Airbus prepares safety warnings following A321 incident

[aiman]

BBC reporting as follows:
Airbus is drafting a worldwide safety warning about electrical problems on some of its aircraft.

The company is investigating a fault that temporarily affected primary cockpit displays and computer controls on a BMI flight from Khartoum to Beirut in August.

The standby instruments on the A321 plane did operate normally.

The pilots eventually regained control of the aircraft - but by that time it was 20 miles off its course.

The pilots reported that without warning the aircraft began to shudder, banking steeply on its own - failing to respond to pilot commands over a period of several minutes.

The twin-engined jet with 49 people aboard was cruising at 36,000ft.

The crew said they were bombarded by a stream of warning messages before cockpit screens turned grey and then went blank.

The aircraft's left wing suddenly dropped without any input from the crew.

For years, safety investigators have been concerned about electrical system glitches resulting in dangerous shutdowns of flight control computers.

But such incidents are hard to understand and replicate. Airbus says it is helping both the Air Accident Investigation Branch (AAIB) and the BEA in France with the inquiry.

But it has been reported that investigators have already urged Airbus to alert all operators of its A319, A320 and A321 planes about the potential hazards stemming from such electrical faults.

[TheWanderer]

AVHerald reports an A321, G-MEDJ of BMI, flight BD996, went out of control after having electrical problems with its generator #1: Report: BMI A321 over northern Sudan on Aug 24th 2010, electrical problems (http://avherald.com/h?article=4331c079&opt=0)

A BMI Airbus A321-200, registration G-MEDJ performing flight BD-996 from Khartoum (Sudan) to Beirut (Lebanon) with 42 passengers and 7 crew, was enroute at FL360 overhead northern Sudan when the crew noticed a number of electrical problems, the most significant being the intermittent repeated failure of both the captain's and the first officer's electronic displays, the uncommanded application of left rudder trim and unexpected reactions of the aircraft to flight control inputs. Following an ECAM message "ELEC 1 GEN FAULT" message the crew shut the left hand generator down after which normal operation was restored. The flight continued to Beirut for a safe landing.

Quite a serious incident imho.

[protectthehornet]

thanks for this interesting post.

[DC-ATE]

Us old retired graybeards tried to tell you this years ago.

[Loose rivets]

But it has been reported that investigators have already urged Airbus to alert all operators of its A319, A320 and A321 planes about the potential hazards stemming from such electrical faults.


Have they any suggestion as to what the airlines might do?

[ihg]

For those who are interested...the respective AAIB Bulletin:

http://www.aaib.gov.uk/cms_resources.cfm?file=/S2-2010%20G-MEDJ.pdf

Regards,
ihg

[OldChinaHand]

Yes, stick another OEB in the back of the QRH, to join all the others, another page in abnormal procedures and hope for the best.

[captplaystation]

Sorry to add yet another biased view of a confirmed luddite, but is anyone over the age of, say 40, truly surprised by this.
Too clever is TOO clever and this is yet another incident, that, had it happened at a different altitude or place ,would have joined the list of, at least partially, unexplained airbus whoopsies, headed ignominously by the AF A330.

[jcjeant]

Hi,

http://www.pprune.org/rumours-news/433616-airbus-prepares-safety-warnings.html#post6056913

[MainDude]

Agreed! That worries me - I was hoping that deviant electrons fleeing a faulty GEN would automatically be trapped by at least one of the thousands of logic gates.

ECAM actions for GEN 1(2) FAULT usually calls for turning the GEN off then on again, and if it still doesn't work, turn it off & leave it. You loose the main galley and CATIII Dual - no big deal. No mention in the FCOM about what effects may be caused by a system that half works.

I'm curious though, if the crew followed the ECAM, they would have turned off GEN1 & kept if off if they knew it was faulty, unless the other faults e.g. side-stick fault jumped the queue (being more critical failures) thereby masking the real cause of their problems. Was it a condition with a remote possibility of reoccurrence, or is this an example of when the ECAM logic was inappropriate?

I really hope that this "deviation from design objectives" doesn't get swept away to OEB heaven, and that maybe just perhaps it will work it's way to the italic notes below the GEN 1 FAULT procedure in FCOM3.
................
Oops, just read the link above and the report http://www.aaib.gov.uk/cms_resources.cfm?file=/S2-2010%20G-MEDJ.pdf
Riveting stuff.

Imagine this happens on an arrival or departure in a mountainous area. Can see the TRE's working this into the next sim check scenarios :ouch:

[mohdkarta]

A former A330 driver told me a decade ago that the airbus aircrafts have many traps and the Airbus techies were generally very overconfident; he reckoned that there would be many accidents/incidences caused by those traps caused by transient electrical problems which can not be proved or even replicated. Even in labs and bench tests, a lot of electrical or electronic transients cannot be replicated. Looked like we have the Air France A330 off the African coast and many more which might not make the big headlines........we are all very lucky so far.

People and techies who think a world of themselves ( airbus supporters ) keep burying their heads in the sand. Likewise people who debunks every anecdotal evidence of cell phones usage in aircrafts which lead to the occasional electromagnetic transients which combine with right circumstances can cause great harm to other vital electronics. try as they may, the lab boys cannot never replicate every circumstance surrounding an accident/incident.:ugh::ugh::{

[bearfoil]

So thank goodness the computer remembered to alert to a duff generator. Hats off to FBW!! Let's don't be hasty, let's wait for the final report.

Passe: "What's it doing?".

Now: "What am I doing?"

Next: "101101 10 01101 101?" (What's he doing Now?)

bear

[p51guy]

Flying out of Reagan one night in a Lear Jet in a 30 degree bank to clear the prohibited area had the voltmeter peg out as the left generator went off line. I shut off the right generator and the left one picked up the load with normal voltage. Later I looked through our checklist and found no procedure for our fault. The overvoltage on the right generator kicked off the good left generator. We would have probably fried everything if we had not done what we did. We had some high level Hollywood celebs on board so it would have been interesting if we had followed the checklist.

[SKS777FLYER]

Tho I am no fan of Airbi aircraft and B4 this goes the normal A vs B routine....
I am reminded of the Boeing/ FAA; "hey jeepers folks, the 737's that intermittently roll over and auger in, well they are perfectly safe, nothing to see here, move along."

[sierra5913]

http://www.aaib.gov.uk/cms_resources.cfm?file=/S2-2010%20G-MEDJ.pdf

"The aircraft manufacturer has indicated that a reset of the Flight Augmentation Computer (FAC), caused by an electrical power interruption, may cause a small incremental offset in the rudder trim. Multiple electrical power interruptions can result in multiple increments which could, cumulatively, produce a significant rudder trim input."

:uhoh:

[p51guy]

Does anybody else think 20 miles off course insignificant? That takes a lot of rudder trim.

[Fargoo]

Depends how long the trim goes unnoticed whilst the crew were sorting out the other problems.

Always thought this was a weird foible of the little Airbus, on power up the trim is never zero and usually some random number. Would've thought that was something that could have been engineered out in all the year its been in service.

[TURIN]

To read some of the posts here anyone would think aircraft only started to crash (or at least do something unexpected) when Airbus put their name on the side. :rolleyes:

[Sciolistes]

Last time I read the phrase "a stream of warning messages" was in relation to the Air France accident.

[jcjeant]

Hi,

To read some of the posts here anyone would think aircraft only started to crash (or at least do something unexpected) when Airbus put their name on the side.Certainly not .. aircrafts crashed in the past and will crash in the future no need of Airbus for keep this going ......
The probs is that Airbus planes (with all their rings and bells) were announced (or believed) to be protected of crashing .... you know .. like the Titanic can't sink ...
Pure arrogance ......

[arearadar]

I remember some years ago, a colleague recalls a situation in the hold at Ockham. An aircraft bust it`s level, he instructed BA-XXX to turn left immediately (Not the offending a/c) and then observed on radar that it was in fact turning right. He then instructed BA to turn left,left immediately. BA-XXX said I AM TURNING LEFT!!!!! The pilot took control of the situation, turned left and resolved a nasty situation.

Additionally, a friend of mine, having been left without an aeroplane with the demise of Concord, was on an A320 command course. I asked him how he found it and his reply was `What the xxxxxxx hell is it going to do next.

Dave :uhoh:

[ECAM_Actions]

I know the stats don't currently support it, but it will be interesting to see if the level of computerization that there is on any modern Airbus results in more accidents overall than more mechanical types.

Various bodies burying their heads in the sand aside, how many crashes of an Airbus have been unexplained, either in whole or in part, compared to any other type that crashed? Would be an interesting statistic to look into.

ECAM Actions.

[arearadar]

I think there were quite a few of those messages from the QF A380 too !

Dave:ok:

[Locked door]

Can I please ask all contributors to this thread read the AAIB report? It's not quite as dramatic as this thread makes out.

Found here :- http://www.aaib.gov.uk/cms_resources.cfm?file=/S2-2010%20G-MEDJ.pdf

As another contributor asks, how many 737's have rolled into oblivion?

LD

[ECAM_Actions]

>> It's not quite as dramatic as this thread makes out.

Locked door: I politely disagree. Loss of control of the aircraft (due to an electrical fault no less) is second only to the aircraft actually crashing IMHO.

The crew were extremely lucky they were able to re-gain control, eventually.

That said, I do agree that the A380 was a different incident (accident?) altogether, and can't be compared to this one.

ECAM Actions.

[ELAC]

I politely disagree. Loss of control of the aircraft (due to an electrical fault no less) is second only to the aircraft actually crashing IMHO.

The crew were extremely lucky they were able to re-gain control, eventually.

ECAM Actions,

Locked Door is right. These loose and overly sensationalistic descriptions create false impressions of what occurred that aren't supported when you read the actual incident report.

Your response is a perfect example. Nowhere is it stated that the crew lost control of the aircraft or believed they had lost control of the aircraft. They certainly encountered difficulties with control, but those difficulties were not so severe that the captain felt a need to declare a Mayday and at its worst the bank angle was only 10 degrees. So, no "loss of control second only to the aircraft crashing" and no "re-gain control, eventually."

A likely guess is that the judders experienced were a function of the incremental movement of the rudder trim with each of the multiple FAC resets. The left wing low condition then coming about from the trim position as a result of the sum of those movements. Nobody's going to suggest that either condition should occur or is acceptable, but while disconcerting neither posed a serious problem to maintaining aircraft control.

While the reflex reaction is to bang the drum about those darned electronic airplanes, it is worth noting as some others already have, that many steam driven types have suffered far more severe unexpected control problems with far more deadly consequences. So, perhaps we should keep the scale of the event in perspective.

Personally, I'm more curious about how a GEN #1 fault could provoke a loss of both CM1 & CM2 primary instrument displays.

Regards,

ELAC

[lomapaseo]

I politely disagree. Loss of control of the aircraft (due to an electrical fault no less) is second only to the aircraft actually crashing IMHO.

The crew were extremely lucky they were able to re-gain control, eventually.



Its quite possible that there are semantics here.

Could I ask what control was lost and how long and just how was a safe landing eventually made?

It's quite possible that only some functions were lost while others were only temporary in nature and that the crew was able to use back up control finctions to land safely. Thus no luck was involved just adherence to knowledge and training

[protectthehornet]

regarding the 737 rollover...at least there is a procedure for dealing with it in a mechanical fashion.

one can also use assymetric thrust to deal with it...relatively easy

so, is the airbus procedure, start writing NEW CODE and enter it into the computer?

I don't care for the 737, but I flew it.

I hate the Airbus and didn't fly it, even though I would have earned more money.

what a POS!

[CONF iture]

The commander contemplated transmitting a MAYDAY, but considered that his priorities were to retain control of the aircraft and identify the problem.
That makes sense. Is it also what was thought on AF447 flight deck ... ?

That event reminds the Martinair 767 over NY ... the issue was a battery not properly installed, if I remember correctly.

[iceman50]

Protectthehornet

I hate the Airbus and didn't fly it, even though I would have earned more money.

what a POS!

Typical ridiculous comment from a well balanced individual who does not wear blinkers! :rolleyes:

[fox niner]

Came out a week ago, when everyone's attention was on the, er, 'ashes' in Australia

Almost turned into a different sort of ash in a matter of minutes.

[Mushroom_2]

Could I ask what control was lost and how long and just how was a safe landing eventually made?

You could always try reading the report. Link supplied in a post above.

[TheWanderer]

From the AAIB accident report, page 3:
The flight crew reported that the aircraft did not seem to respond as expected to their control inputs and shuddered and jolted repeatedlyThat could be interpreted as a kind of loss of control, if the aircraft does not respond to control inputs as expected, couldn't it?

[Data Guy]

Remembering AA 587 control problems
That NTSB Report aside, there were 15 SDR reports not seen there of uncommanded rudder/yaw, hard-overs, ‘kicks and ‘jolts’. Some samples follow >
Before loss of AA Flt 587
6/27/96 >SDR #, AWXA9960293, America West A-320
11/15/98 >SDR # AWXA9800221, America West A-320
2/12/99 > SDR # 99UAL900100, United A319
6/27/00 > SDR # AALA20001276, American A300
12/22/00 > SDR # 00FDEA0093, Fed Ex A300
9/19/01 > SDR # 2001UALA02074, United A320

After loss of AA Flt 587
1/17/02 > SDR # AALA20020060, American A300
6/3/03 > SDR # AALA20030633, American A300
8/13/03 > SDR # CA03081900, Part 129 A310.
8/21/03 > SDR # AALA20030886, American A300
1/6/04 > SDR # AALA20040029, American A300
11/12/04 > SDR # AWXA200401278, America West A320
3/22/06 > SDR # F3LA200600010, Frontier A319
5/13/07 > SDR # NWAA07186325251, Northwest A320
8/2/09 > SDR # UALA2009080302310, United A320

And during this same period of time, and not included here were nine ASRS reports; #s 347914, 451388, 470552, 484141, 536451, 540100, 644939, 734999 and 790707.

To access the full texts for these Service Difficulty Reports, go to FAA Link >
FAA :: SDR Reporting [Service Difficulty Report Query Page] (http://av-info.faa.gov/sdrx/Query.aspx) and just enter SDR control number.

To access the full texts for these Aviation Safety Reporting System reports go to search Link > ASRS - Aviation Safety Reporting System (http://asrs.arc.nasa.gov/search/database.html) and enter the report number

Lastly, also a good read > “Over Controlling the Rudder Still Possible After 2001 Crash” By David Evans Aug 10, 2010. Story Link > Over Controlling the Rudder Still Possible After 2001 Crash|Aviation Safety Journal (http://asj.nolan-law.com/2010/08/over-controlling-the-rudder-still-possible-after-2001-crash/)

--------------------

[QA1]

I would be very surprised if this incident was not caused by the condition described in EASA AD 2006 0280. i.e. Burnt pin(s) in the #1 generator feeder engine disconnect plug.

[Janu]

Airbus said yesterday that they are not going to release a "safety warning" but are working on new advice to pilots informing them about the possible electrical fault and how to deal with it. Airbus pledges to continue working closely with the AAIB.

[Beeline]

The AD Explains flickering cabin lights, very common problem that has never caused this level of failure. The main cause of concern is how computers recieving feeds from different buses were knocked out simultaneously. DMCs/FACs.

I lost all power on a ground run once, very scary being in the pitch black with the engines running, even the standby failed, apu not avail. Never followedup the fix.

[wileydog3]

regarding the 737 rollover...at least there is a procedure for dealing with it in a mechanical fashion.

one can also use assymetric thrust to deal with it...relatively easy

so, is the airbus procedure, start writing NEW CODE and enter it into the computer?

I don't care for the 737, but I flew it.

I hate the Airbus and didn't fly it, even though I would have earned more money.

what a POS!]

And if there was a rudder hardover below 1500ft on takeoff, the procedure of unloading the airplane and accelerating worked well IN THE SIM. But fortunately no one had to actually try it in the air. It was anything but 'relatively easy' when one considers how many times many if not most pilots had to repeat the exercise. And 427 and the crash at Colorado Springs proved that combined with startle factor, low altitude, etc, it was not 'relatively easy' for even an experienced crew to resolve in time.

As for the 'what a POS', you do yourself a disservice by posting such comments, -hornet.

It appears however once again we are going to lapse into the Boeing/Airbus version of the American game "Ford/Chevy" and not focus on the real issues. Complex systems fail in complex and often unanticipated ways. Offered as sheer sarcasm, maybe we should go back to open cockpits, fixed gear, biplanes with cables to the flt controls so we can avoid all those complexities.

[J.O.]

It's interesting that (to my knowledge) Airbus has never stated in any flight crew documentation that reports from the cabin of flickering lights are a common indicator of a problem in the electrical network, usually being either a bad IDG or a bad GCU. Experienced engineers know that this is one of the first things to troubleshoot when such reports are made by the cabin crew.

[DC-ATE]

wileydog3 -
It appears however once again we are going to lapse into the Boeing/Airbus version of the American game "Ford/Chevy" and not focus on the real issues. Complex systems fail in complex and often unanticipated ways. Offered as sheer sarcasm, maybe we should go back to open cockpits, fixed gear, biplanes with cables to the flt controls so we can avoid all those complexities.

Ah.....but you forget DOUGLAS and LOCKHEED [the Cadillacs].
And.....you'll have to admit that if we never got into these "complex" systems, we would NOT be having these problems.

I gotta go with the -protectthehornet- as well.

[CONF iture]

I recall hearing about an incident with a A340 out of MRU where the AOA vane was damaged in the stand and went unnoticed or unreported. After take-off the aircraft was receiving erroneous AOA info and the more the PF attempted to increase pitch the more progressively the flight computers lowered the nose as the false AOA data was being received. I think the fast thinking commander switched off some of the PRIM's & SEC's (primary and secondary flight computers) and managed to return in direct law.

Any official report on this ?

A single damaged AoA probe is not supposed to do that ... ?
In the meantime it is true that a single dysfunctional ADIRU did the mess it did on QF72 !

[noperf]

B737 rolling over? Is this in reference to the crash near Pittsburgh or Colorado Springs? If Pittsburgh I seem to recall that the flying pilot did not dis-connect the auto-pilot but left it in CWS.

