Correct, however I am thinking that if there was some sort of catastrophic electrical failure (ie. BAD lightning strike) then the RAT wouldn't have had anything to power (ie. computers suffered current spike and died along with any other electrical system).

Voltage melts nothing. It's CURRENT that does it. Please stick to science. Of course you have to have a voltage to make a current flow but it's not that simple. You can be sure there's PLENTY of voltage in ANY lightning strike. The released charge results in the current that does the damage. The bigger the cloud, the larger the charge and hence current.

That why a human can touch a Van der Graaf generator at say 2 MV and just get a 'shock', the charge / current is too low to do any damage.

Voltage is NOT the problem.

Graham

The RAT would only be useful if the infrastructure it feeds electrically - essential/emergency buses - is not compromised.

Good Post by PJ2
 

PJ2, and excellent post from someone who obviously knows their stuff. We used the x100 rule in the Mirage III O to work out other fighter's relative altitudes, and I often use the "short of the ground-line" technique to spot buildups ahead. Put the near edge of the groundline at 80-ish miles and wait for the nasties to appear just inside that. Over the water, it's easier.

Capn Bloggs;
Yup. That brings to memory the DC8's, and later the 727's analogue radar - that technique worked like a charm. I also recall the small "band" of slightly different signal on the screen that seemed to indicate the drift-angle of the aircraft...not sure that's what it was, but it seemed to work!

PJ2

Concur with the above. In VMC, the mark 1 eye ball is as good as anything else.

As far as trying to out climb WX, it is as bad to try and out climb wx as to fly through. We are talking G protection, here.. Better to consider descending a few thousand feet than climbing, if you know the going is going to be tough.

I have watched in amazement at some experienced Captains, considering to climb above wx. A possible fatal error, when G protection is sacrificed.

The aircraft will and is designed to take "one hell of a hammering". The trouble comes when you stall out.

joehunt;

Re descending, yeah, all else being equal - depends on what the SAT is doing as you know, but climbing over - nope- concur for all the reasons given.

This brings up the issue of obtaining clearance from the oceanic controller and the FANS-1 item someone raised earlier, (ADS-B and CPDLC)...I don't think the area he was in is ADS-equipped yet, is it? If so, that telemetry would be of use, of course and I would expect that data to be captured now. I recall using both ADS and CPDLC on the Pacific as early as 2005 (or '6) and it worked for beautifully for weather diversions and altitude changes...quick, and painless unlike the HF.

PaleBlueDot,

The satellite position reporting system you describe already exists in many inexpensive forms, and has been made mandatory by many agencies in Canada for aircraft deployed on firefighting missions, etc. Unit includes an internal GPS, with a small antenna that (in helicopters at least) can often be mounted on the dash, and sends position reports at a user determined frequency (e.g. 30 sec, 2 min, etc). There are many different companies making these units, here's a few...

http://http://www.latitudetech.com/
http://http://www.blueskynetwork.com/
http://http://www.skyconnect.aero/

Obviously it would be a much bigger undertaking to mount these on a fleet of airliners than it would a helicopter, which is where I've seen them used, but its unfortunate a tool like this does not appear to have been on this flight.

At about the time in question, there was in the DIKEB area (see map above) a SE-NW oriented pack of clouds, which in the moonlight from the low 7 o'clock position I would not identify as CB or squall line, more like a thick fog/haze area, but which showed up on wx radar as a thick (ylo/red) and continuous line about 20 NM thick and possibly extending to the TASIL area. At 370 or 380 we diverted 30 NM west of the airway, a bit shaky but not too bad. No lighting activity noted.

It was indeed difficult to switch from Atlantico to Dakar HF, in fact we had no contact until about 1:30 into their airspace.

Condolances to the crew and passenger's family.

In view of the difficulty mentioned in clearly identifying thunderstorms with radar at night, shouldn't it now be standard to issue each aircraft or crew with a set of nightvision goggles or some such device to help visually identifiy where the activity is?

Generator failure and possible consequences
 

On a recent MY A330 flight we boarded with broken APU and shortly after TO lights and other cabin electrics failed. We were advised that the the "generator had tripped". They reset generator and shortly afterwards all lights went out again. Notwithstanding more than half a dozen resets, we spent the remaining 3 plus hours until touchdown in darkness. We were told that there was a serious problem with the generator.

