it mean that at 02:11Z or 02:12Z max, the aircraft was already in a critical overspeed ? If we have at least 2 mn of ACARS/flight left, would it mean that the overspeed was somewhat contained ?
After the ADR disagreement, they were in ALTN 2 with a very limited protection for their control surfaces (if the AP reads 75 kts instead of 275 kts like for Air Caraïbe, the rudder can be allowed 31.6° instead of ~7° max on the graph given by PJ12). If the VS was lost in mid air, the things must have unfolded very quickly from then.
Jeff