[TheWanderer]

Read here for some informations regarding the B737 rudder rollovers: The Rudder Story (http://www.b737.org.uk/rudder.htm)

[Alpinepilot]

Time to give credit, I think. It is DARK at 0200 in the morning, just north of Khartoum at Fl360, Comms are not easy with either KRT or CAI. These guys were in the middle of a 3 day rotation in the middle of the circadiam low. I know , I've been there. I think this crew handled this in a cool and collected manner without loosing control , resolving the problem and making great decisions. Clearly not such a catastrophic event as some above would say or they would have ended up in Cairo not Beirut! I am sure appropriate guidance will follow. Well Done Guys.

[White Knight]

regarding the 737 rollover...at least there is a procedure for dealing with it in a mechanical fashion.

one can also use assymetric thrust to deal with it...relatively easy

so, is the airbus procedure, start writing NEW CODE and enter it into the computer?

I don't care for the 737, but I flew it.

I hate the Airbus and didn't fly it, even though I would have earned more money.

what a POS!

Yep - it was so relatively easy that Colorado Springs and Pittsburgh NEVER happened:ugh::ugh:

Why 'hate' an aeroplane you've never flown? That's a rhetorical question by the way as I know the answer!!!!

You Are An Idiot:rolleyes:

[p51guy]

Maybe all of us don't want to experience the bad results others have experienced first hand. My friend had an out of control A300 trying to land at MIA with uncommanded rudder movements. He knew they were going to crash but not exactly sure where. Then the AA587 crash in New York in 01 that got blamed on the FO using too agressive rudder movements for some strange reason. Airbus probably had a lot of input in that investigation. Recently the A380 and A321 with the massive electrical faults. No, I elected for the smaller paycheck to fly an airplane I trusted. If you trust the Airbus, go for it. I chose not to. I never felt like an idiot for what I did with no personal experience. I learned from other people's experiences rather than verifying it for myself.

[darmog41]

Wonder how many have noticed that a certain aircraft type name is an almost perfect anagram of HUBRIS. Nearer perfect if you consider "H" is English pronounced "Aitch". The gods on Olympus will be laughing again.

[darmog41]

Wonder how many have noticed that a certain aircraft type name is an almost perfect anagram of HUBRIS. Nearer perfect if you consider "H" is English pronounced "Aitch". The gods on Olympus will be laughing again.

[Machinbird]

Once upon a time, a USN F-4 experienced an electrical fire in the rear cockpit behind the C/B panels. The resulting arcing and sparking caused the AFCS (Stability Augmentation Portion) to experience intermittent electric power. The GIF (Guy in Front) experienced continuous transient control inputs as power was applied and removed from the AFCS. These inputs (and probably the smoke too) panicked him to such an extent that he promptly ejected out of an otherwise good flying machine without first addressing the electrical aspects of the rear cockpit fire. The GIB was also forced to eject since he had no controls in that cockpit.

Now this was an aircraft with essentially direct mechanical connection to the flight control hydraulic cylinders (The stab aug had limited control authority.)

Now forward to the 21st century. An AB aircraft experiences intermittent electrical power from a generator and that situation so confuses the electrical system that essential equipment is not continuously supplied with electrical power. The warning system itself (ECAM) has intermittant power and is continually being reset thus it doesn't settle down to display a clear warning message. Fortunately a clear warning message finally drifts across the screen and the crew responds and shuts down the left generator which begins the resolution of their problems.

But suppose the ECAM never settled down? How would this crew have addressed the problem then? Perhaps some memory item procedures are needed. If essential electrical systems are not continuously powered, does this still meet certification guidelines? Suppose a similar problem cropped up at rotation or on final.

And before all the B guys get too smug, ask yourselves what would happen in your machine if critical displays and systems continually were shuttled between busses by an intermittent electrical problem?

[DC-ATE]

Machinbird -
And before all the B guys get too smug, ask yourselves what would happen in your machine if critical displays and systems continually were shuttled between busses by an intermittent electrical problem?

Maybe that's why us "D" guys never worried, as you could take every switch and lever in the cockpit [except the fuel shut-offs and tank selectors] and place them in other than their normal position and all you lost was some lights and "power steering" !!

[protectthehornet]

White Knight...of course those tragedies happened and that is why we now train how to handle them. I am not an idiot...except for picking an airline that picked airbus...that I will admit.

DC ATE...thanks pal. Anyone who has every flown a douglas understands the sheer simplicity, and therefore elegance of systems. One of the great designers there had the word KISS on his wall...keep it simple, stupid!

Let's face it, the wizardry of the airbus helps for fuel efficency and a lighter structure.

Give me a heavier plane that doesn't break so badly if properly maintained.

I feel sorry for the airbus button pushers...they may levitate, but they ain't flying.

[DC-ATE]

As I've said a few times on here: I'm just glad I'm out of this racket and don't have to worry 'bout it any more. I don't even fly any more !! Trains, boats, autos are good enough for me.

Good luck to all that have to put up with all this "automation".

[p51guy]

I didn't get in the crazy automation era but still felt it coming. Guess we were lucky to get out when we did. I didn't have to put up with the Airbus mentality of flying. Computers are great if they are right. Not so great if they are wrong. Maybe I am just old fashioned. My first airplane didn't have a battery in it. My biggest aviation problem was finding somebody to prop me.

[Graybeard]

And before all the B guys get too smug, ask yourselves what would happen in your machine if critical displays and systems continually were shuttled between busses by an intermittent electrical problem?

A newish 737-300 at America West suffered EFIS blanking, etc., that was traced to intermittent electrical supply connector contacts. The crew took it in stride.

Well designed systems will accommodate intermittents that would cause cumulative errors in less robustly designed systems. A/B will figure it out and fix it, retrofitting the robustness should have been there in the beginning.

GB

[Flap 5]

Blanking screens has happened before on the A320 in the 90's. That was due to an over zealous pilot inserting too many possible alternates and overloading the computer memory. It didn't happen to the rest of us because we were aware that it was a possibility and didn't push our luck.

It is also important to use common sense, even on an Airbus. The manual doesn't cover all fault scenarios as has already been mentioned. I remember an A320 having a wing tip brake come on where the ECAM assumed an assymetric flap condition. In fact the flap had locked at flap full but the ECAM instructed to put the flap switch to flap 3. This resulted in overcontrolling by the pilot and a difficult landing.

I had the same fault at my next simulator check. The flap on the controls page showed it was in full but amber. I landed normally with the switch at full and wondered what the problem was supposed to be. Only then was I told that what I was given was what had happened for real, but the crew had pedantically followed the ECAM message. Even my F/O in the simulator was trying to point out my incorrect procedure because I wasn't following the ECAM message.

It would seem that some would just follow the 'correct procedure' without using common sense even if there is no correct procedure for the actual condition present at the time or they have misdiagnosed the condition.

[Clandestino]

It's not the first time Airbus electrics have thrown a tantrum. AAIB reports on G -EUOB (http://www.aaib.gov.uk/sites/aaib/publications/formal_reports/2_2008_g_euob.cfm) and G-EZAC (http://www.aaib.gov.uk/publications/formal_reports/4_2009_g_ezac.cfm) incidents are IMHO compulsory reading material for any aspiring or current bus driver.

Basics of all three incidents are simple: E in EFIS & ECAM stands for electronic and electronics needs proper electricity to work. If a bunch of screens go crazy your problem is a) electric b) likely to affect ECAM, don't expect it to work as advertized or at all.

So how do we solve problem of ECAM-junkies at the time of ECAM going on vacation? We can introduce memory item like : LOOK UP! Yes, as A320 pilot one is free to look at overhead panel even if ECAM doesn't direct him to do so. Chances are there will be some or other Pb glowing amber and pushing it might solve a problem. Wait a sec here! Don't just push it mindlessly, take a look, read what's written on it, recall what it does and what will be the consequences. Simple, really. Or not, if you learnt the systems by rote to pass the exam. Then it's really tough times ahead for you bro.

Regarding the Magic Bus and today's pilots: that Airbus is crash-proof and can cope with less skilled pilot than standard is misperception, promulgation of which is the fault of Airbus propaganda department, not the fellows who designed the Airbi. Woe to the airline whose training department takes this sales pitch to be true. Compared with a couple of decades ago, modern pilot has replaced: pilot, flight engineer, radio operator and navigator. Creating better and easier to operate systems was meant to decrease workload. It succeeded yet the intention was not to make life in cockpit easier: it was to reduce workforce as much as possible. It is all fine and well as long our electronic little helpers do their work. When they pack up, you have two people doing the job that was historically split between 4 to 6.

[Swedish Steve]

before all the B guys get too smug, ask yourselves what would happen in your machine if critical displays and systems continually were shuttled between busses by an intermittent electrical problem?

In 1991 BA received delivery of B737-400s fitted with the new VSCF, instead of IDGs. (Variable speed constant frequency).

Anyway a two week old example arrived here with the following defects.

Galley power repeatedly switched itself off
Lighting system flickering, cabin and cockpit.
Flight Recorder OFF light intermittent ON.
EFIS and FMC dumped all info and L Nav and A/Thrott disconnected, Track disappeared from EFIS
Pressurisation problem felt but no warnings

Then nbr 1 eng gen bus off light on, and all back to normal.

BA soldiered on with the VSCF for many years, but finally gave up and converted to IDGs.

[Oriana]

Whilst we're praising Douglas, I suppose we won't mention about Cargo Doors blowing out or flipping on their backs on landing every so often.:hmm:

No aeroplane is perfect.....4500 A32X family aircraft later, they're certainly no POS - and if you're asking 'what's it goi ng to do next' - I suggest you don't understand the machine.

[reverserunlocked]

A job well done. Dark, IMC, light turb, poor comms, unappealing diversion options - they earned their crust that night. Let's wait for the report.

[CONF iture]

Regarding the Magic Bus and today's pilots: that Airbus is crash-proof and can cope with less skilled pilot than standard is misperception, promulgation of which is the fault of Airbus propaganda department, not the fellows who designed the Airbi.
Where do you see Bernard Ziegler (http://en.wikipedia.org/wiki/Bernard_ziegler) then ... ?

[Razoray]

I find it interesting that Boeing's prized aircraft had a severe fire and meltdown the other day and all seems quite the norm....Don't worry Boeing will take care of that!!!!!

meanwhile an incident on a A320 and now we are lead to believe that Airbus is crap and the ill result of the overly teched modern era.....

Enough is Enough....if we want to compare apples to oranges, more Boeing's have hit the dirt than Airbuses...but that's not the point......

Point is who cares...

I have no preference for either aircraft, but I will say for those who are afraid of modern technology, I don't leave messages on my Dads cell phone because he doesn't know how to retrieve them.......:)

[Con Catenator]

AD mod status :confused:

Does anyone know the MSN of the subject aircraft ?

[protectthehornet]

razoray

there is a difference...the 787 is in its test program and is not taking paying passengers aloft.

the A320 series has been taking people for a ride now for quite awhile. too bad they are now part of the new test program.

[Razoray]

Will the 787 ever take a paying customer??

All I'm saying is Boeing and Airbus both make good aircraft.....but as shown not perfect....just sick of the battle.....

we all have no choice but to fly one or the other......

[stev]

right well good job this post has gone form talking about an Airbus incident, to an A vs B argument and then to attack the 787, waiting for somebody to come after the A350 and we'll have all the hacks out. I for one am very happy with my American made aircraft but i would not be arrogant enough to either say that either Airbus ( an airplane that i have been an engineer on in a previous life) or my preferred maker of airplanes has the right idea, all us that sit on the business end of the craft must remember one simple rule it's only a Computer. A lot of the incidents of recent times have come from lack of knowledge of what the system is doing. Much of what Airbus tried to eliminate in the making of the A320 has been taken care of in the major developments of teaching of the modern elements of CRM. Leaving it to the computer may not be ideal. We have now come around to a state that pilot skills have been so degraded that even the whizz kids at Airbus are having a rethink about the control the cockpit can exercise. (In my limited knowledge direct and ultimate is the only answer.) Whichever side of the Atlantic your ideology sides TRAINING of the Aircraft systems and an integrated knowledge may save the day. Short Jar 25 courses are not the answer.

Well thats my 2 and 6 pence

awaiting the bashing

[wileydog3]

B737 rolling over? Is this in reference to the crash near Pittsburgh or Colorado Springs? If Pittsburgh I seem to recall that the flying pilot did not dis-connect the auto-pilot but left it in CWS.

recall is incorrect. Besides, even if it were 'left in CWS' it would not have mattered.

[wileydog3]

I feel sorry for the airbus button pushers...they may levitate, but they ain't flying.

..probably what the first guys said when they enclosed the cockpit.

Wonder why Boeing fell into the trap of FBW and all the magic? And let's forget the triple7 that went a bit funny a few years ago with its FBW.

The bashing and bias are what make a lot of us drop out of these discussions.

BTW, what ARE you FLYING these days?

[jandakotcruiser]

Back in 1995 I heard of an MAS A330 stranded in ADL with an unusual problem. The flight was AOG because of a flap assymmetry problem.
The inbound flight crew had departed KUL with an MEL deferred item pertaining to wing tip breakers which allowed despatch with the proviso the deferred item be fixed within a fixed number of days ( I can't remember the details ).

However when the outbound crew started their preflight, the wing tip breaker system locked out permanently and the station engineer was unable to make head or tail of what caused it despite the direct communication with MAS maintenance base in KUL. Even the Airbus techies stationed in KUL was not of much help. The outbound flight crew returned to their hotel only to meet up with the inbound flight crew who was also puzzled as they had been assured in KUL that the WTB lock out system has been overridden and despatchable for a number of days. Then the inbound captain asked if anybody had messed around with the flight deck clock system. The outbound f/o sheepishly admitted fumbling whilst setting the clock and had reset the f/o side clock after letting the date/month run past sveral months! Apparently the aircraft computers' time base is linked with the flight deck clocks.

Only when they advised the engineering of this that the Airbus techies in KUL realise what the problem was. I don't know how true this incident was but it was brought up in one of the technical meetings pilots had with the engineering boys. Just a little story..............................

[Rananim]

I wont kick Airbus as its bad manners to do so when someone is down..but just how many undiscovered fault scenarios are still out there.The story of the commander taking out the PRIM/SEC so that he could control the aircraft correctly in pitch is worrying as it requires quick lateral thinking which some may not have.So are the incidents of radar alt controlling laws and the pilots ability to land(recent incident plus a qantas 330 incident a while back)..I believethe airbus peole were well-intentioned and produced a landmark machine but the over-confidence was sickening..you cannot have a computer run things in something like flying with so many variables.The man is still better..let the computer warn him by all means but not control him.Boeing and others are imperfect but you as the pilot do control your own destiny.I like it this way.Monitor me,warn me but give me control.always.

[iceman50]

As is the norm these days on PPRUNE the "usual suspects" have hijacked a thread to spout their hate of Airbus. Truly unbelievable especially as they have admitted to never flying them.

The "urban legends" have also come out of the woodwork in a further attempt to decry Airbus.

You really are SAD people and as for the A330 story in ADL it just goes to prove what a few of the sensible posters here have been saying, some "pilots" do NOT know their aircraft!

[jcjeant]

Hi,

Ah yes .. urban legends
Note that this is not an urban legend:
Ziegler said to the press in a interview:
This aircraft (Airbus) can be controlled by my concierge
Methink Ziegler can't be suspected to hate Airbus :)

[BOAC]

It really is time to analyse what it is that is causing this problem.

Point 1: The AB 319 onwards are clever and sophisticated aircraft. The technology is extremely advanced. I view it as a significant step along the aviation path. It generally makes life (and eating crew meals) a lot easier. Personally I dislike the side-stick concept from a monitoring p.o.v. but otherwise the a/c has a lot of plusses.

Point 2: The 'POS' that PTH talks about is not primarily the aircraft nor the technology. It sits at the desks of all those managers, accountants and airline training departments who have swallowed the AB hype - starting with Bernard's.

Point 3: If all is working well, the a/c will NOT readily let you kill yourself or your passengers.

Point 4: If all is NOT working well, it will. It has the ability to remove its defences and either not let the pilots know or confuse them with its functions.

To summarise: If all the above 'POS's' would realise this, that there are obvious faults in the software as with ANY aircraft that uses computers, the world will be a safer place. Teach pilots NOT to trust implicitly. Teach them to be wary of the machine. Teach them to retain basic airmanship and flying skills. In other words, to watch out for themselves. Had the PGF crew done this, even given the altitude was hopelessly wrong, they would most probably have survived and snagged the AoA sensors on landing. As with the latest electrical shenanigans, crews need to be aware of all the wrinkles and what to do when ECAM fails. It is not what it is hyped to be. Acceptance of this by some would go a long long way to sorting out a lot of the problems. Remember the infallible 'system' did not protect the AB CTP out of TLS. I think that is a significant lesson for all.

Time to end this boring battle here and accept that FBW is here to stay and will get more capable. Let's make sure we all keep up with it.

[hetfield]

for the A330 story in ADL it just goes to prove what a few of the sensible posters here have been saying, some "pilots" do NOT know their aircraft!So dear iceman,

please tell us what's wrong with that "story".

Thx

Everybody else may have a look @ 8. on page 2/6 :ok:

http://www.kwauk.com/Files/A330%20Manual.pdf

[DC-ATE]

iceman50 -
As is the norm these days on PPRuNe the "usual suspects" have hijacked a thread to spout their hate of Airbus.

It's not so much "hate of Airbus" as it is the dislike of all this "advanced" technology that is supposed to be making flying more safe. There doesn't seem to be much validity in that. There are just as many "incidents" [maybe more] now as in the past. At least we had control of our airplanes even when all systems failed "back then".

EDIT: P.S. This applies to the new Boeing products as well.

[firstfloor]

Very odd that rudder out of trim not noticed for several minutes and late notification led to loss of flight data.

[Dont Hang Up]

There are two threads topping the forum at the moment. Once concerns a potentially dangerous uncontained engine failure. The other concerns a potentially dangerous software failure.

It is curious to see the difference in attitude.