Apart from a number of questions this may raise, I was reliably informed by A330 driver that no more than ONE reset is recommended due to vulnerability of wiring in A330.

Ironically, the aircraft in question, which like most modern jet airliners was fitted with ADS-B, would have been squittering its position, altitude, groundspeed and ROC/ROD at half-second intervals continuously during the flight on 1090MHz...

Captain Richard Moody of British Airways...
 

Former BA captain Eric Moody said a twin-engine accident was inevitable
(quote from the sky.com news website)

Someone needs to have serious words with this "airline professional" as the facts of this accident are still unknown, but EVERYTHING at the moment indicates an electrical short circuit, hence if this "captain" has any knowledge of Airbus, he would know this same scenario could happen to the A340 and A380 both 4 engined aircraft! Please "captain" Moody refrain from any suggestive comments about 2 engined aircraft until all the facts are known. This is very unprofessional behaviour suggests now that twin engine ETOPS operations are responsible for this accident, whilst it could still have NOTHING TO DO with twin engine operations. :mad:
We could instead also argue the safety of commercial fly-by-wire aircraft! Unlike our military counterparts, we don't have the option of escape when things go horribly wrong..........


When the 330 suffers complete electrical failure from the generators, a ram air turbine would deploy and provide electrics in an electrical emergency configuration wich powers mainly essential instruments on the captains side and other essential electrical equipment, like computers.

Furthermore if the ram generator also would be unavailable flight on batteries only would be possible, since I'm not an 330 pilot. I don't know how long these would have to last for.

As a fly-by-wire aircraft (A320/330/340/380), the 330 relies on it's computers to control the flight control surfaces... with a complete electrical failure, there is a last resort: mechanical backup, wich gives the pilot control of the rudder and the horizontal stabilizer. This is designed to make it possible for the pilots to fly straight and level, TO RECOVER THE FAILED COMPUTERS. Mechanical backup is not designed to fly and navigate the aircraft. Whilst possible, it is hard to do even in still air.

The scenario mentioned, suggests the 330 ended up in heavy turbulence and the reports also suggest a lightning strike, that caused short circuit of electrical systems. This Indicates that flight AF447 ended up in a CB. In the possible scenario of the aircraft ending up with no electrics, flying on mechanical backup, in the severe turbulence of a CB the poor pilots wouldn't have had a fighting chance to regain control over the aircraft...

A scenario I've always mentioned (always waived off by trainers and experienced Airbus pilots and of course statistics as a very very unlikely event) and I as an Airbus pilot have been scared of ever since I've transferred from Boeing aircraft...

My deepest sympathy goes out the the crew, passengers and friends and relatives. Let's hope that the flight crew did manage to regain control of the aircraft and managed to ditch safely somewhere on the atlantic.

:sad:

These are two ACARS messages from F-GZCP on the night it disappeared:

ACARS mode: 2 Aircraft reg: F-GZCP [Airbus A332]
Message label: _ Block id: 0 Msg no: S72A
Flight id: AF0447 [GIG-CDG] [Air France]
----------------------------------------------------------[ 01/06/2009 00:53 ]-

ACARS mode: R Aircraft reg: F-GZCP [Airbus A332]
Message label: 2F Block id: 0 Msg no: M14A
Flight id: AF0444 [CDG-GIG] [Air France]
Message content:-
#0936/+47.31-001.30
----------------------------------------------------------[ 31/05/2009 11:36 ]-

(www.acarsd.org) With ACARS messages being listened to routinely by enthusiasts, I'd be surprised the later 4 minute exchange would not have been picked up somewhere.

Am I correct in thinking that the ACARS system also allows for pilot input into the messages? Thus the crew could have been communicating through ACARS if all other radio communication was not received.

A message from the same a/c on May 11 for example reads: MAINTENA BJR.EN CABINE TOILET L54 FUITE DESSOUS LAVABO NIVEAU EVAC.+SIEGE 4K INOP ELEC.MERCI CDB CAMUS

DaveReidUK;
Yes, concur, but only in FANS-1 areas. I am starting to come to the conclusion that the area in question is not FANS-equipped, (see comments re HF by Flapsnegative just a few back).