The hardware failure is a taken as cause for concern - but the emphasis seems to be "find the root cause, design a fix, and move on. After all, these things are bound to happen from time to time in such complex machinery."

However, when the problem is software - even if the occurence is comparably rare - the attitude seems to be that this is completely unnacceptable. Furthermore it is used as some kind of proof that the underlying philosophy of the aircraft is flawed.

Why the difference I wonder?

[DC-ATE]

Dont Hang Up -
Why the difference I wonder?

Could be that pilots [real pilots, not the newer computer pilots] like to have a feeling of being in control rather than have some computer telling them what to do all the time. And then when the 'software' fails, they become passengers, not pilots.

[PPRuNeUser0204]

ould be that pilots [real pilots, not the newer computer pilots] like to have a feeling of being in control rather than have some computer telling them what to do all the time.

As an Airbus pilot could you explain the above?

[DC-ATE]

Maybe I should have said having a computer "limit" what they can and can't do. As an Airbus pilot, perhaps YOU can explain.

[Rananim]

I think he already said that judging by your location and age,it would be a waste of time

[DC-ATE]

Rananim -
I think he already said that judging by your location and age,it would be a waste of time

If you're referring to me, fine. I'm not going to argue the point. I'm probably the wrong one to do it anyway. I never scratched a piece of tin in thirty years of flying and only shut down ONE piston engine [an R-2800], and throttled back on ONE turbine engine [a JT-8]. As close as I came to onboard computers was the 737-300. I spent most of my time telling the Co-Pilots to get their head OUT of the cockpit and look outside for traffic instead of playing with the computer all the time.

All I can say is.....Good Luck with all your fancy stuff. We got along just fine without it. I will admit though, it was nice to have INS between the mainland and Hawaii. But.....there again, we found the Islands without it too.

[White Knight]

Could be that pilots [real pilots, not the newer computer pilots] like to have a feeling of being in control rather than have some computer telling them what to do all the time. And then when the 'software' fails, they become passengers, not pilots.

I fly the 'Bus - the thing does what I tell it to. No question about it... It's like a big vicious snarly dog really. Kick it in the balls and it's all yours:}:}

[Razoray]

DC ATE

There are just as many "incidents" [maybe more] now as in the past.Really.......??????

Fatal Crash Rates per Million Flights

Airbus A320/319/321
47million flights Rate .12
Boeing 737-600/700/800/900
28million flights Rate .14
Boeing 727
76million flights Rate .49
Douglas DC 9
62million flights Rate .57
Douglas DC 10
9 million flights Rate .66

Stats provided by Airsafe.com

[chris weston]

DC. I'm with you all the way.

But ..... thy bean counters will quote thee the increasing statistical safety of modern aircraft and will cite automatation ad nauseum.

Razor you beat me to it!

CW

[p51guy]

DC-ATE, no he was referring to me but they pulled my post because I referred to Europes bias to the Airbus. He called me ignorant because I thought France and Airbus were protecting their product, especially in reference to the Air France Airbus lost off the Brazilian coast line. They will probably pull this post too so it probably won't be here tomorrow. Read fast. This is how it is done here. Ask anybody.

[goldfish85]

Back some twenty -some years ago, Tom Foxworth (Pan Am, then UAL) wrote a novel called Passengers about the first FBW airliner. I think I'll reread it again.


Goldfish

[vapilot2004]

Razoray - Factor in hull losses and those numbers change considerably.

That said, for most of the modern fleet built since 1980, one type is not inherently safer than another. Each machine has pitfalls that once known can be mitigated in operation.

We run into trouble when new problems arise or preexisting problems formerly hidden beneath layers of metal, wiring or software rear their ugly and untimely heads.

[lamina]

Razoray

The numbers you mention have one thing in common-

The use of EGPWS, without doubt the single biggest contribution to safety in the last thirty years.

[Fargoo]

DC-ATE, no he was referring to me but they pulled my post because I referred to Europes bias to the Airbus. He called me ignorant because I thought France and Airbus were protecting their product, especially in reference to the Air France Airbus lost off the Brazilian coast line. They will probably pull this post too so it probably won't be here tomorrow. Read fast. This is how it is done here. Ask anybody.

There you go, tinfoil hat firmly on head i've quoted you so that they will have to delete two posts to protect franco-airbus interests from the nasty american forum poster :ok:

Anyway, back on topic. Does anyone know how long there was between the incident happening and the AAIB being notified? Perhaps the usual ASR was raised and no-one in the airline considered a gennie tripping off line was reason to report the incident. Could explain why the FDR data was overwritten.

Not saying this is right but if the AAIB was informed everytime there was a fault on an aircraft they would be quickly overwhelmed.

Airbus really do need to update the FAC software though to prevent multiple power interupts from building up a rudder trim that may affect the flight path. Not sure why this was never addressed in the 20+ years its been in service.

I'd also quite like to see Airbus / IAE adopt a terminal block style disconnect for the pylon/engine IDG feeder cable junction rather than the plug and socket arrangement they use at the moment. It has and still does cause quite a few power problems. It's been a problem even going back to the E4 powered 757's. Can't recall a properly tightened terminal block connection a la 767 RB211 ever causing these problems.

[demomonkey]

Anyone cast any (informed) opinion on the idea of switching the 'AC ESS' bus to ALTN to see if it restores power?


And to the ludites who smugly type 'told you so'; having flown Boeings and smaller Scarbuses I have to say that the Airbus is damn good and whilst the electrical sensing equipment maybe overly sensitive (95% of things are fixed by a CB reset) it is an extremely reliable aeroplane. Talk of how the old days were so much better is just looking at the world through rose tinted spectacles.

[max nightstop]

Informed opinon on AC Ess to ALTN.....

Yep it might work, but since no one knows why an intermittent fault on GEN 1 would cause all the screens to blank, no one knows what switching the AC ESS BUS to feed from GEN 2 would do. It might have fixed the screens but not the FCC resets that were troubling the rudder trim.

Ultimately, since the fault lay in GEN 1 connections, the answer was to switch it off. If the AC ESS switch had cured the immediate problem of the screens, they might have been left with an arcing contact on GEN1 that was causing more insidious problems.

The fact that this incident wasn't investigated through the FDR ought to be a crime. What the hell were the Operations, Engineering and Flight safety managers doing?

[gusting_45]

Niaive to imagine that improvement in air safety statistics is due to aircraft automation and computerisation. As one who has flown older a/c Lockheed L188, B727, &737 classics, whilst more recently and currently A319/320 to me the biggest loss in the transition to the older aircraft to the newer is the loss of the flight engineer. Without a shadow of a doubt the greatest step backwards in aviation safety, IMHO.

I also had a spent quite a few years working in the IT industry before starting to fly, the statistics regarding logic - syntax - coding errors per line of computer instruction code would truly make your hair turn white.

Nonetheless, I have quite a few years left flying the minibus and it's degree of automation and computerisation doesn't particularly concern me, other things do but not that.

[Graybeard]

Back about 1979, when McDouglas had promised the unions no new two-crew plane after the DC-9, and they were following with the DC9-80, it was noticed the airliner with the best safety record of all was the 2-crew 737, followed by the DC-9.

That quashed the argument, the name was changed to MD-80, and some 3-crew 767 were run back into the factory to take out the FE position.

GB

[Flap 5]

Inevitable to see the loss of the flight engineer raised eventually.

The biggest improvement to flight safety concerning pilot error is that of situational awareness. The PFD and navigation displays have made situational awareness much clearer, leading to fewer confused pilots. Pilots are easily confused.

[gusting_45]

Situational Awareness is a lot more than the PFD and ND.

Otherwise, I agree with you.


All the electronic monitoring in the world will not, for me, replace the benefit of another human brain in the cockpit. Computers are fantastic tools but are there only to aid the human.

In my ex-company the F/Es were an integral part of the flight crew and wholly included in managing the flight. I suspect that there are those who would make the same case for the Navigator as well and undoubtedly there are some CFIT accidents that would have been saved by the presence of one.

However, the accountants and bonus driven managers rule the world. Computers are cheaper than people, and the actuaries develop another spreadsheet which shows that the cost/benefit ratio favours paying for a few hull losses over paying for more crew.

Just because I'm cynical doesn't mean I may not be right.

[hetfield]

@gusting 45

I fully agree with you:ok:

Hetfield

(3 years FE 727, 5 years FO 727, 21 years Busdriver A300/320/340)

[FatFlyer]

Hi, flickering, blanking screens showing crosses( display computerfault), errors with QNH/STD , rudder trim limit fault. FAC fault, are all problems which I see almost every day on the bus(along with window heat controller)
These sound very similar to the problems the BMI crew had except ours are caused by poor ground power units when sitting on stand with fluctuating voltages or handlers knocking the connector, and not at 36000 feet.
Possibly voltage spikes from faulty GCU?

[DRJHNEWMAN]

Have these faults been rectified?

[goldfish85]

According to my files, it's 2190


Goldfishfile:///C:/DOCUME%7E1/DICKNE%7E1/LOCALS%7E1/Temp/moz-screenshot.pngfile:///C:/DOCUME%7E1/DICKNE%7E1/LOCALS%7E1/Temp/moz-screenshot-1.png

[vapilot2004]

Have these faults been rectified?

On the incident aircraft, one would hope so. On the fleet, I highly doubt it. Given more time, I am sure we will soon see some telexes addressing the issue once a determination is made as to the direct cause and proposed solution.

[autoflight]

I have experienced vibration for many months in an A320 and in this case my company's engineers declined to consider mechanical possibilities. Finally disrupted flights drove company to consult with AB.

1 bolt out of 4 was holding the horizontal stabiliser attached to the aircraft.

Concentration on the electronics must not divert us away from other possibilities that can cause very bad results.

[vapilot2004]

Concentration on the electronics must not divert us away from other possibilities that can cause very bad results.

That's just it isn't it?

Computerization is all well and good and electronics have come a long way beyond what was state of the art just 2 decades ago, but both of these advances in technology have native limitations in understanding via sensors and algorithms when things mechanical, electrical, and/or aeronautical go wrong.

It's not at all down to a science just yet no matter what the sales team may come up with. The sooner we honestly come to grips with these limits of the state of these arts, the better we all shall be - particularly with said systems and their component parts now reaching 'an age'.

A mitigation technique? Keep the PF in the loop at all times.

This last suggestion applies all across the board from shore to shore, manufacturer to manufacturer, and lastly engineering to final "out of beta" product.

[Fargoo]

1 bolt out of 4 was holding the horizontal stabiliser attached to the aircraft.

Really? Only 1 bolt holding the stab on?

[DRJHNEWMAN]

Thanks! I Appreciate Your Reply.

[fotoguzzi]

Don't you give that thing a shake before each flight during your walkaround?

(I keed! I keed!)

[Captain-Crunch]

A poster was mentioning that the crew was experiencing "shuttering" which I suspect could be flight spoiler reaction. At least on the previous airframe, the A300/310/B4's, the bird had no inboard ailerons at all like Boeings and Douglas used for cruise, and the outboard aileron is locked out once clean: a feature, no doubt, adopted to save money, complexity etc.

But the downside to this reliance strictly on roll spoiler mixing software for roll control when clean, is that once again you are reliant on lots of questionable computer code. Every heading change was jerky since popping boards up in cruise to bank cause an undesirable yaw, which had to be either countered by an opposing flt spoiler deploying on the other side, or an input by the yaw damper, or a combination of both. When it rained hard in the tropics, the system would give up and fault right when you needed it most: a high bank command. Even when it didn't rain, the system would give up sometimes over 300 kts banking in a high speed descent under ten thousand. This was a normal high speed descent legally permitted in some international operations but the airplane couldn't hold it together and deal with a thirty degree bank down low. A number of distracting flt spoiler faults (five was common) would light up amber and roll control would be partially lost causing the A310 to overbank uncommanded to 45 degrees. It took full opposite control input to right the ship, or a smart non-handling pilot to reset the overhead ignoring the ecam procedures. We got tired of this happening, so quit writing it up since the damn thing was always signed off "byte checks O.K.". It was clearly a known deficiency with Airbus flight control design, in my humble opinion. But you-know-who certified the airplane to fly like this, so we lived with it. Those of us who experienced this unsettling anomoly, would speculate that maybe the software engineers just never envisioned someone operating at over 250 knots below ten thousand.

I have never flown FBW but have jumpseated with the sidestick boys and it makes me nervous. Not modulating your own bank angle and putting your own back pressure into the turns Means Manual Law skills are lost after a time, doesn't it? But they all have faith in the design of their machine, something that I am in short supply of the last few years regarding the industry's over-reliance on automation.

What happens when these FBW airframes get older and cannon plugs and connectors suffer inevitable corrosion? When Airbus flooded the market, a lot of us worried about the composite airframes but our suspicions about an aging vertical fin for example, inspected by an outsourced low-cost maintenance provider was dismissed as Old School paranoia. Surely, we were told, anything new and advanced that the government sanctions must be better for you, right? Next thing you know, one breaks up over new york and the pilot is blamed for using the rudder. A memo comes out telling me not to use the rudder if I can help it! :rolleyes:

I just don't know anymore. Let's face it: like the Titanic and the Hindenburg, some vessel designs were doomed right at the drafting table.

Could you miss the mountains in a pull up with this type of g-limiting and bank-limiting A320 FBW sidestick?
No, I don't think you can. FBW will save the airframe from overload first, but ultimately hit the rocks as I understand it. It will reject the pilot's command to pull say seven g's. FADEC will slow spool the engines to save TBO but hit the trees as it did in Toulouse. Flying around on Alpha mode on the back side of the power curve is insane below ten thousand feet but simulator gods, test pilots and check airman seemed unconcerned about fostering such a dangerous habit when we first got the airplane.

At least that was my observation: that illogical reverence for a bunch of software code was committed on a daily basis by the Airbus Cult. "It's Advanced! It's Advanced!" they would all sing in unison. While I was impressed with the power-to-weight performance of these light twins as compared to the older heavy boeings, I sure was not impressed with any of the automation. So I just turned it all off and hand flew it. It was a predictable decent flying airplane when you operated it at the lowest level of automation: da pilot.

But that went over about like a fart in church with the standardization mafia. "I needed to get the Airbus Religion" I was told when I objected to the classification of hand flying as "John Wayning" the airplane. They wanted me to use all these nanny protection devices all the time.

They were nuts imho. The next thing you knew machines were wrecked all over the place due to inability to make normal hand landings.

I don't know about both the A320 and the A330. I don't know about Trent engines either.... on the 777 or the A380. Just like the Comet they all have a good safety record now, but just like digital home computers, corruption may be lurking.

I never did like ETOPS either, or getting my bags and balls x-rayed to go flying. I think I'll avoid all those things from now on if I can. I think I'll only ride on 411A's L-1011 or a nice redundant 747 in the third world somewhere where they treat you nice in security.

I know, I know.

Just let me get my coat and hat....

[Fargoo]

I have never flown FBW but have jumpseated with the sidestick boys and it makes me nervous. Not modulating your own bank angle and putting your own back pressure into the turns Means Manual Law skills are lost after a time, doesn't it? But they all have faith in the design of their machine, something that I am in short supply of the last few years regarding the industry's over-reliance on automation.

At least that was my observation: that illogical reverence for a bunch of software code was committed on a daily basis by the Airbus Cult. "It's Advanced! It's Advanced!" they would all sing in unison. While I was impressed with the power-to-weight performance of these light twins as compared to the older heavy boeings, I sure was not impressed with any of the automation. So I just turned it all off and hand flew it. It was a predictable decent flying airplane when you operated it at the lowest level of automation: da pilot.

Not sure I follow your prose on this one.

as for byte check , if someone is signing that in your tech log i'd seriously question any other work they've carried out.

All very strange for one post :confused:

[DC-ATE]

Captain-Crunch -

Great post. I'd be interested in knowing what you are, or were, rated on. Thanks.

[Fargoo]

Anyway, back on topic slightly.

I filmed a short (but poor quality) video of the rudder trim and what happens when power is interrupted to the FAC - in this case FAC1.

YouTube - A320 FAC Reset - Rudder trim incrementing (http://www.youtube.com/watch?v=MT0NJiRFA1s)

[iceman50]

DC-ATE
Captain-Crunch -

Great post. I'd be interested in knowing what you are, or were, rated on. Thanks.

Only great because it reaffirms the luddite mentality!:rolleyes:

Captain-Crunch

All that from someone who has NEVER flown the aircraft!:ugh:

[DozyWannabe]

To read some of the posts here anyone would think aircraft only started to crash (or at least do something unexpected) when Airbus put their name on the side. :rolleyes:

To say nothing of the belief that the introduction of digital flight management systems and the ability to misprogram them is peculiar to AI aircraft (Hint, guys : AA695 at Cali, which was a B757)

Although I admire the technical brilliance of the aircraft I dont like the fact that even when you disconnect the automatic's and fly you never really have full control of the jet. Every input is monitored and possibly modified by a number of computers if deemed nessasary.

The only time the computers "modify" the input is if you try to exceed 60 (IIRC) degrees of bank, or fail to increase power while pulling hard up in an evasive maneouvre - otherwise with the FMS disengaged, she's all yours.

I recall hearing about an incident with a A340 out of MRU where the AOA vane was damaged in the stand and went unnoticed or unreported. After take-off the aircraft was receiving erroneous AOA info and the more the PF attempted to increase pitch the more progressively the flight computers lowered the nose as the false AOA data was being received. I think the fast thinking commander switched off some of the PRIM's & SEC's (primary and secondary flight computers) and managed to return in direct law.

Which is the correct thing to do in any airliner, almost all of which have some digital automation these days. If the aircraft isn't doing what you want it to do, disconnect them and fly the thing!

(And yes, Rananim - I think that knowledge of how to do just that should be part and parcel of the FBW A3X0 pilot's toolkit. At the end of the day it's no different from switching out the Sperry on the old 727 and Jurassic 737)

Ah.....but you forget DOUGLAS and LOCKHEED [the Cadillacs].

So the poorly-engineered cargo door locks and mismatched autopilot computers on their respective final-generation airliners - both of which were causal to fatal accidents - are figments of the imagination?

And.....you'll have to admit that if we never got into these "complex" systems, we would NOT be having these problems.

That's as maybe, but you'd definitely still have the odd augering into the ground when someone pulled a lever or set a switch they shouldn't have (see EAL66 and AC603 - both DC-8s).

Additionally, a friend of mine, having been left without an aeroplane with the demise of Concord, was on an A320 command course. I asked him how he found it and his reply was `What the xxxxxxx hell is it going to do next.

To which the correct answer is "absolutely nothing other than what you tell it to". I'll paraphrase what someone else said earlier and say that if you don't understand what you're telling it to do, you need to do your bl**dy homework sharpish!

I suspect that as a former Concorde (just out of interest, was dropping the "e" intentional? :E) pilot, understanding the FBW Airbus series is well within his abilities.

Regarding the Magic Bus and today's pilots: that Airbus is crash-proof and can cope with less skilled pilot than standard is misperception, promulgation of which is the fault of Airbus propaganda department...

Er, no - The AI marketing department set out their stall as saying that the A320 generation were *more protected* from getting into a dangerous situation than previous generations of airliners - and...

The probs is that Airbus planes (with all their rings and bells) were announced (or believed) to be protected of crashing .... you know .. like the Titanic can't sink ...
Pure arrogance ......

...it was the press of the time that paraphrased AI's claim of better protection as "it is impossible to crash this airliner", because it made better copy and - as laymen in aviation terms - they could not discern the subtle difference. It is true that Ziegler was something of a loose cannon in this regard, but I don't think that his word would have been the official company line. As an aside, it's interesting you mention the Titanic, as the phrase "practically unsinkable" was also an invention of the press (In this case "Shipbuilder" magazine), and not the official line of either White Star or Harland & Wolff.

Ziegler said to the press in a interview:
"This aircraft (Airbus) can be controlled by my concierge"

Did he actually say that his concierge wouldn't be able to crash it?

There are just as many "incidents" [maybe more] now as in the past.

But how many more airliners are flying worldwide *every day* than there were then?

Those of us who experienced this unsettling anomoly, would speculate that maybe the software engineers just never envisioned someone operating at over 250 knots below ten thousand.

So why didn't you tell them? Nothing us software engineers like more than fixing a problem!

And I take exception to use of the word "questionable" to describe the work done by AI's software engineers. I was privileged to learn from first-hand information (thanks to my Software Reliability lecturer who consulted with AI) just how much work went into specification, testing (both in the labs and in the air) and providing several measures of redundancy at multiple levels. I also know that they were happy to listen to any reports of a problem and work themselves silly trying to isolate and rectify it.

When Airbus flooded the market, a lot of us worried about the composite airframes but our suspicions about an aging vertical fin for example, inspected by an outsourced low-cost maintenance provider was dismissed as Old School paranoia. ... Next thing you know, one breaks up over new york and the pilot is blamed for using the rudder. A memo comes out telling me not to use the rudder if I can help it! :rolleyes:

Here we go again... It has been proven that the vertical stab failed at a point way beyond it's ultimate design load - i.e. it handled far more strain than it was designed to take, so I think that fatigue caused by ageing composites can quite easily be ruled out in that case. More on your first point shortly.

Could you miss the mountains in a pull up with this type of g-limiting and bank-limiting A320 FBW sidestick?
No, I don't think you can.

I beg to differ, but for starters - how close are you to the mountains?

FADEC will slow spool the engines to save TBO but hit the trees as it did in Toulouse.

Again, the digital automatic engine controls were *shut off irreversibly* by deliberate pilot action - they were under full manual control by the time they crossed the threshold and neither FBW nor FMS had anything to do with it.


But that went over about like a fart in church with the standardization mafia. "I needed to get the Airbus Religion" I was told when I objected to the classification of hand flying as "John Wayning" the airplane. They wanted me to use all these nanny protection devices all the time.
And here I go back to your point earlier. Was this in your company? If so then you have a simple pattern to follow; get together with a few like-minded people to put your concerns to the Chief Pilot - if he doesn't listen then the next step is the regulator via your union. If they don't listen then contact the manufacturer directly. This will eventually put you in danger of becoming a whistleblower - which could harm your career - but you'll at least be able to sleep at night knowing that you did everything you could.

What bothers me about a lot of posts in this thread is the number of anecdotes about how the management at some airlines are reluctant to consider potential failures in automation and "encourage maximum use of automation at all times". This is not a fault with any manufacturer or design, but a management failure at the airlines concerned.

I'm pretty sure that the engineers at AI (and for that matter most if not all manufacturers) would be happy to hear from pilots about any issues relating to the product, because at the end of the day their reputation gets tarnished if there is an accident.

To clarify - almost everyone reads the front page stories about an airliner crash when speculation is rife and no-one knows much of anything, but significantly fewer read the bylines months or years later when the actual cause is determined and reported. The result of which is that some people still believe that (paraphrased) "The computer thought the plane was trying to land" (Habsheim), "The composite fin attachment lugs were weak and therefore failed" (AA587), "A missile streak was seen before the explosion" (TWA800) and "The aircraft was on fire before it hit the ground" (too numerous to mention!)

but just like digital home computers, corruption may be lurking.

I've gone into this before and taken several paragraphs to do it, so I'll keep it to the piston-engine analogy I used then. Computers in the aviation realm are like the engine in your old pick-up truck - by which I mean they are specified with reliability over long periods of time as the paramount concern, designed and engineered using older, proven technology and given multiple layers of redundancy as a backup. Home computers on the other hand are more like an F1 racing engine - specified to run as fast as possible, designed using the latest bleeding-edge developments - and as such it is expected that they will only run for a (comparatively) short time before something goes wrong and they will require restarting.

Phew! Sorry to go on so long guys, but as I've said before the amount of misunderstanding on this subject saddens me a great deal. I'd like to add that clearing up such misunderstandings are my only intent here - I'm not especially pro- or anti- any aircraft manufacturer and don't want to get drawn into the bunfights that ensue.

My lifelong love of aviation means that I do a lot of reading on the subject and (as ex-ATC) I'd love to return to the sky at the controls again one day if my luck permits. However everything I have read, watched and taken in over the years has taught me that no manufacturer has ever been whiter than white when it comes to acknowledging faults in their product - though I'd say that both Boeing and AI have learned some lessons there in recent years and the result is some pretty damn good flying machines from both of them and from others.

I'm sure that the issue in the OP will be resolved swiftly, and I hope that one day we can put all this political garbage behind us.

[bearfoil]

AA695 Cali input one of two identical beacons broadcast from the ground. The one that would have them follow the coast south was not the one selected. The one (of two identical beacons) they selected put them into the granite. Let's be fair.

One rather famous AB developing engineer was heard to say (for the Press) "The Laundrywoman can fly this aircraft." One rather large knock on ABI is its permissiveness in allowing rumour and bunk (of the positive variety, natch) to proliferate without comment. Marketing is for seats, not aircraft, imo.

bear

[DozyWannabe]

AA695 Cali input one of two identical beacons broadcast from the ground. The one that would have them follow the coast south was not the one selected. The one (of two identical beacons) they selected put them into the granite. Let's be fair.

Again, as I understand it, not true. The beacon they were supposed to select was called ROZO, and to enter that directly they needed to input the whole designation into the keypad (i.e *R*-*O*-*Z*-*O*-*enter*). What they actually did, and in fairness to them their charts were not explicit, was input *R*-*enter* which switched them into a mode which listed all matching waypoints. They hit *enter* again, which selected the first on the list. Unfortunately the first on the list was not the ROZO beacon they wanted, but the Romeo beacon which was somewhere near Bogota if I recall correctly. The only reason this accident is not more prominent in the history of mode-confusion incidents is because the pilots then compounded the initial error by not paying close enough attention to what the aircraft was doing in response to the erroneous entry they had made.

Rightly or wrongly, the Cali accident is primarily attributed to the crew's failure to properly monitor the aircraft's progress once the incorrect input was made. To my mind, if they had paid more attention in that regard, the "What's it doing now?" cry would certainly have gone up.

One rather famous AB developing engineer was heard to say (for the Press) "The Laundrywoman can fly this aircraft." One rather large knock on ABI is its permissiveness in allowing rumour and bunk (of the positive variety, natch) to proliferate without comment. Marketing is for seats, not aircraft, imo.

So now that's 3 different versions I've head of this story, attributing ability to fly the A320 to a maid, a concierge and a laundrywoman. Does anyone here actually have a confirmed, attributable quote, or is this a case of chinese whispers?

At any rate, most attribute the quote to Bernard Ziegler - who was most certainly not an engineer of any sort on the product (us engineers tend to be a pernickety lot, because we're the ones with our arses on the line if we make unverifiable claims that later prove incorrect - whereas sales guys are expected to add a little merde du vache), and as I said above I have yet to hear a version of the story where he specifically said that the maid/concierge/laundrywoman would not be able to crash the aircraft. I don't think even Ziegler, controversial figure that he is, would have gone that far.

[DozyWannabe]

Bernard Ziegler was never sales or marketing, although he fancied himself at it.
I have a feeling he was what we would call a "product evangelist" in this day and age. Even so, he was still no engineer.

But remember that it was allowing loose canons to express themselves that gave Airbus the marketing edge in the 1980s & 90s.

Hmm... not sure. I'd say that Habsheim and the resulting backlash probably undid a lot of the confidence initially inspired by that tack. I think (and I've had some agreement) that what allowed AI to go from a single wide-body type offering to going toe-to-toe with Boeing - and successfully come out on top occasionally within a decade - was the unprecedented degree of flight deck commonality across the FBW range from the narrow-body short-medium haul A320 all the way up to the wide-body long-haul A340 (and later A380) - reducing conversion training costs by a significant margin and by extension making it easier for independent airlines to start small and expand to long-haul operations at a much lower cost than was previously possible, as long as they bought Airbus aircraft to make that expansion.

I say this as a non-business person (and with 20:20 hindsight), but I believe that Boeing missed a trick when they decided to develop the 737NG as they did - they'd made major advances in flight deck commonality with the 757 and 767, and they could have extensively reworked the 737NG to become part of that progression (and capitalised on the 737's enduring popularity at the short term expense of commonality with the Classic and Jurassic, and associated training and conversion costs).

Unfortunately the 737's popularity worked against that idea, because there were more Jurassic and Classic 737s in service than 757s and 767s combined. As such the NG was an extensively re-engineered beast compared to its elder brethren - and in many ways thoroughly modernised, but conversion across Boeing's product range was still more complex and expensive than what AI had to offer. As such it could almost be argued that Boeing became the victims of their own success, as the very ubiquity of their best-selling short-haul airliner forced on them difficult business decisions that AI, working from a clean sheet in terms of short-haul airliner design, didn't have to worry about.

[DC-ATE]

iceman50 -
Luddite - One who opposes technical or technological change.

Can't argue with you on that. It hasn't always been for the better though, has it?!

[DozyWannabe]

Can't argue with you on that. It hasn't always been for the better though, has it?!
I'll back out of this discussion after this post (realise I've been on this thread a lot in the last 24 hours), but I think that in most cases it has. Take that argument to the extreme and we'd still be nomadic hunter-gatherers hitting each other over the head with rocks!

More seriously though, I think that most technological advancements end up being for the better in the long term, though many either had growing pains, or were used for less salubrious things before coming right (e.g without the V2 rocket, humans might never have walked on the moon). I suspect what you're talking about is that technology has changed the nature of the profession you once held in a way you don't particularly care for, and you're not alone in that amongst people of almost every trade and profession, let alone just pilots!

[DC-ATE]

DozyWannabe -
I'll back out of this discussion.....

I will also being as how I'm an "inactive" Pilot now and merely looking back [as well as forward wishing things would go better for you all], at what was working pretty good.

Enjoy, and good luck.

[Razoray]

I just watched Nova's show on AF447. And although nothing new was brought to light they concentrated on the question of modern aircraft being over sophisticated and pilots becoming reliant on automation and loosing hand flying skills. They also mentioned that modern air flight simulators could not reproduce authentic situations to practice some evasive measures. They finished thier conclusions that the AF 447 pilots may have become overwhelmed and didn't take care of "flying the plane..."

That is when it hit me. The argument should not be about too much automation, or Airbus vs. Boeing, but about proper, or improper training......when pilots are in deep **** they need to rely on their training....but if the training is not there to match the situation.....everyone is screwed!

It's their "use the force" moment!

[CONF iture]

DozyWannabe

"Le 320, même ma concierge pourrait le piloter" is a formula from Bernard Ziegler.
It was at a time when the faith in the technology was absolute, the computers were there to correct the mistakes made by the pilots ... The formula understandably was not eared anymore in Toulouse after the 330 crash at the hands of the chief test pilot in 94.

Bernard Ziegler, known as the father of the 320, did graduate from Polytechnique and Supaero, don't you think he was an engineer ?

How can you pretend to clear up misunderstandings when you demonstrate so many yourself :

The register of the protections for a 320 are certainly not limited to the bank and the alpha floor.
Where does Airbus approve the possible necessity to have to switch off, on the pilot call, flight control computers ? Do you want to quote a QRH or FCOM procedure ?
Habsheim : Thrust was manual, does not mean that each FADEC was not performing his own engine management.

[jcjeant]

Hi,

Bernard Ziegler was firstly a pilot who killed 6 peoples as he was flying in a forbidden aera

France: Death in the Cathedral - TIME (http://www.time.com/time/magazine/article/0,9171,872735,00.html)

In August 1961 the Vallee Blanche Aerial Tramway (http://en.wikipedia.org/wiki/Vallee_Blanche_Aerial_Tramway) was badly damaged when an aeroplane of the French Air Force piloted by Bernard Ziegler tore its hauling cable. Three cars crashed and six people were killed.[1] (http://en.wikipedia.org/wiki/Bernard_Ziegler#cite_note-0)For more you can read the complete story of this "Airbus evangelist" ...there: :)
Bernard Ziegler - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Bernard_Ziegler)

. As a test pilot, he flew the first flights of the Airbus A300 (http://en.wikipedia.org/wiki/Airbus_A300), A310 (http://en.wikipedia.org/wiki/Airbus_A310), A320 (http://en.wikipedia.org/wiki/Airbus_A320_family) and the A340 (http://en.wikipedia.org/wiki/Airbus_A340).Airbus cowboy Bernard Ziegler - Airmail Magazine (http://www.airmailmagazine.com/airbus-cowboy-bernard-ziegler)

DoozyWanabee

Originally Posted by jcjeant http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/viewpost.gif (http://www.pprune.org/rumours-news/433616-airbus-prepares-safety-warnings-following-a321-incident-post6062186.html#post6062186)
Ziegler said to the press in a interview:
"This aircraft (Airbus) can be controlled by my concierge"
Did he actually say that his concierge wouldn't be able to crash it?So .. we can conclude than only the pilot can crash a Airbus .. the plane is out of all blame :)

[vapilot2004]

"Cowboys d'Airbus" by Bernard Ziegler

Tex Johnson with a taste for the fromage et vin?

[CONF iture]

Fargoo
How many reset on FAC1 have been done for your video sequence ?
Is it something like 0.9 degrees increment per reset ?

[DozyWannabe]

jcjeant:
He was a decorated military pilot before he got too cocky and caused the Alps accident. He has also not worked for AI since 1997 IIRC.

All I'm wondering is if anyone will ever realise "Le cheval que je flagellé, il est mort".

[kwateow]

Indeed. BZ is now an elderly and somewhat frail gentleman.

Lay off please.

[Fargoo]

Fargoo
How many reset on FAC1 have been done for your video sequence ?
Is it something like 0.9 degrees increment per reset ?

It's approximately 0.1 degrees per reset and always to the right , I was hoping you would hear the click of the switch each time but the camera mic wasn't sensitive enough over all the other background noise.

[320 driver]

Captain Crunch

Could you miss the mountains in a pull up with this type of g-limiting and bank-limiting A320 FBW sidestick?
No, I don't think you can. FBW will save the airframe from overload first, but ultimately hit the rocks as I understand it. It will reject the pilot's command to pull say seven g's. FADEC will slow spool the engines to save TBO but hit the trees as it did in Toulouse. Flying around on Alpha mode on the back side of the power curve is insane below ten thousand feet but simulator gods, test pilots and check airman seemed unconcerned about fostering such a dangerous habit when we first got the airplane.

I am honestly dumb-struck at your ignorance of your own subject.

Higher g will only offer advantage in the first few metres of a pull-up, the ability to pull max alpha will give more advantage in almost any conceivable GPWS scenario, something which is much, much easier in an alpha protected FBW type. Numerous studies have shown that such aircraft will massively outperform conventional types in GPWS pull ups.

If you pull seven g then you don't need to hit the mountain, you will have destroyed your aircraft all by yourself.

No-one to my knowledge has ever 'fostered the habit' of flying on the back of the curve at low level (and I have been flying this machine for 16 years). It is a facility that can be useful in certain unusual situations. Flying the aircraft at SOP speeds (O, F, S) keeps you right in the flat part of the curve. If you are operating on the back of the curve then it is your poor practice, not a defect of the aircraft, its makers or its operating philosophy.

FADEC does not slow spool the engines to save TBO. It does so to avoid surge/stall. All large fan engines are slow from idle with or without FADEC. FADEC just makes the acceleration safer and more reliable.

[CONF iture]

If you pull seven g then you don't need to hit the mountain, you will have destroyed your aircraft all by yourself.
In given circumstances, 3G or even just 2.1 or 2.6 could be all it takes to avoid ground contact ... too bad the electronic will not approve the request.

Pardon my ignorance but why do you associate G meter and alpha max ?

[320 driver]

the advantage of pulling an extra 0.1 or even 1.0g is miniscule and only beneficial if the obstruction is within a few metres of the aircraft when the maneuvre is initiated or the A/C is at very high speed. Overwhelming majority of GPWS incident are at low/medium speed. Modern GPWS will provide hard warning well outside the envelope where g is likely to be more useful than alpha performance.

The advantage of being able to accurately pull max alpha is huge and much more likely to prove beneficial.