That is not an area in which oil wells are found. Thus, re "flames seen by TAM", there is a very outside possibility that such may have been picked up by satellite, although obscuration by cloud could be an issue.

PJ2, weather radar
 

Extensive post PJ2, but for the completeness I would like to add "use of gain" and "black spots".

Gain: like other modern radars (post 1980's), the A330 radar is a low energy (weak) radar. Gain is the intensity of the radaroutput and is preset in auto-mode but that doesn't give a clear picture so often you use it in max gain; that pinpoints the cells more clearly.

Black spots: The radarsignals are reflected by the heavy precipitation in the cells, back to the radar so they never reach the area behind the cells. That means that you'll never exactly know what is behind the first storm untill you passed it.
Often these storm systems are lined up (like a squall line) so once you've passed the cells you are in the clear again, but these tropical storms in the ITF are so extensive that after avoiding the first couple of cells, more will turn up on your radar.

Indeed the radar is not made for weather penetration, but that applie to the cells only. Sometimes you really have to penetrate a weather system and use your radar to avoid the cells.

Darkrampage:
Quote:
pilotara
if there is an electrical failure or problem if i am not mistaken the RAT would deploy. RAT would power some crusial sustems in order for the pilot to have some sort of reference. I am not an airbus expert but just thinking out loud.
Correct, however I am thinking that if there was some sort of catastrophic electrical failure (ie. BAD lightning strike) then the RAT wouldn't have had anything to power (ie. computers suffered current spike and died along with any other electrical system).
-----------------------------------------------------------------------

All electrical equipment, (computers, ect) are subject to indirect lightening tests, so the chance of all equipment failure is minimum.
The tests are done in a lab by trained independant staff, and an independant witness to oversee the tests and verify the results (have done this myself)

Flapsnegative - you appear to have been in the area at the time? Was there any chat on 123 about the ride there?

Do you know if the (reported) ?TAM? a/c report of 'fire sighted' was reported on 121, HF or 123?

Have there been any statements yet from AF about MEL items on the a/c?

Apologies to all if I have missed these queries, but the thread is already going the 'way of all'.

golfyankeesierra;

Thanks for adding some thoughts; concur on "gain" and lines in the ITCZ - mentioned "black spots" but not well so thanks for making the point clearer.

I think it's crucial for non-aircrews who are genuinely interested to know a bit about how this work is done so that more intelligent and helpful questions can be put. Perhaps the thread may return to an enquiring stance which values curiosity over the ego being expressed in individual pet theories and ill-considered speculations at this stage of affairs about what happened.

BOAC
"Have there been any statements yet from AF about MEL items on the a/c" - excellent question - was wondering too.

The way of all threads......yup, (heavy sigh) but the mod's doing great work, I see...

@ Willoz269 No cause against FR in Intl politics? France, like 46 other countries are in Afghanistan. It has 3000 troops there, Australia has 1500 and that was enough to justify the Bali bombing so what makes France immune? Algeria and a long history is another example of Intl politics...

The fact is however that I agree with you, this is almost def not a terrorist bombing, not least for the apparent failure of anyone (credible) to try and take credit for it.

However, its not just terrorists that plant bombs, criminals, drug lords, insurance fraudsters, governments have all – historically – brought down passenger planes to kill one or all people on a flight for various reasons. Bombs are the number 1 way to bring down an aircraft and the best place to do that is over the ocean to prevent follow up investigations.

That practically AF’s first words on the subject were “its not a terrorist attack” or words to that effect is the standard airline industry opening line because nobody in the industry wants people to stop flying. That the news media can only think in terms of bombs=terrorists=denial=weather=lightning strike is a bit of a pity, and why I came to PPRUNE and not BBCnews.co.uk. But just because the media isn’t thinking about it doesn’t mean that the authorities aren’t on the case - just as they are scanning the passenger list for potential bombers they'll also be scanning the list for potential targets - judges, politicians, criminal kingpins, celebrities, gingers etc..

My thoughts are with all concerned and I hope a quick investigation. If my (unlikely but not impossible bomb) theory turns out to be correct I am sure the French DGSE will be on the case and I cannot think of anyone else possibly apart from Mossad I would rather have hunting the globe for a bit of revenge.