I don't think I associated g meter and alpha. The point of my post is that they are separate and one (the one that A320 allows you to utilise much more effectively) is much more useful than the other.

[Admiral346]

To add:

It will reject the pilot's command to pull say seven g's.

http://upload.wikimedia.org/math/b/4/f/b4f4484d4017399578749c0442f17a11.png where:
Vst = stall speedVs = stall speed of the aircraft in straight, level flightn = load factor
So for a stall speed of 100 kts you get

Vst = 100 * sqr7 = 100 * 2,65 = 265 kts

So yanking 7g will not only break the wings off of any airliner, you'll most likely stall it and hit that mountain.

As explained above by 320driver to maintain alpha max will give you the maximum of achievable lift over the entire escape manouver.

That is also the reason, why the bank angle is limited to 66 degrees - flying a level, 66deg bank turn will result in 2.5g => which is the max gforce for which an airliner has to be designed for.

Nic

[Lonewolf_50]

The aircraft rolled to the left and adopted an approximately 10º left-wing-low attitude, without any flight control input from the crew. The flight crew reported that the aircraft did not seem to respond as expected to their control inputs and shuddered and jolted repeatedly.
First, a thought: if you make a control input and the aircraft does not respond as commanded, you are by definition in "out of control" flight ... so technically, the crew in this incident had a short excursion into "out of control" flight.

Curious regarding reaction from the pilots to this uncommanded control input from the robot.

When I was flying fleet helicopters with complex AFCS, the typical immediate action response (NATOPS BOLD FACE etc) was that uncommanded flight control inputs required immediate disconnect of AFCS, (don't consult the checklist, do it!). IF SAS or Boost was giving you spurious input, (AFCS being off, and the heirarchy being what it was) dump them as well until spurious input ceased.

As I read this report, the crew's reaction was similar but different. It appears that it took them a while to work through the "what's it trying to do now" and I gather that the intermittent nature of the fault drove that.

Am I following correctly? (Nice to be at 36K and have the luxury of time to work through a problem). :)

Unhooked - I recall hearing about an incident with a A340 out of MRU where the AOA vane was damaged in the stand and went unnoticed or unreported. ... I think the fast thinking commander switched off some of the PRIM's & SEC's (primary and secondary flight computers) and managed to return in direct law.

Fly the plane ... and disable any systems interfering with your flying the plane. Important point on that is that you really have to know your systems to ensure you know what does what ...

wiley - Complex systems fail in complex and often unanticipated ways.

Which is part of the problem of the "magic airplane" design philosophy.
You create X problems when you use robots to solve Y other problems. The only defense the crew have is expert and in depth system knowledge, and a robust continuum of training.
Clandestino - ... that Airbus is crash-proof and can cope with less skilled pilot than standard is misperception, promulgation of which is the fault of Airbus propaganda department, not the fellows who designed the Airbi.

Woe to the airline whose training department takes this sales pitch to be true.

Compared with a couple of decades ago, modern pilot has replaced: pilot, flight engineer, radio operator and navigator. Creating better and easier to operate systems was meant to decrease workload. It succeeded yet the intention was not to make life in cockpit easier: it was to reduce workforce as much as possible. It is all fine and well as long our electronic little helpers do their work. When they pack up, you have two people doing the job that was historically split between 4 to 6
Good point. Made a similar observation a few days ago, how complex aircraft and reduce crew actually up the requirements and demands on the crew. I found when doing crew training that any two man crew can eventually reach task saturation. (I had an evil reputation as a sim instructor, I confess! :E I liked to find crews' limits with multiple system malfunctions / emergencies ... unscripted.)

stev - A lot of the incidents of recent times have come from lack of knowledge of what the system is doing. Much of what Airbus tried to eliminate in the making of the A320 has been taken care of in the major developments of teaching of the modern elements of CRM. Leaving it to the computer may not be ideal.

Rananim seems to have a sound philosophy on that one.
rananim - I believethe airbus peole were well-intentioned and produced a landmark machine but the over-confidence was sickening...I like it this way.Monitor me,warn me but give me control.always.

Next thing you know, one breaks up over new york and the pilot is blamed for using the rudder. A memo comes out telling me not to use the rudder if I can help it!


Which brings us back to the incident in question.
From the report, it seems the rudder was being commanded (by other than a pilot) to do something that it should not have been doing. I will guess that perhaps -- and perhaps not -- the limitations in rudder control defelction were being respected by the robot (or not???) even though the robot, thanks to some dirty trons, was moving the rudder when it shouldn't. Different logic/control loops? :confused:

That is my layman's way of trying to decipher which protections may or may not have remained when one (of many channels) in the automatic flight control system went wrong.

It looks like the crew approached this malfunction in a rational, unhurried, and professional manner and got the bird to where it needed to be: on the ground where the electron chasing magicians would investigate and remedy the fault. :ok:


My surmise is that the robot will find another way to challenge a cockpit crew in unexpected ways in the not to distant future.

May it not happen close to the ground.

[320 driver]

Lonewolf

in the AA New York accident the rudder was being solely manipulated by the pilot. It was pilot error that generated the rudder input. The system had nothing to do with it.

[screwdriver]

A320Driver
At last the voice of common sense.

I am honestly dumb-struck at your ignorance of your own subject.

Higher g will only offer advantage in the first few metres of a pull-up, the ability to pull max alpha will give more advantage in almost any conceivable GPWS scenario, something which is much, much easier in an alpha protected FBW type. Numerous studies have shown that such aircraft will massively outperform conventional types in GPWS pull ups.

If you pull seven g then you don't need to hit the mountain, you will have destroyed your aircraft all by yourself.:)

[Captain-Crunch]

Interesting post by 320 driver. :)

I believe it aptly demonstrate my point about the "blind faith" some A320 drivers exhibit toward a design that over-rides the pilots command to miss the rocks since it's programed to instead save the airframe. The F-16 community went through a similar overconfidence in it's FBW introduction: that the airplane could get you out of any problem, with predictable fatal results. We're agreed then, that the studies of GPWS escape maneuvers at low altitude come into play AFTER Controlled Flight Into Terrain is avoided with an aggressive pull up, not before, in the scenario I refer to. I'm talking about a visual impact with hills due to a gross navigational error down low, and not spotted until too late. O.K, 7 g's was a lethal exaggeration. :} How about 3.5 G's? (thanks for the correction CONF iture).

Me? I prefer to bend the wings and miss the rocks, as was done on several aircraft that made it back alive due to the ability to temporarily exceed the design limits. I am aware of McDonald Douglas and Boeing events which were classified as accidents since the airframe was severely damaged in over-g pull ups. In Good Aerospace engineering, failure limit loads are not the same as operational limits, and have something like a ten to thirty percent additional protection before airframe yield occurs. Additionally, if an airplane is designed correctly, it will progressively fail, shedding outer structure before the spars completely fail.

I admit that I am completely ignorant how a profession pilot would worry about saving his airframe if rocks are looming in the windshield as they apparently were in Pakistan recently. Who cares about the airframe in this scenario? Miss the rocks at all costs, then, if you're still alive, hope you can limp back to the runway. But not in FBW as I understand it. In FBW you are not in command. The HAL-9000 is in command:

"I'm sorry Dave, I'm afraid I can't give you four g's right now, it might bend the titanium spar". BOOM.

Let me try to rephrase the question: Due to rapidly rising topography, if it takes say 3.8 g's immediate pull up in two seconds time to miss a rock outcrop and your A320 is given this command with full back stick, will it follow it?

No, it won't as I understand it. It will respect the load limit algorithm and only give you something like less than 2.x g's. Initially, in this case, the G limiting subroutine will overide any available angle of attack considerations.

Right?

Congratulations! We have saved the airframe for two seconds, but lost a hundred souls and the airframe in three!

Now I feel this is a design oversight. When I use that term or the term software`-shortcoming it's extremely upsetting to Dozy and others, however, it's not surprising. Aviation history is replete with design oversights. Don't worry Dozy, We are not blaming programmers (CEO's and flight management get that distinction), and besides, the event we're discussing is extremely unlikely an occurrence. But if it happens and you need say 80 degrees bank to miss the rock cliffs, you better pray you're in a Boeing.

By the way, I like FADEC, and it does do a great job most of the time (except at Heathrow with the dual "roll back" on final with the BA 777 and on dozens of airbuses over the years.) :* However, sometimes FADEC can't accelerate at it's full potential: if the airbus is in Level Change the FCP schedules a slow-spool up for pax comfort/tbo etc, and hits the trees, because:

It doesn't know the whole flying picture.

Only the pilot flying knows that. And only if he's not lulled to sleep riding around on autopilot watching the pfd FMA clicking through mindless modes that don't really keep the pilot informed as to what's happening unless you're staring right at it all the time. Which is why way back in 1995, AW&ST concluded that Airbus automation actually increases pilot workload, rather than reducing it as was advertised.

For me on the A-310's the answer was massive consumption of coffee making me a nervous wreck since I never knew when the damn thing was going to attempt a tail-slide or turn the wrong way, which it always did. It was like a bad student who had to be constantly watched. :suspect:

Admiral and others are correct, 7 g's is GA stuff, my bad.

320 driver said:
No-one to my knowledge has ever 'fostered the habit' of flying on the back of the curve at low level (and I have been flying this machine for 16 years). It is a facility that can be useful in certain unusual situations. Flying the aircraft at SOP speeds (O, F, S) keeps you right in the flat part of the curve. If you are operating on the back of the curve then it is your poor practice, not a defect of the aircraft, its makers or its operating philosophy.
320 driver, you seem unaware of the early history of airbus. For example here was an accident by one of the chief pilots resulting in the first A320 fatalities:

Air France Flight 296 was a chartered flight of a newly-delivered fly-by-wire (http://en.wikipedia.org/wiki/Fly-by-wire) Airbus A320-111 (http://en.wikipedia.org/wiki/Airbus_A320-111) operated by Air France (http://en.wikipedia.org/wiki/Air_France). On June 26, 1988, as part of an air show it was scheduled to fly over Mulhouse-Habsheim Airport (http://en.wikipedia.org/wiki/Mulhouse-Habsheim_Airport) (ICAO (http://en.wikipedia.org/wiki/ICAO) code LFGB) at a low speed with landing gear down at an altitude of 100 feet, but instead slowly descended to 30 feet before crashing into the tops of trees beyond the runway. Three passengers died. The cause of the accident is disputed, as many irregularities were later revealed by the accident investigation. This was the first ever crash involving an Airbus A320 (http://en.wikipedia.org/wiki/Airbus_A320)

The official report states[1] (http://en.wikipedia.org/wiki/Air_France_Flight_296#cite_note-report-0) the causes of the accident were:
Very low flyover height, lower than surrounding obstacles.
Very low speed, reduced to reach maximum possible angle of attack (http://en.wikipedia.org/wiki/Angle_of_attack).
Engines idling during flight.
Late application of go-around power.This combination led to the impact of the aircraft with the trees.
The Commission believed that if the descent below 100 feet was not deliberate, it may have resulted from failure to take proper account of the visual and aural information intended to give the height of the aircraft.

[edit (http://en.wikipedia.org/w/index.php?title=Air_France_Flight_296&action=edit&section=3)] A320 operation anomalies

Third-party investigations into the crash dispute the official findings.[2] (http://en.wikipedia.org/wiki/Air_France_Flight_296#cite_note-crash-1) Captain Asseline asserted the altimeter read 100 feet (30 m) despite video evidence that the plane was as low as 30 feet (10 m). He also reported that the engines didn't respond to his throttle input as he attempted to increase power. The month prior to the accident, Airbus (http://en.wikipedia.org/wiki/Airbus) posted two Operational Engineering Bulletins (http://en.wikipedia.org/w/index.php?title=Operational_Engineering_Bulletin&action=edit&redlink=1) indicating anomalous behaviour noted in the A320 aircraft. These bulletins were received by Air France but not sent out to pilots until after the accident:
[edit (http://en.wikipedia.org/w/index.php?title=Air_France_Flight_296&action=edit&section=4)] OEB 19/1: Engine Acceleration Deficiency at Low Altitude

This OEB noted that the engines may not respond to throttle input at low altitude.
Air France Flight 296 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Air_France_Flight_296)

Also, you might want to read up on the recent splashdown of an A320 in Europe, and the dozens of alpha mode mishaps and accidents on the A300/A310's if you are unaware of them. Everybody and every property produces different flying experiences, I'm sure. But the cult of a "magic airplane", as another poster put it, used to be a big part of airbus culture and was dangerous imho.

Studies have shown, that humans are very poor at monitoring automation. Although man does not live by hand alone, hand flying proficiency is essential imho to avoid all these coupled disasters that plague the industry. If you hand-fly you actually reduce crew workload and increase safety imho. If you operate as well, with manual thrust, you are better prepared for unexpected events like AF447 when, at dark of night, outto drops out and throws it all in your lap . But how do you retain hand flying skills in an airplane which calculates your bank angle and back pressure for you, and just when you need it most falls into manual law?

CC :)

[glad rag]

read up on the recent splashdown of an A320 in Europe,

I'm sure the families of the deceased will appreciate your flippancy and inaccuracies.

[hetfield]

For me on the A-310's the answer was massive consumption of coffee making me a nervous wreck since I never knew when the damn thing was going to attempt a tail-slide or turn the wrong way, which it always did.Sorry C.C., what are you talking about?

Thx

[Locked door]

Captain Crunch,

How on earth do you attribute the BA777 dual rollback to the FADECS? The power loss was caused by fuel starvation due to ice in the fuel/oil heat exchangers. Your accuracy with this is as good as your Airbus knowledge. :ugh:

FWIW (8000 hours, 50/50 Airbus / Boeing split), I much prefer the airbus GPWS pullup manouever. Give me max back stick compared to 20 degrees nose up any day. The Airbus climbs way way quicker. If you are ever in a situation where overloading the airframe in 'G' is the only thing that will save you then you should not be flying any aircraft, let alone a passenger one. If you ever want to see how fast an Airbus can pull up, watch this video.

YouTube - Airbus radical departure , Decolagem louca (http://www.youtube.com/watch?v=kK1wgwYKkrs)

I think there should be a forum rule, you can only comment on the Airbus once you have passed a type rating on one. Same for Boeings.

LD

[vapilot2004]

in the AA New York accident the rudder was being solely manipulated by the pilot. It was pilot error that generated the rudder input. The system had nothing to do with it.

On AA's A300's there is no data input from the rudder pedals. The DFDR records rudder movement only. Because the FO was the PF, it was assumed that the rudder was moving on his command.

Also, the DFDR traces were such a mess, the NTSB never published the raw traces and they had to cook the data in order to make any sense of it. This is partially due to the type of recorder the aircraft was equipped with which sampled rudder position at a rate of 2 points per second. Those units were later de-certified.

I am not summarily condemning the A300 in this accident, however I can say with confidence that the investigation was not among NTSB's finer moments.

[DC-ATE]

I think there should be a forum rule, you can only comment on the Airbus once you have passed a type rating on one.

Ha...I can just imagine a type rating on a Bus. You probably have to learn how to type: ASDF ;LKJ, etc. Have they got CONTROL/ALT/DELETE on those things?

[Locked door]

Which is just the typical biased, unthinking and ill informed prejudice my suggestion would stop!:ugh:

It's just another aircraft. A tool to do a job. Boeing use FBW now too, they were just slower to catch on.

[goldfish85]

Could you miss the mountains in a pull up with this type of g-limiting and bank-limiting A320 FBW sidestick?
No, I don't think you can. FBW will save the airframe from overload first, but ultimately hit the rocks as I understand it.


I thought so too. Back in the late 80s, I got into a lengthy argument with Gordon Corps, an Airbus test pilot. I suggested a contest. We would each dive at the ridge, and when I said "Now" we would each pull, me at slightly under the 3.75 g ultimate and he at 2.5 g. Whichever one missed the ridge would win.

What I didn't realize (and Airbus didn't explain well) was that he could snap the stick back to the stop and get to 2.5 g's right now. I would have to ease the yoke back and would ultimately take a few seconds. Later ALPA promoted an evaluation and found that snapping the stick right back smartly actually had the airplane bottom out somewhat higher.

I've come to the conclusion that Airbus got that part right. In fairness to Boeing, while the limits in g's are "soft" they're hard enough that I think you'll get the same effect.

Let's all get over it. A well-designed envelope protection scheme really works. It's saved airplanes. In the twenty some years of commercial FBW, I don't know of any caused by g-envelope protection.

Goldfish

[captainsmiffy]

Is there a tie-in, the name 'Captain Crunch' and all this talk of CFIT?!!

Quote "It doesn't know the whole flying picture."

Had to laugh when I read the above since the all seeing, all knowing pilot in command 'knew the whole picture' but was needing a high G pull up! Surely he would see this coming and have acted accordingly if he was that switched on....?!! An old instructor once taught me that he used all of his years of experience and cunning to stay well away from those situations that required him to actually use it!

A later poster hit the nail on the head when he said that the use of full back stick and very fast application of 2.5g was a winner from Airbus. I agree. If you haven't seen it, you should.

[South Prince]

Just another airplane! very complex. training and instructors at times not up to level required.

[DC-ATE]

It's just another aircraft. A tool to do a job. Boeing use FBW now too, they were just slower to catch on.

Hey, I don't like Boeing FBW either. Like I've said many times on here: I'm glad I'm out of this racket.

Why can't you young computer controled airline pilots admit that the manufacturers are trying to design you out of the aircraft completely with all this new "technology" that you speak so highly of? Don't think it can't be done. And...yes...people will eventually get used to the idea that noone is up there !! Will there still be accidents? Yes. But at least they will no longer be blamed on pilot error !! Then perhaps the cycle will start all over again with cable operated aircraft with real pilots and no computers.

[Safety Concerns]

what are you lot going on about. All Airbus FBW aircraft can be reduced back down to manual flying very easily. Not ideal though because the protections are there in the first place because you lot kept crashing.

Get over it. The technology is there as a result of your human failings and it works. Flying has never been so safe.

[411A]

Flying has never been so safe.
And yet, AirFrance seems to crash 'em with some regularity.:rolleyes:

[Locked door]

Yeah, but nothing is ever foolproof, because fools are so ingenious! :E

[CONF iture]

All Airbus FBW aircraft can be reduced back down to manual flying very easily. Not ideal though because the protections are there in the first place because you lot kept crashing.
If it was true it would show up immensely in the statistics ... is it the case ?

Beside that, what is manual flying if not FBW ... Please explain.
Do you think protections disappear when AP is selected OFF ... you have some reading to do here.

FBW is not the issue, protections are the concern.

Why can't you young computer controled airline pilots admit that the manufacturers are trying to design you out of the aircraft completely with all this new "technology" that you speak so highly of?
THAT is the key point.

[Clandestino]

Why can't you young computer controled airline pilots admit that the manufacturers are trying to design you out of the aircraft completely with all this new "technology" that you speak so highly of? Don't think it can't be done. Chill out, dude. My current steed has no autoland,yet somehow I manage to perform CAT IIIA ILS approaches manually down to 50ft DH with 100% success rate so far. Of course that automatics could replace me on that simple task yet they don't; I'm cheaper than autoland capable George. If the manufacturers were really trying to design pilot out of A/C completely, every machine out there would be epic failure.

protections are the concern.

For those pilots trying to bend the limitations or boldly going where no sane pilot has ventured before, yes. For the rest of the A-brand pilot population, not so.

If it was true it would show up immensely in the statistics ...

What is your definition of immense show up when we're discussing the statistics of small numbers?

[320 driver]

From Captain Crunch

We're agreed then, that the studies of GPWS escape maneuvers at low altitude come into play AFTER Controlled Flight Into Terrain is avoided with an aggressive pull up, not before

?????

Were you 'tired' when you wrote this. How can GPWS escape maneuvres come in to play after we have avoided terrain? Sorry to state the obvious but GPWS maneuvres are FOR avoiding CFIT. Being able to pull 3.5 instead of 2.5 g in an 'old' aircraft is of no benefit whatsoever for the following reasons:

1. The difference in clearance is in the order of a few feet over a period of a fraction of a second, the FBW aircraft will offer more clearance with its alpha prot in almost any recorded or likely GPWS event.

2. Your assertion assumes that your 'old' aircraft is being flown by a pilot who can accurately pull instantly to 3.5g and no more. If he pulls 1.0g less you have lost your benefit, if 0.25g (the standard margin) more he has folded your wings. He will alos have to apply full control deflection until the required g is achieved and then accurately sustain it for the second or so before he stalls.

If you really believe such a pilot exists and is therefore likely to be able to get a better GPWS maneuvre from a conventional aircraft than a FBW type then I can only marvel at your innocence.

FBW alpha prot gives better GPWS performance.

[oldchina]

In addition to being technically correct, you're exceptionally polite to the dinosaur community.

[CONF iture]

For those pilots trying to bend the limitations or boldly going where no sane pilot has ventured before, yes.
Which limitation did they try to bend on QF72, please remind me Clandestino.

What is your definition of immense show up when we're discussing the statistics of small numbers?
Why don't you question SC ... He wrote that 'the protections are there in the first place because you lot kept crashing'
Can you produce figures that would support such statement ?

The difference in clearance is in the order of a few feet over a period of a fraction of a second, the FBW aircraft will offer more clearance with its alpha prot in almost any recorded or likely GPWS event.
Once again, G load protection and alpha prot are two different things.
If the XL Airbus in Perpignan don't follow the pilot request in the final dive, that's because of the G load protection to make sure that the aircraft is intact up to the crash site. BEA and Airbus did not publish that key G load graph ... any reason why ?

[nilcostoptionmyass]

ahh yes, alpha prot will save us....

If i'm on my 'dinosaur' aircraft flying at 330kts and want to pull up to 60 deg up and wash the speed off, i can, because i.m in control.

The 'scarebus' won't let you pull more than 30deg up from the horizon ?, nothing to do with the AOA ??

OEB's ? the thing that the airbus 'tech guys' publish in the back of the QRH because they can't be bothered to fix the problem.

Checklists that are half ECAM / half paper.

Fmgc's that dump the flight plan because they 'think' they have landed, because you flew to 'near' the airport.

Landing calculations, the like of which no one has ever seen before, multiplying this percentage by that percentage but only if icing with flap 3 landing otherwise multiply by 8% + landing correction and add it to the landing distance required if all is ok.

And all while the other bloke might be handflying ??

Returning to subject, is there not an 'OEB' for sparking generator plugs causing half the electrical system to 'flicker' ?

:ugh::ugh:

[Captain-Crunch]

Great post Goldfish85,

Exactly the real-world insight I was trying to tease out with my remarks. Direct experience, not just as line pilot, but emergency pull-up with a A320 test pilot from the manufacturer.

So if I understand the scenario correctly,
this ridge-targeted-pull-up contest was done with level wings level?

The reason I ask, is that if you were in constant altitude 60 degree bank, you are already pulling two g's, right? If you "snap back" full aft stick in the 60 degree bank what will the A320 FBW give you? Point two G's over level? (0.2 g?)

Now try this in a stone age 737. Sure, it's likely to momentarily reach critical angle of attack. But you might be able to recover from stall after you clear the ridge. Even if you don't clear the ridge or recover from stall, you might survive a full stall impact, whereas you have no chance with one way above shaker that's stopped your FBW pull up due to an operational g limit. So I'm still not convinced of the superiority of FBW in this case.

In other words, I am still under the impression that a hard, for example, operational 2.2 g "snapback" limit will not prevent missing a rock outcrop that requires say 3.5 g's to clear it.

How can GPWS escape maneuvres come in to play after we have avoided terrain? Sorry to state the obvious but GPWS maneuvres are FOR avoiding CFIT. @ 320 driver,

My traditional perception of true CFIT means that there is nothing wrong with the airplane, that it hits the first rock outcropping with the crew and aircraft in control and unaware they or ATC screwed up until it is too late. GPWS escape maneuvers mostly came out AFTER the CFIT term was coined (FTL flight 66). Once a GPWS escape maneuver is commenced, the crew is really out of control, in my opinion, as they are uncertain of their navigational position and/or safe altitude and are engrossed in an unexpected emergency "Hail-Mary" that may or may not turn out well.

I was discussing a scenario in which the objective is missing the very first rock outcrop only; whereby once accomplished, the rest of the escape maneuver to miss secondary high obstacles is a different subject (in which airbus alpha mode would be superior if you live to see it.) I was trying to focus on the very first lethal ridge and whether or not FBW can out-G conventional controls.

I am sorry if I was not being clear.

CC

[Captain-Crunch]

"Locked-door" said:
How on earth do you attribute the BA777 dual rollback to the FADECS? The power loss was caused by fuel starvation due to ice in the fuel/oil heat exchangers. Your accuracy with this is as good as your Airbus knowledge.CC says:
I've read the 777 thread and I know that ice all by itself is blamed for the accident. But I just don't buy it. Thousands of jet engines with fuel/oil heat exchangers have operated in icing temperatures all over the world for fifty years and I've never heard of a single crash caused by all engines just sitting there in idle. Aren't trent engines certified? Aren't the heat exchangers required to have some sort of a emergency fuel bypass? (this would allow power up which would extinguish any engine fuel ice lights once hot oil re-entered the exchanger.) Haven't you ever done this on jets? Pulled up the boards and shoved the power up on descent to kill the ice lights? I have. Since the machine was dirty, it didn't need boards, just a pilot to disconnect ATS and manually advance enough power to heat up the oil.

But engineers stated on that thread that we don't know for sure that FADEC commanded a throttle up since data points were infrequent and maybe only plotted software commands outside of FADEC instead of actual FCU position. I'm not a software expert, but even I know that FADECs have a reboot subroutine that rolls the engine back to idle if certain anomalies crop up. Not only that, but a programmer there was claiming the A and B channels are identical code adopted (allegedly) to save programmer costs.

Ask yourself: how could both engines have enough fuel to remain in idle but not enough to produce partial power when commanded to? What are the odds ?

All I can fathom is that dual identical software bugs struck at the same time in the same conditions since the code is identical on both channels and identical on both engines. I'm told all performance is impossible to test before certification, since you're talking about millions of lines of computer code and exponential combinations of output. It might take ten or twenty years to test all the possible software decision trees. So they rubber stamp it and "finish it in the field."

An insane arrangement, but one that today's button pusher seems to have no problem with. An engine who knows better than the captain when to roll itself back or prevent a power up if expected engine and RPM values don't materialize! :rolleyes:

Again, we've saved the equipment and lost the airplane. :ugh:

What a concept!

Oh, Give me a steel cable connected directly to the FCU anyday!
(i.e, give me a way to turn the HAL 9000 off when it goes nuts).

Captain Dinosaur - out

By the way, I'm retired and all these are just my opinions only, and I could be wrong about everything.

..

[PBL]

I don't usually reply to ignorant commentary, because there is just so much of it. But there is ignorance, and then there is willful ignorance. Speculating in public on matters which are clearly dealt with in the existing literature is a disservice to anyone involved in or with this accident, including the investigators, and the engineers who worked on the airplane.

I'm not a software expert, .... All I can fathom is that dual identical software bugs struck at the same time in the same conditions since the code is identical on both channels and identical on both engines.


Yes, we can agree you are not a software expert. I am.

In the report, even preliminary reports, on this accident, it is clearly stated that the FADECs behaved exactly as intended and designed for the conditions with which they were presented. Even if there are anomalies somewhere, on this occasion they did not show.

you're talking about millions of lines of computer code and expotential combinations of output. It might take ten or twenty years to test all the possible software decision trees.

We are talking about some small hundreds of thousands of lines, not millions. If that code is DAL A, there is a certification requirement to exercise all decision branches: it is called MC/CD testing. I don't know whether the code was MC/DC tested but I can find out.

However, this does not suffice to test the code adequately. In fact, thorough testing is impractical. Far from "ten or twenty years", to reach the conclusion that there are no dangerous errors in the software would require testing for as long as or longer than the entire service life of the aircraft. It is impractical to reach a conclusion with any reasonable level of confidence through statistical testing that the software has a lower rate of failure than once every hundred thousand operational hours on average. This is a hard mathematical boundary, one with which critical-software developers have to work.

PBL

[Safety Concerns]

Let's all get over it. A well-designed envelope protection scheme really works. It's saved airplanes. In the twenty some years of commercial FBW, I don't know of any caused by g-envelope protection.

Agree totally.

The fact is there may well be one scenario out there where no protections is desirable but even if there was the protections have already saved literally thousands of pilots backsides already.

Many of you also have selective memory. Military jets have been FBW since the 70's. It works. I remember one smart arse who claimed the protections prevented him from displaying his full dog fight skills and so prevented him from saving the world. Yes he switched them off (as can be done on any FBW aircraft) and promptly ejected after losing control in his next battle.

Hudson river hero successfully landed his stricken A320 on a river. What more evidence do you non believers need to confirm that the design is sound.

And I quote the NTSB, page 88 by the way:

The NTSB concludes that, despite being unable to complete the Engine Dual Failure checklist, the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.

What is needed today are pilots like Sullenberger who gell and understand their aircraft rather than criticise because they probably don't understand the technology.

[Captain-Crunch]

Hey PBL,

Thanks for the great post. It's clear from everybody that my ignorance knows no bounds. :ooh: It seems like the older I get, the less I know. However that's why I make these posts, in order to learn. And speaking of learning; since you offered, I would in fact, be interested to learn if Trent FADEC code is MC/CD tested. I stand corrected then: it's not millions, but hundreds of thousands of lines of FADEC code that are used (however I was told, it isn't the standard commercial version, additional cross check blocks have been added.) Isn't it conceivable that certain paths could result in an unexpected "rollback" to idle? From previous unexpected rollbacks I know that the flight crew isn't part of this decision to kill engine thrust. Personally I'd rather have partial power or explosive power to get the machine safely to the TDZ and then just junk the engine (instead of a rollback). But that's just me.

However, this does not suffice to test the code adequately. In fact, thorough testing is impractical. Far from "ten or twenty years", to reach the conclusion that there are no dangerous errors in the software would require testing for as long as or longer than the entire service life of the aircraft. It is impractical to reach a conclusion with any reasonable level of confidence through statistical testing that the software has a lower rate of failure than once every hundred thousand operational hours on average. This is a hard mathematical boundary, one with which critical-software developers have to work.
Fascinating insight.

Thank you for your frank honesty (even if it takes a beer to put out the flames. :}) It's not easy being the point man for the Dinosaur Squad. You see, we dinos don't trust the goverment/industry to tell us the whole story. They've lied and covered-up so much in the past that taking an accident report at face value seems very foolish to many of us. It's more likely, considering human nature and liability, that they just quietly issued a new FADEC software"load" to fix the machines inability to deal with common ice in the fuel and upped the dia of the fuel lines.

And guys, sorry for the thread drift to 777 FADEC. Back to the subject, A320 shuttering in flight, PBL, I have another unfounded theory, since I'm not privy to any of the data beyond what I read here, that this A320 was severely cross controlled. Aircraft wants to go left with flight spoilers, but is confronted with excess right rudder introduced by a faulty centering solution every time power is interrupted. Plausible?

A friend told me:

the A320's most important flight control computers, the ELACs, each contain one Motorola 68000 and one Intel 80186 processor, which run the same algorithms, but I do not know if their software was developed by isolated teams. There are 2 redundant ELACs, and if they both fail, there are 2 SECs, which also provide pitch and roll control, albeit in a degraded mode (alternate or direct law.)
A question I have is does the roll logic know where the rudder trim is?

I'll betcha it doesn't. I'll betcha it just dumbly keeps feeding in more roll spoiler to counter the stronger rudder trim. The result is that the rudder wins, and a gross navigational error occurs. Not sure you can commend a computer crew who didn't disconnect this thing at the first sign of trouble.

But I wasn't there... they were probably fighting the ecam and paper check list from hell; so distracted, that nobody was flying the airplane, and I'll admit that many button pushers don't know how to trim the airplane for fastest mach, so the habit to disconnect and find out what's wrong just isn't there.

They have a: Severe Fear of autopilot disconnect ;)

Now, just let me don my flack jacket here....

CC
still on the ragged edge

[Captain-Crunch]

Captain-Crunch -

Great post. I'd be interested in knowing what you are, or were, rated on. Thanks.Hey DC-ATE, missed you post earlier, tried to private mail you but says it's disabled.

I lost my medical, but flew:

GA bugsmashers
Beech 18's (radial engines!)
Fanjet Falcons, B727, B747, BAe-146,
Typed on B-737, A300s/A310's, DC-10's
picked up an A&P for fun.

But it's all dino junk now, and I'm telling you I just can't get no respect. :E

CC

[windytoo]

It looks like you have missed out your last rating..... Rocking chair in front of breakfast TV.

[jcjeant]

Hi,

It looks like you have missed out your last rating..... Rocking chair in front of breakfast TV.
Methink it's a unwanted comment :=
Anyways pilot or not we will all obtain this rating :)

[CONF iture]

The fact is there may well be one scenario out there where no protections is desirable but even if there was the protections have already saved literally thousands of pilots backsides already.
Stop your fairy tell here Safety Concerns, or show me the thousands reports of pilots who could not be saved by lack of protections.

Hudson river hero successfully landed his stricken A320 on a river. What more evidence do you non believers need to confirm that the design is sound.
The Hudson outcome has absolutely nothing to do with the aircraft type, but everything with the decision making and the ability.
And ask Sullenberger what he thinks about his 320 that refused to flare the way he wanted to ...

[DC-ATE]

Captain-Crunch -
Hey DC-ATE, missed you post earlier, tried to private mail you but says it's disabled.

OK...thanks. Don't know why it would show disabled. Only the e-mail one is. No big deal.


Captain-Crunch -
Oh, Give me a steel cable connected directly to the FCU anyday!

I think we're both on pretty much the same track. Nice being out of all this mess, isn't it ?!?!

[PBL]

It's more likely, considering human nature and liability, that they just quietly issued a new FADEC software"load" to fix the machines inability to deal with common ice in the fuel and upped the dia of the fuel lines.

I see, a "conspiracy theorist". You are spouting off on something on which you confessedly don't know anything, and you want to doubt even the experts.

My view is derived not only from the accident report but also from someone who works with the engine manufacturer closely, who is an expert on critical SW, and who has been a respected and trusted colleague of mine for two decades.

I don't know whether that's enough for you. But it's enough for me. And I'm the expert.

PBL

[kwateow]

"ask Sullenberger what he thinks about his 320 that refused to flare the way he wanted to ..."
You're too subtle for me, but maybe that A320 knew what was the best amount of flare.

DC-ATE-Crunch: I also took cars apart and understood what they were made of.
Now I can't even see what's in there... But they're much better cars. And safer.

Imagine steel cables running to the far corners of an A380. Firstly they're so heavy that it wouldn't perform.
Secondly can you honestly say all on board the QF machine would be alive today if Airbus used 1950's design standards?

[Safety Concerns]

The Hudson outcome has absolutely nothing to do with the aircraft type, but everything with the decision making and the ability.
And ask Sullenberger what he thinks about his 320 that refused to flare the way he wanted to

What part of this text from the accident report don't you understand.

The NTSB concludes that, despite being unable to complete the Engine Dual Failure checklist, the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.


As there were no safety recommendations relating to the performance envelope software; work it out for yourself conf iture what is being said here.

Once you have you will realise that criticising FBW has more to do with misplaced ego than any design deficiency.

[p51guy]

Sully could have landed any Boeing with no automation in the Hudson with no problem. Airbus had nothing to do with his success. He was a very competent pilot and could have landed any type of aircraft in the Hudson with no automatic help. I think most of us would hope we could too. We just don't need the opportunity to display it like he did.

[CONF iture]

Safety Concerns
You would be welcome to quote me if I have ever criticized FBW … but do you only understand the difference between FBW and protections ?

NTSB report on US1549
Maybe there is a difference between maintaining the flight envelope protections alive and actually use it ... what do you think ?.
Where in the report, is it said that the protections took over to prevent the 'green' Sullenberger to stall ... Please quote !?