Once coming back from Salvador we encountered a line squall in approximately the same area. As we got closer i.e. about 80 - 160 nm we could see a dark spot on the radar i.e. a clear area of sky and that is where we went. However all hell broke loose as we entered what must have been a dying cell fortunately we where only in it long enough for me to get the engine and airframe ant-icing and ignition on before coming out the other side.

There was a BA behind us who I warned but was to late as they had also entered it as did TAP behind them. We spoke to them afterwards and they also had no returns on their radar

We were lucky in that it was very short lived and that the cell was in its decaying stages. As you can imagine there was a long discussion about what had happened between the three of us that where on the flight deck that night. The conclusion was that there was nothing we could have done to avoid it as there were no returns on radar and it was pitch black night so no chance of a visual sighting.

With regards to use of radar when I am CM1 I generally keep my radar on 80 with .5 down tilt with CM2 on the next range up. If I start getting returns I go down a scale when the returns are half way down my screen. With the CM2 also coming down that way i get the strongest returns for avoidance whilst using the CM2 to pick a route around what might be behind.

Clearly you have absolutely no idea who this guy is.

You are referring to (probably) the only airline pilot in history to have flown a 747 in glider mode. He is as entitled as anyone I can think of to express his opinion on how many engines it's good to have available to relight, whether or not engine failure is implicated in this accident.

DaveReid

I think you have missed the point.

We can all have plenty of respect for what Capt Moody acheived that day, but it is far too early for him to blame this event on anything to do with ETOPS - how can anyone even hint that that was a factor without more evidence?

Ex Maintenance anything left behind or a dimmer low setting?
 

Some of you may be missing the point about the ETOPS factor. It's not so much the 2 v 4, but the fact that ETOPS constraints may have contributed in the flight having to flight plan and take a less than optimum routing in relation to the severe weather in the area. A four holer may have had more routing options available.

Back on page 5, I pondered whether there was any history of rollback on CF6s. I could vaguely remember a safety notice when I was a user of CF6s, and I've found it in the FAA SAIBs.

This Special Airworthiness Information
Bulletin (SAIB) advises you, owners and
operators of all aircraft equipped with
General Electric Aircraft Engines (GE)
CF6-80C2 and CF6-80E1 series turbofan
engines of reports of on-going engine
flameout events during flight and two recent
incidents involving dual engine flameouts on
twin engine airplanes. These engines are
installed on Boeing B747, B767, and MD11
series airplanes and Airbus A300 and A330
series airplanes.

Background
Since the early 1990’s, there have been 32
reported flameout events on airplanes with
CF6-80C2 and CF6-80E1 series turbofan
engines. Two of these events involved total
power loss with a subsequent in-flight relight.
(Source : NE-07-01 October 12, 2006 Special Airworthiness Information Bulletins (SAIB))

Rollback occurs due to super-cooled water droplets in the vicinity of cu-nimbs. Just to throw a hypothesis in the pot, - ...Double engine failure, electrical load shedding and steady depressurisation (no more engine bleed air) = automatic ACARS message. Controlled descent on standby instruments, but an almost impossible ditching in the dark, with a break up on touchdown.

Your "informed sources" are not very well informed.

It would be interesting to learn the content of the stream of maintenance messages. Were the failing systems in close proximity to each other? The space shuttle that disintegrated on re-entry registered a series of proximate failures before the catastrophic break up. Could the maintenance messages be indicative of a spreading fire in the avionics taking down systems one by one?

Certainly not an issue in this accident, but the comments about crews leaving radar switches in the dim position brings me to ask: how many of you fly along at night or in IMC (as I've seen many FOs doing) with 'TERRAIN' selected rather than radar?

It seems this is being taught by some trainers. Call me old fashioned, but I really don't like the practice.

A332 at Bangalore
 

@Stall Pusher:
Ok, now with a 'decent' internet access I found the info I was looking for.

F-GZCB <- grounded at Bangalore for some days with elec. problems
F-GZCP <- AF447

./J

I'm sorry but your all just as bad as each other and no better than Capt. Moody. It is all pure speculation as to the cause -even if it be informed speculation. There is unlikley to be a single cause for the loss of this aircraft and those on board. It does look as if weather may have been one factor and that there is evidence of loss of lx shortly thereafter. More than that is guesswork.