More on the Hudson Here (http://www.pprune.org/rumours-news/430184-a320-tailstrike-after-radalt-failures-2.html#post5988838)
To be in DIRECT LAW would have helped Sully, but once again, do you only understand what's the difference between DIRECT and NORMAL ... and yes, both are still FBW.


And please, don’t forget to quote the thousands reports that would support your earlier statement …

[DC-ATE]

kwateow -
DC-ATE-Crunch: I also took cars apart and understood what they were made of.
Now I can't even see what's in there... But they're much better cars. And safer.

Well, when they start making cars FBW, I'll quit driving too !

As to the 380.....there really isn't a need for that monster anyway. It's just one manufacturer trying to outdo the other IMHO.

[DozyWannabe]

Safety Concerns
You would be welcome to quote me if I have ever criticized FBW … but do you only understand the difference between FBW and protections ?

The protections are part and parcel of the FBW system if we're talking about the traditional separation between FBW, which relates to computer-assisted control, and FMS, which relates to a computer controlling the aircraft directly and is in effect simply the latest generation of autopilot.

Stability protection was the whole purpose behind the first generations of FBW anyway, as the military aircraft in which it was installed were inherently unstable and needed constant computer correction to maintain flight.

I don't think there's a single incident where the protections have caused a hull loss - at least not when there hasn't been a major malfunction.

Where in the report, is it said that the protections took over to prevent the 'green' Sullenberger to stall ... Please quote !?

Er, no-one was suggesting that... you made that one up on your own.

To be in DIRECT LAW would have helped Sully

Disagree strongly. Sullenberger had no need to place the aircraft in an attitude outside the protection boundaries, and I believe the protections were a useful backstop - a last line of defence against, say, a gust strong enough to cause the aircraft to bank - in much the same way as they've kept the wings level in earlier incidents.

In fact at no point has Sullenberger even hinted that the aircraft did anything other than what he asked of it (besides the obvious double engine failure due to birdstrike) and the link you provide only goes to your supposition in an earlier thread - and like it or not, the fact that you have an axe to grind with Airbus is well known.

Anyway, as I understand it the protections allow for up to 60 degrees of bank if the pilot commands it - much more and you risk a spiral dive.

[delta3]

Merc's Distronic+ cannot be turned off and has the last word in a number of situations. Although not full FBW, I am afraid you may have to quit driving somewhere in the future...

d3

[CONF iture]

Disagree strongly. Sullenberger had no need to place the aircraft in an attitude outside the protection boundaries, and I believe the protections were a useful backstop
Because properly flaring an aircraft is to "place it in an attitude outside the protection boundaries" ???
Strange definition for a flare ...

[Captain-Crunch]

PBL,
Well, even though I don't think it's a conspiracy, I noticed that most people who go around calling themselves "experts" are anything but that. :} Witness the so-called "Aviation Experts" touted in the popular press who frequently cannot answer basic questions about the accident aircraft. For instance, "expert", it sounds like you're not even sure which programing language is used on the trent FADEC system. Since you provided no links or quotes at all to back up your assersion that the investigative process is infallible, it appears to me you may making nothing but an:

Argument from authority (also known as appeal to authority) is a fallacy of defective induction (http://en.wikipedia.org/wiki/Fallacy_of_defective_induction), where it is argued that a statement is correct because the statement is made by a person or source that is commonly regarded as authoritative. The most general structure of this argument is:
Source A says that p is true.
Source A is authoritative.
Therefore, p is true.This is a fallacy because the truth or falsity of a claim is not related to the authority of the claimant, and because the premises can be true, and the conclusion false (an authoritative claim can turn out to be false). It is also known as argumentum ad verecundiam (Latin (http://en.wikipedia.org/wiki/Latin_language): argument to respect) or ipse dixit (http://en.wikipedia.org/wiki/Ipsedixitism) (Latin: he himself said it).
On the other hand, arguments from authority are an important part of informal logic (http://en.wikipedia.org/wiki/Informal_logic). Since we cannot have expert knowledge of many subjects, we often rely on the judgments of those who do. There is no fallacy involved in simply arguing that the assertion made by an authority is true. The fallacy only arises when it is claimed or implied that the authority is infallible in principle and can hence be exempted from criticism.
PBL, please state your background that qualifies you as an expert on the trent FADEC system, and if not that, exactly what kind of expert are you claiming to be? It has nothing to do with conspiracies. Accident investigations are inherently political by their very nature. Ambitious human beings write the reports. You made a claim that we should just trust authority that the FADEC did it's job, and to give your claim credibility I need to know how many years working on aerospace software you have. :)

That's a fair question isn't it?

CC

[PBL]

Captain-Crunch,

you are welcome to question my credentials. You are also welcome to check them out. My identity is no secret.

I guess I could mention a couple of recent developments that don't yet appear in the public record. Our textbook on computer-related system safety is almost finished in draft, and will be published next year by Springer Verlag. And I have recently been invited to join the German standards committee responsible for the functional safety of systems involving programmable electronic components in order specifically to develop guidelines for the application of the international standard IEC 61508 to critical-software development in Germany. This standard governs all applications other than aerospace and medical devices (there are also specific derived standards for other domains such as process control and railway systems). I am on the international maintenance team for the software part of IEC 61508.

Is that the kind of thing that would enable a layman such as yourself to agree that I am expert?

As for my colleague who vouched for the accuracy of the FADEC judgement in the BA038 report, you are welcome to guess who he might be, but will get no confirmation from me.

PBL

[PBL]

Well, when they start making cars FBW, I'll quit driving too !

Do you drive a car with Electronic Stability Protection (ESP)? Most new European cars have it. So do remember not to rent a car if you visit Europe.

PBL

[PBL]

I don't think there's a single incident where the protections have caused a hull loss - at least not when there hasn't been a major malfunction.

Yes, but please don't forget that Hamburg came very close!

PBL

[Captain-Crunch]

Very Impressive PBL,

Sorry to doubt your good word, but we get instant experts coming out the ears around here as I'm sure you can appreciate.

Although I was not asking for your identity, it appears your group is comprised of Ph.D's and has experience in accident investigation. I picked up a Computer Studies A.S. degree and studied for a time at an Aviation University and took courses in Aviation Safety and Accident Investigation so this sort of thing interests me. I later assisted in the preliminary investigations of a couple of accidents in our pilot union and my flight safety report (flameout in a typhoon) was used in the clearing of one crew of blame for an overrun accident. I'm not familiar with the language standard you maintain, but it sounds very interesting.

I suspect I could comprehend some of the FADEC architecture if I had access to it; but I'm sure it's proprietary. (not the physical code, but flowcharts would be interesting.) It would be interesting to know how the sw handles all fuel temp probes iced up. On AF447 it was clear to us on that thread that no one considered the possibility of all three airspeed probes and all static probes icing up at the same time. Rather than exercising a flight with unreliable airspeed strategy: N1 and deck angle, which pilots of most jets would employ, the software apparently biased out most of the backup systems according to the ACARS transmissions. In other words, the autopilot and auto throttle were incapable of operating with no pitot static system and abruptly dropped out throwing it all in the lap of the pilot on a dark and stormy night with partial panel.

This seems like a serious software design oversight imho, at least from a pilot's perspective. Arguments that it was approved and certified by experts really mean little if you are a student of Aviation history as I am. All designs eventually crash with any appreciable time in service.

If you ask me, adding more and more complexity to this automation monster we have created and keeping everything in extreme secrecy is what really does the industry a disservice imho.

KISS baby, KISS! (keep it sim...)

And I think it's best to realize that this is after all, a pilot's rumour network, not a tabloid for the public to read. Right? :)

Best Regards,

CC

[PBL]

Captain Crunch,

thank you for your gracious reply.

I suspect I could comprehend some of the FADEC architecture if I had access to it; but I'm sure it's proprietary. (not the physical code, but flowcharts would be interesting.) It would be interesting to know how the sw handles all fuel temp probes iced up. .....


You are right about design and code being proprietary. Your suggestion (flow charts, which no one uses any more as far as I know) concerns design. Then there is the coding. General industry knowledge (not of RR in particular; I have no specific knowledge of the quality of their SW and do not wish to suggest that I have) suggests that in delivered safety-critical SW one can expect about 1 error in about 1000 lines of executable code (LOC). State of the art for the last few years appears to be about 1 error in 25,000 LOC; that has been achieved in well-documented products derived according to a very strict and well-proven analytical regimen during development. So in, say, 150,000 LOC one would not be surprised to find between 6 and 150 errors.


If you ask me, adding more and more complexity to this automation monster we have created and keeping everything in extreme secrecy is what really does the industry a disservice imho.

A distinguished colleague of mine proposes that all safety-critical software in any domain should be published, by law, so that anyone is enabled to check and comment on the quality of the product. ( And of course to enable the usual army of computer-obsessives to find faults in it faster than the developer :) ) I think that proposal has a lot to recommend it. First, quality of product will be on public display, so the public will be able to make up its collective mind on a matter of public interest, namely safety of flight. Second, quality will likely improve.

Presumed-quality of SW has been for far too long judged by the process used to develop it, and not by objective properties of the resulting SW product. No correlation has been demonstrated in the scientific and engineering literature between the "usual" features of quality-of-process and the quality of the resulting product, except for those processes which explicitly involve determining objective properties of the product (such as the exclusion of possibilities of run-time failure). The goal of my standardisation work is to bring more focus upon evaluating properties of the SW product.


And I think it's best to realize that this is after all, a pilot's rumour network, not a tabloid for the public to read. Right?


It seems to be both of those, at least. And who am I to judge its purpose?

PBL

[DC-ATE]

PBL -
Do you drive a car with Electronic Stability Protection (ESP)? Most new European cars have it. So do remember not to rent a car if you visit Europe.

No, I drive a real vehicle; a 2000 GMC stretched YUKON. It doesn't need any of that cr*p. I live in the U.S., so it's very doubtful I'd ever buy any foreign automobile. And don't look for me to visit anytime soon as I'm too busy here.

[Fargoo]

To be honest most modern cars have some element of "FBW" with electronic throttle (gas) pedals. I'd be dubious of buying a car with FBW type steering or braking systems though given how often systems like ABS or ESP seem to throw a wobbler.

Anyway, back to aircraft.

[Atreyu]

Surely being equipped with EGPWS negates about 80% of the debate in this thread?

"Yellow represents a cautionary alert 60-seconds prior to the predicted time of impact and is accompanied by a "caution terrain" aural message. And red indicates terrain that the aircraft could impact within 30 seconds; it is accompanied by an aural "terrain, terrain, pull up"

Given at worst case you have 30 seconds until terrain contact, the Airbus FBW protections will have no impact on clearance of terrain? Or is that too simplistic a view for some on here? :E

Atreyu :ok:

[Locked door]

And therein lies the problem with a lot of the fine folks from the good 'ol US of A.

Never left the country, not willing to embrace other cultures, mind not open to other ideas, not willing to expand knowledge. Even if they have left the country they remain protected by the bubble that is their employer. I lived in the States for a year and the ignorance and insularism are quite astounding. No wonder you can elect presidents like Bush the Younger and possibly Sarah Palin! That's why I'm so nice to Yanks I meet outside the States, at least they've decided to take a look around.

Well I got some news for you, the rest of the world is playing and playing good. The only reason you buy a car from the 'States is patriotism, not for fuel efficiency, build quality, power, handling or looks!!! ESP is beginning to be incorporated in US cars, but guess what, it's made by Bosche, zee Germans!

There are certain contributors to this thread that if they were in charge of R&D for the human race would still have us waiting for lightning strikes to light our camp fires 'cos that's the way we've always done it' and are just about thinking that there's a better way of transporting stuff other than carrying it on our backs. Maybe you should go live with the Amish, I think you'd be happy there. :rolleyes:

Sorry if this sounds like an anti US rant, it's not, just get out and have a look how it's done elsewhere!

The problem with debating with such closed minds is that you can never win, even with evidence. They just won't see it.

Back in my box.

LD

[DozyWannabe]

Yes, but please don't forget that Hamburg came very close!

True, though I'd always considered that incident a configuration failure (false WoW switch/ground mode), and as such, something not peculiar to the Airbus FBW models...

[DC-ATE]

Locked door -
And therein lies the problem with a lot of the fine folks from the good 'ol US of A.
Never left the country, not willing to embrace other cultures, mind not open to other ideas, not willing to expand knowledge.

If you were referring to my remark [And don't look for me to visit anytime soon as I'm too busy here.], that was in reference to visiting that part of the World. I have been out of the U.S. MANY times. Most all of North America; a lot of South America; Japan, Korea, Australia, New Zealand, and parts of the South Pacific. Sorry if I didn't get to your part of the Planet.....yet. I won't bother to comment on the rest of your statements.

[CONF iture]

Yes, but please don't forget that Hamburg came very close!
PBL
As far as I know, HAM did not imply any protection ... which one did you see ?
What is the FCOM reference that could correlate with the protection you think about ?

[ECAM_Actions]

Well, when they start making cars FBW, I'll quit driving too !Better stop driving now then.

All my recent cars have had electronic throttles. They also have power steering, and without it I doubt I'd be able to turn the wheel unless I was already going quite fast (I don't fancy the idea of driving a 2.5 ton vehicle with failed power steering).

I'm sure older cars without power steering are rigged differently. Modern cars are heavy in comparison (I'm fairly sure it is more than just being used to power steering - I'm no lightweight).

Back on topic: FBW or no FBW - it took PILOTING SKILLS to put that A320 in the drink in almost one piece. FBW merely made moving the flight controls easier, protections or no protections. Would Direct Law have helped? I'm skeptical it would have made any difference at all.

Mech backup however... :E

Best regards,
ECAM Actions.

[bearfoil]

In the P-47 Thunderbolt Flight Manual is a chapter on Ditching. It is three sentences long.

Don't Stall.
Don't Ever Stall.
Don't Ever Ever Stall.

The nose will Pitch Pole, and disintegrate. No more Sully, no More Skiles, and probably most the rest. FBW not an issue, whatever. IMO. :ok:

[Safety Concerns]

at last we are getting somewhere. following on from bearfoils post lets just shorten the NTSB accident report quote from

The NTSB concludes that, despite being unable to complete the Engine Dual Failure checklist, the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.

to

the NTSB concludes that the captain started the APU, which improved the outcome of the ditching by ensuring the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.

um looks like a pattern starting to appear.

[ECAM_Actions]

QUESTION: Did they ever get to the bottom of the Alpha Prot range? If not, the argument about protections against the stall are mute.

Too much emphasis is put on FBW protections, plain and simple. I suppose having g and roll protections were useful too? Let's not forget Alpha Floor protection. :E

Without any thrust from the engines, all Alpha Prot would allow you to do is have the highest rate of sink you can get at the lowest speed possible. Who is for about 3000 ft/min rate of descent at 125 kts?

The argument is ridiculous.

ECAM Actions.

[Safety Concerns]

maybe there is an argument for a different approach to FBW training at least.

It is shocking how many posters claiming to be pilots do not understand FE protections.

[CONF iture]

Would Direct Law have helped? I'm skeptical it would have made any difference at all.
The only thing is that Sully would have had the proper tool to soften the touchdown and not having those mysterious additional features built into the system which attenuate pilot sidestick pitch inputs, preventing the airplane from reaching the maximum AOA.

Interesting enough that the NTSB was the first one to underline such characteristic when actually it should have been specified already 20 years ago by the BEA following the Habsheim crash.

[bubbers44]

Seems from the videos of his touchdown in the Hudson he did it perfectly. He could have done it equally well in any aircraft he was flying with his talent. Hopefully we all could do equally well. Automation is not designed to ditch an airplane but it seems in his case it didn't hurt the outcome of the event. Probably didn't help either. What worries me is when the new generation of pilots with computer skills take over. They won't have Sully's talent to just fly the airplane. What will they do if both engines quit? There is no button for that.

[Safety Concerns]

Before I say anymore I want to make it clear that I have the greatest respect for all of the crew involved in the Hudson river episode. It wasn't just flying skills that did industry proud on that day.

However one cannot ignore a few basic facts just because they don't fit conveniently in the nice little picture most of you have painted.

Seems from the videos of his touchdown in the Hudson he did it perfectly.

Well come on now you can't have it both ways. Perfect landing with control stick at full pitch up but with normal law limiting the input. NTSB stating that the outcome of the incident was improved because normal law was active.

That is quite clearly english for FBW played a positive role by assisting some superb flying under incredibly difficult circumstances.

The NTSB statement was completely unnecessary if the aircraft manual control inputs had remained within safe limits throughout the ditching. The reality is the system intervened to aid a perfect landing. In fact some have suggested that the FE protections allowed the crew to trade every available knot for a reduction in vertical speed.

That is not taking anything away from the pilot who undoubtedly was still the major factor in a successful outcome. The fact remains however, ego's aside, things may well have concluded differently. This seems to have been confirmed in NTSB tests carried out after the accident in the simulator where all 4 pilots crashed under similar circumstances.

So my point is you can't have one without the other. FBW is a fantastic tool and aids flight safety. It replaces ego with hard and fast software routines that will save your butt.

What it doesn't do is replace the pilot who still needs to be on top of his game.

[ssunny1230]

really an awesome forum.
======
Campervan Hire UK (http://www.motorhomesavings.com)

[Los Endos]

'ECAM_actions' and all others who are in denial about the merits of the protections afforded by Normal Law....Read Fly By Wire by William Langewiesche. You will find that during the flare over the water at max Alpha, the Stall / High Alpha protection did indeed play a small but significant part in saving the day.

[bubbers44]

Sully did not need alpha protection to make his Hudson landing. Only a pilot that would stall an aircraft before touchdown would need that. Don't most of us pilots approach a landing surface at 1.3 stall speed, flair to stop descent rate and roll it on with a perfect landing most of the time? We can do it power on or power off, on a runway or on the Hudson. Landing in the Hudson requires judgement on optimum flap setting and deck angle on touchdown with almost zero sink rate. You certainly don't want to be stalled or in a high pitch attitude when the tail hits the water first. Read Sully's book. He never said the Airbus automation helped him in any way and I am sure it didn't. Maybe it would help a mediocre pilot but not Sully. If alpha protection intervened on his Hudson landing the tail was probably already in the river so had no affect on the outcome. He would have never stalled into the Hudson. He was too professional.

[Mad (Flt) Scientist]

The NTSB statement was completely unnecessary if the aircraft manual control inputs had remained within safe limits throughout the ditching. The reality is the system intervened to aid a perfect landing. In fact some have suggested that the FE protections allowed the crew to trade every available knot for a reduction in vertical speed.

That first sentence isn't really true. The control laws are significantly different between Normal and Direct laws, and I would imagine that while Direct Law probably gives Level 2 handling qualities, Normal law is undoubtedly Level 1, and may even be a "1" on the Cooper-Harper scale.. So even if the envelope protection features were never active, it is still highly likely that by taking the action to start the APU and thus maintain the aircraft in Normal Law, the crew gave themselves the best handling aircraft available to them and thus made the task of achieving the ditching easier (note: easier, not easy). I suspect its the improved handling in Normal Law the NTSB is alluding to here.

[Safety Concerns]

I don't think so. The NTSB statement is quite specific and has no place in the accident report unless it was related to the accident. It doesn't mention handling it mentions STALL

the NTSB concludes that the captain started the APU, which improved the outcome of the ditching by ensuring the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.

[edmundronald]

Safety Concerns contributed:

Maybe there is an argument for a different approach to FBW training at least.

It is shocking how many posters claiming to be pilots do not understand FE protections.





Best comment I have seen in years of reading Pprune (me SLF!).

I've seen this in a lot of tech related stuff, the philosophical aspects -why things have been designed in way X, and what can be expected of such a design as a result - are often left out of the training because of time pressure.

However, one can usually find some documentation which explains the design and what to expect from it.

Edmund

[bearfoil]

So, FE protections. CFIT. Honk back and roll max right. The Computer will escape nibbling at Stall and Rollover. That Right?? I like that one. But who would ever need it?

[Locked door]

No one, but you try telling that to a certain section of this forum!!!

I refer you all again to this video, no one will ever need more than this, and the best bit is that you can't hurt the aircraft. As an aside though the memory items include rolling wings level to achieve max rate of climb unless you have a clear visual on the problem terrain. And also stow the speedbrakes (AA didn't a few years ago and lost a perfectly serviceable 757 to CFIT).

YouTube - Airbus A319 - Very Fast Crazy Take Off (http://www.youtube.com/watch?v=pDz6sEdrcfM)

LD

[hetfield]

They were lucky, don't do it! The EMER ELEC genie may drop out.

[Mad (Flt) Scientist]

I don't think so. The NTSB statement is quite specific and has no place in the accident report unless it was related to the accident. It doesn't mention handling it mentions STALL

Reading the report, it actually seems a bit ambivalent on the operation of the flight envelope protection. Section 2.7.2 states:
The airplane’s airspeed in the last 150 feet of the descent was low enough to activate the alpha-protection mode of the airplane’s fly-by-wire envelope protection features. The captain progressively pulled aft on the sidestick as the airplane descended below 100 feet, and he pulled the sidestick to its aft stop in the last 50 feet, indicating that he was attempting to raise the airplane nose to flare and soften the touchdown on the water. The A320 alpha-protection mode incorporates features that can attenuate pilot sidestick pitch inputs. Because of these features, the airplane could not reach the maximum AOA attainable in pitch normal law for the airplane weight and configuration; however, the airplane did provide maximum performance for the weight and configuration at that time.

The Airbus simulation indicated that the captain’s aft sidestick inputs in the last 50 feet of the flight were attenuated, limiting the ANU response of the airplane even though about 3.5° of margin existed between the airplane’s AOA at touchdown (between 13° and 14°) and the maximum AOA for this airplane weight and configuration (17.5°). Airbus’ training curricula does not contain information on the effects of alpha-protection mode features that might affect the airplane’s response to pilot sidestick pitch inputs. The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane.

The NTSB concludes that training pilots that sidestick inputs may be attenuated when the airplane is in the alpha-protection mode would provide them with a better understanding of how entering the alpha-protection mode may affect the pitch response of the airplane. The NTSB recommends that the FAA require Airbus operators to expand the AOA-protection envelope limitations ground-school training to inform pilots about alpha-protection mode features while in normal law that can affect the pitch response of the airplane.

So while the alpha protection did prevent a stall, it also reduced the ability to flare. Overall it turned out ok, but there's a suggestion that might not always be the case.

[Safety Concerns]

its hard to see how stalling could have helped here. The system helped sully by keeping the aircraft at max performance for the configuration.

[goldfish85]

Safetyconcerns wrote

It is shocking how many posters claiming to be pilots do not understand FE protections.

I think that's true for pilots who have not been trained on envelope protection. I know I was until my training. I also think Airbus did not go a very good job of training in the first few years of A-320 (Habsheim, Bangalore). I had a one-hour sim exposure to the A-320 in the mid '90s. The sim instructor over-emphasized using the protections. At one point he had me select landing configuration at about 300 knots, pointing out that I no longer had to worry about limit airspeeds -- the airplane would lower the gear and flaps when the speed was right.

In the mid 2000's, I went through Airbus training at MIA. The first sim session was flown in Direct Law -- See it's an airplane. I think they realized they had made the wrong impression in the early 90's.

Envelope protection had saved many airplanes. An FAA review of upsets shows this clearly. (Lambregts, AIAA Paper 2008-6897)

Goldfish

[ECAM_Actions]

'ECAM_actions' and all others who are in denial about the merits of the protections afforded by Normal Law....Read Fly By Wire by William Langewiesche. You will find that during the flare over the water at max Alpha, the Stall / High Alpha protection did indeed play a small but significant part in saving the day.bubbers44 said it nicely.

I think you also failed to understand my point that so long as you don't get close the edges of the "envelope" defined by Normal Law, whether Normal or Direct Law is active is moot.

Alpha prot only helps if you're near the stall, bank angle prot only works when you're trying to roll more than 67 degrees, and g load demand only prevents a pull-up exceeding 2.5 g.

I doubt very much that Sully attempted any of those things, so it rendered the protections utterly useless.

I'm more interested in why the tests in the sim failed to have a good outcome. Hasn't this been found to be the case before, that what happened in reality couldn't be replicated in the sim?

ECAM Actions.

[Safety Concerns]

Alpha prot only helps if you're near the stall,

got it in one.

[Locked door]

Exactly the point of protections, they are there in the background but should never, ever activate.

To ditch an a/c you want to be as slow as possible with the minimum v/s possible. The advantage of FBW is that if you misjudge it or there's a wind shift, you won't drop a wing and cartwheel, all that will happen is your v/s will increase to the new minimum possible.

I don't know the ins and outs of the Hudson incident, but the best possible outcome was achieved regardless.

LD

[CONF iture]

Goldfish
AIAA-2008-6867
Airplane Upsets: Old Problem, New Issues
Is it the document you refer to ?
Would you have a link to the full paper ?

It is shocking how many posters claiming to be pilots do not understand FE protections.
Safety Concerns
I do not know if you claim to be pilot, but reading your discourse I can tell you do not understand FE protection ...
Just curious here : Have you ever flared an aircraft ?

This seems to have been confirmed in NTSB tests carried out after the accident in the simulator where all 4 pilots crashed under similar circumstances.
Totally erroneous, please start reading the full NTSB report first and especially page 49-50 for the simulations ...

[Clandestino]

Which limitation did they try to bend on QF72, please remind me Clandestino.

So what happened there? There they were, cruising serenely at FL370, when all at sudden, malfunctioning protection activated and sent them to their whopping 680ft plunge, following by another enormous 400 ft dive. "Yes they were lucky this time, what would have happened if they were on short final", I can hear you scream. Well, they were unlucky to have it happened at the first place. There are no records of it happening before or after, anywhere in the world, on any FBW Airbus AFAIK. We stil don't know what triggered the alpha prot, one of contributing factor to our continuing ignorance certainly being extreme rarity of such an events. DP Davies has treated the subject of statistically acceptable risk of protections activating when not required in chapter discussing the stickpushers. If you have third edition, it's page 131. Nothing new under the sun.


Why don't you question SC ... He wrote that 'the protections are there in the first place because you lot kept crashing'
Can you produce figures that would support such statement ?

My apologies, I got the wrong impression you were talking about FBW Airbi hull losses, while you were referring to the loss of control accidents of non-protected aeroplanes. Aviation safety network is good starting point for research, yet again as accidents are very rare compared to number of operations, it's better to concentrate on case studies instead of statistics. Functioning protections prevent from spiral dive, stall, overspeed and overstress. It is empirically proven that one can remain within protection boundaries and turn FBW Airbus into scrap metal.

If the XL Airbus in Perpignan don't follow the pilot request in the final dive, that's because of the G load protection to make sure that the aircraft is intact up to the crash site.

Nope. It didn't follow it because THS remained at full nose-up position throughout the event. Elevator would be unable to overpower it even if the puzzled computers had operated it in demanded sense. Again, it has everything to do with DP Davies and nothing with Ziegler's concierge.

If i'm on my 'dinosaur' aircraft flying at 330kts and want to pull up to 60 deg up and wash the speed off, i can, because i.m in control.

All well if your dinosaur is F-4. In the enlightened age of FDM, this would be career ending event if performed while flying transport category aircraft.


Rocking chair in front of breakfast TV.
Anyways pilot or not we will all obtain this rating

That's an extremely optimistic view. I used to know a decent bunch of pilots who were never able to put it on their licences despite their best efforts.

I don't think there's a single incident where the protections have caused a hull loss - at least not when there hasn't been a major malfunction.
Yes, but please don't forget that Hamburg came very close!

I disagree. Hamburg was not protection issue, one of the contributing factors was halving the control travel while transitioning from normal to ground law. However, wrong stick input was used during decrab in winds that exceeded demonstrated crosswind component by the test pilots, aeroplane was landed on the downwind wheel and they got away with scraped wingtip fence. That's good enough control authority in my book.

There were two accidents that involved SA Airbi making heavy landings during turbulence that triggered alpha prot - St. Johns in 1999 and Bilbao in 2001. After Bilbao, alpha prot got relaxed by desensitizing it to high AoA rate of change. Of course, we don't really know whether the outcome would be better or worse in either of the cases if the protections didn't intervene.


To ditch an a/c you want to be as slow as possible with the minimum v/s possible.

Perhaps on some aircraft, not on A320. Desirable method is going for 11° pitch with RoD as little as possible. If you can't make the RoD, you don't sacrifice the pitch to get it. Capt Sullenberger did hell of a job out there, there's no point in second guessing what he actually ment to do or how could he done it better. I can only hope that I'll be as good as him if my time comes.

[bubbers44]

I think Sully knew airspeed and attitude was the only thing that was going to matter in his splashdown. He was too good a pilot to depend on automation to help him so he obviously used his flying skills to make sure he had the right speed to flare and zero out his sink rate before ditching. People who love Airbus and think that saved the day are totally wrong. Sully saved the day by being a good pilot. He saved the day, it didn't matter what he was flying.

[DozyWannabe]

People who love Airbus and think that saved the day are totally wrong.

I'm pretty sure no-one on this thread has suggested that. The most that has been said is that the protections may have provided a valuable backstop if things became more difficult prior to touchdown, which they didn't.

[CONF iture]

The NTSB statement was completely unnecessary if the aircraft manual control inputs had remained within safe limits throughout the ditching. The reality is the system intervened to aid a perfect landing. In fact some have suggested that the FE protections allowed the crew to trade every available knot for a reduction in vertical speed.

And who are those "some" that don't understand either what a flare is all about ?
Direct me to the data in the report that support such statement ...

... and zero out his sink rate before ditching.
That's right, Sully tried its best in that perspective, but the flight control computers as they are programmed decided they knew better and didn't have to follow the pilot's request ...

What amazes me is that among all the simulations that have been performed afterward in Toulouse, no one thought to put the aircraft in beautiful DIRECT LAW to get rid of all those supposedly marvelous and magical features and/or protections, and see how a guy with some experience can actually nicely flare that aircraft ... !?

Is it that no one thought about it ... or is it that no one did really want to embarrass Airbus ... ?

[Safety Concerns]

A few salient points

The NTSB concludes that the captain’s difficulty maintaining his intended airspeed during the final approach resulted in high AOAs, which contributed to the difficulties in flaring the airplane,

When the airspeed is high enough, such as the airspeed recommended in the QRH, the AOA never reaches the flight envelope protection activation threshold.

The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane.

The captain’s difficulty maintaining his intended airspeed during the final approach resulted in high angles-of-attack, which contributed to the difficulties in flaring the airplane, the high descent rate at touchdown, and the fuselage damage.

The professionalism of the flight crewmembers and their excellent crew resource management during the accident sequence contributed to their ability to maintain control of the airplane, configure it to the extent possible under the circumstances, and fly an approach that increased the survivability of the impact.

the NTSB concludes that the captain started the APU, which improved the outcome of the ditching by ensuring the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.

[bubbers44]

Capt. Sully - Why Ditched the Flight 1549 in the Hudson River? (http://hubpages.com/hub/capt-sully)

An interview with Sully.

[lotusexige]

In the P-47 Thunderbolt Flight Manual is a chapter on Ditching. It is three sentences long.

Don't Stall.
Don't Ever Stall.
Don't Ever Ever Stall.

The nose will Pitch Pole, and disintegrate. No more Sully, no More Skiles, and probably most the rest. FBW not an issue, whatever. IMO. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

In his book 'Make Better Landings' Alan Bramson refers to the myth of the full stall landing. He said 'What happens when a well behaved aircraft stalls? The nose drops. What happens when a not so well behaved aircraft stalls? The nose and a wing drop.'
I might not be quoting exactly as its aboy 25 years since I read it but you get the drift.

[bubbers44]

P47 Don't ever ever stall. That works equally well in any airliner including an A320. Sully knew that so wouldn't have stalled prior to splashdown. If the Airbus computer didn't give him the last 3 degrees of AOA in the flare before stall it still worked so everybody got out alive. The next A320 crew might add 20 knots to the approach speed to counteract the computer to get a zero descent touchdown. You still touch down at the minimum speed since you have a long river and can flare as long as you want. I loved his video. He was totally in control. He knew he had to have the wings perfectly level on touchdown. I loved his book.

[PBL]

How has a thread on safety warnings following an A321 incident morphed into yet another interminable discussion on the Hudson River landing?

PBL

[jcjeant]

Hi,

Some update from Airbus .... interesting
Google Vertaling (http://translate.google.be/translate?u=http%3A%2F%2Fwww.lesechos.fr%2Fentreprises-secteurs%2Fair-defense%2Factu%2F0201018360638-airbus-bulletin-d-alerte-sur-les-sondes-pitot-de-l-a330.htm&sl=fr&tl=en&hl=&ie=UTF-8)

Original link:
Airbus*: bulletin d'alerte sur les sondes Pitot de l'A330 - CONSTRUCTION AERONAUTIQUE AIRBUS (http://www.lesechos.fr/entreprises-secteurs/air-defense/actu/0201018360638-airbus-bulletin-d-alerte-sur-les-sondes-pitot-de-l-a330.htm)
But what this will change ?
What will be the result ?

[bubbers44]

In the B727 days everything was simple. You looked at your FE panel and cockpit display and things were crystal clear what had to be done. Now with the automated everything it is much more difficult to resolve failures vs the 1980's. Is this progress? Too much information when you only want to deal with the main problem can be a hinderance to a safe solution. KISS comes to mind. Keeping things simple always seems to work best. Always worked for me. Does it work for anybody else? Remember, I don't have a college degree.

[DC-ATE]

bubbers44 -
In the B727 days everything was simple. You looked at your FE panel and cockpit display and things were crystal clear what had to be done. Now with the automated everything it is much more difficult to resolve failures vs the 1980's. Is this progress? Too much information when you only want to deal with the main problem can be a hinderance to a safe solution. KISS comes to mind. Keeping things simple always seems to work best. Always worked for me. Does it work for anybody else? Remember, I don't have a college degree.

Hey.....I got someone who agrees with me !! I'm with you there, bubbers44 !! Only replace that B-727 with a DC-8 !!

[bubbers44]

I got my FE written on the DC8. I know all about turbo compressors etc. Aren't those derelects great? Now that I am retired I never care about what law I am in. Isn't it great? I kind of lied because Boeing doesn't have laws. Only Airbus. I remember looking over my right shoulder on takeoff on the 727 seeing the #1 gen kick off before V1 on a slick runway in the carribean at max weight. I told the FO flying it was OK, the FE would fix it. Unfortunately at V1 the FE selected #1 for essential power and we lost our instruments. I said he will fix it just fly. He finally got us back but I always knew what was wrong and how to fix it but with the new technology it might not be that easy.

[White Knight]

the FE would fix it. Unfortunately at V1 the FE selected #1 for essential power and we lost our instruments. I said he will fix it just fly. He finally got us back but I always knew what was wrong and how to fix it but with the new technology it might not be that easy.

Well - the old technology was obviously so easy to fix the the FE did a cracking job first time round:rolleyes::rolleyes::rolleyes:

Actually - the new technology is fine and easily understandable! It just requires a little more effort than the useless CBT course during a transition which is A) basic and B) caters for the stupid....

Personally - any type I fly I like to know the systems inside out! And it's entirely possible with the Airbii:ok:

[bubbers44]

The FE should have shut a pack off to reduce the electrical load and not touched essential power since it was powered by #3 gen. He just came back from flying FO on another airplane and was being given a route check by an FE check airman so knew between the two of them they would figure it out. It was kind of like driving a 56 Ford vs a 2010 Lexus and the engine quits. I could fix the Ford.

[White Knight]

It was kind of like driving a 56 Ford vs a 2010 Lexus and the engine quits. I could fix the Ford

'Cept when the Ford or Lexus quit you are on 'terra firma':hmm: Bit of a difference I would say:ok: I do see your point with regard to pure engineering though - however, the important thing is the knowledge as to how to deal with whatever failure you have and I feel that the modern CBT is rubbish compared to a 'chalk and talk' transition!!!! I'm sure most would agree with this too!