A ditching at night would be difficult for any crew, however experienced even when the sea state is calm. No wreckage has yet been located which doesn't mean anything except that a debris trail would be expected if the A/C broke up. If a dicthing was successful or then one would expect that EPRIB would have been activated or that there would be evidence of the ditching, rafts Lifejackets etc. seatcusions, plastic panels etc. which would by now have been located. There have now been reports of burning wreckage close to the expected track of the Aircraft - although this was from the commander of an aircraft inbound to Brasil who at the time was unaware of the accident - Sadly, the situation doesn't look good.

If all the electrics fail and the computers get knocked out, the airbus has a last resort: mechanical back up. It's only desinged to make it possible for the crew to remain straight and level flight, to recover any lost computers. Navigating and flying the aircraft to a safe landing in mechanical back up is probably as difficult as trying to land an aircraft with no flight controls on only it's engines.....

Mechanical back up, would indeed not give pilots sufficient control in extreme weather and turbulence conditions. Try to fly straight and level in these conditions with full control authority!

As this scenerio has always been waived off as "impossible" it is starting to look like it has indeed now happened... plenty to think about there in Toulouse

RE: Terrorism - Surely if it were the case an organisation would take responsibility? Otherwise, wouldn't its purpose be defeated?

On radars - Someone mentioned it earlier, but blackspots can produce some pretty heinous conditions. I'm not sure about the 330s radar, but on some of the older 744s i've seen wx literally 'pop' onto the screen within 20nm, being hidden previously by other walls of wx. In areas of exteme activity, i.e. frontal lines, tropical depressios, this could be potentially dangerous, with nowhere to turn...

I hope the investigators can ascertain the cause.

Surely, not through known severe weather! When I recently flew ATL-TPA we were informed by the F/D prior to departure that we would take a weather avoidance route which would (and did) add about 10 mins to the normal flight time. This on what is generally a short 1 hour flight!

If I remember correctly,a few months back the crew of a Qantas 744 was forced to rely on weather reports from an Air New Zealand 772 when its own radar broke down and a Qantas A333 on its way to Shanghai from Sydney was force to turned back after a weather radar malfunction on board. So I guess there are legal requirement.

I said CLOSE to most cost effective routings, no implications of taking it through severe weather... and even if operations planned it, the authority lies with the captain/crew to accept the routing or not!

ACARS messages regularly contain text input by flight crew, not just automated messages. Could the crew have tried to communicate via ACARS, if all other radio transmissions were out or not received?

Would that account for the 4-minute ACARS exchange AF is talking about?

Did the pilot of the TAM aircraft who saw several orange points on the ocean while flying over the region comment on the weather conditions at the time???

Sorry if this has been mentioned already- the posts keep changing & disappearing as I read-

I was under the impression that modern aircraft have ELTs which activate on contact with water or at a certain level of deceleration. So far I've heard no mention of any signal/pingers.

In the case of an in-flight breakup, would the ELT not activate then? Does it need either a) water or b)high deceleration g's (or whatever the technical term is) to activate?

From a cabin standpoint we have our portable 406 but I wasn't sure how the fixed one works. Cheers if anyone can clear that up.

The storms associated with the ITCZ are extremely active, with tops often over FL500 and massive vertical movement. There is often a 'black hole' caused by shielding which looks like a safe route but then closes up once you have become committed. The only option is to avoid the area with whatever deviation is required.

If the aircraft did break up due to severe turbulence then the first item to fail would probably be the engine pylons. This would tie up with the electrical and pressurization failure messages sent via the datalink.

Dave

A couple of questions for all the Airbus people on here?

Could the ACARS reported 'SHORT CIRCUIT' be a pre-cursor for the aircraft dropping into the 'ELEC EMERG CONFIG', resulting in the red ECAM message 'LAND ASAP'?

In the 'ELEC EMERG CONFIG' do you still lose AutoPilot, AutoThrust & Flight Director? Is the ALTN LAW at this stage or only after the PNF selects 'LAND RECOVERY?

With the Airbus's having Kapton (please forgive my spelling if spelt wrong) wiring, could the turbulence be sufficiently intense to cause the 'chafe'ing & 'arc'ing that we saw in the SwissAir MD-11 disaster?

I only flew the A330/340's for 3 years & that was quite some time ago, but please PM me if you don't feel you can post your thoughts on open forum.