AAIB initial report out on BA B777 crash at LHR

[barrymung]

In summary: while we need to consider every possibility with extreme skepticism, when something like this happens, by definition it is an extremely rare event. Therefore, while the argument "that would be extremely rare" provides a necessary skeptical perspective, it doesn't invalidate the claim (and, for those playing on conspiracy-theory "logic", actually validates it).

However, it is important to remember that *something* happened.

If we take the view that EVERY possibility is virtually impossible, then the only factor left would be pilot error!

From the accounts so far it appears as though the most likely reason for the problem was either engines, electronics or fuel.

[Contacttower]

After all, what is there to hide?

There's the possibility of 'tainting' witnesses of the crash, which could influence the investigation.

[HarryMann]

Fuel waxing or icing may be unlikely, but from Riverman's post, FADEC port or sensor icing may not be so unlikely...

Why wouldn't this AD cover Trent installations as well... ?

Simply, there hadn't been any (or not 7) instances of LOTC reported on Trents...

What is the ratio of RR 777's to GE 77's operating please?

[ManaAdaSystem]

Speaking in general, the only time I have seen a fuel temp of -42 degrees celsius was above Mongolia enroute to Bejing. OAT at that time, -72 degrees. We managed to stabilize the temp by increasing the cruise Mach. TOD came not so long after.

We would be subjected to those same temperatures on the way back, but normally we would be at a lower level and slightly higher OAT. The air would also get warmer as we progressed towards Europe. I have never seen an OAT of -71 degrees over Europe and UK. Until now.

As for Morphemes:

"Well sorry if I sound dismissive (which I am) but even several hours in very low temps won't send 30-odd tons of fuel below -47degC.

As well the obvious question - why didn't all the Far East-originating westbound traffic fall out of the sky together?"

A: You are wrong, and B: We take the neccessary steps to keep the fuel temp in check. It's part of the job and covered in the manuals.

I don't fly 777's so I cannot comment on how these aircraft cope with low OAT's, but I know one warning system on that BA 777 did not work (low thrust warning) and it's not impossible other warning systems were "out" too.

No, I don't think waxing was the cause, but it cannot be ruled out as a possible.

The same goes for ice ingestion. There was an Ice warning out for moderate icing around FL 90 (reported over BNN if I'm not mistaken). 9-10 degrees on ground. Possible, but not likely.

IMHO, Gentlemen!

BTW, that the engines failed to produce thrust doesn't neccessary mean they were turning at idle (or something like it).

And retracting flaps when you are in a no/low thust, low speed situation to begin with? Not something I would do, even if I managed to think about it.

They have the aircraft. They have the crew. They have the passengers. The facts will be on the table.

And I still take my hat off to the entire crew of BA 038.

[Dr Brian Evans]

Radio interference may have been part of the problem (laptops or cell phones turned on) - but it would be notoriously difficult to prove. Much lab time and effort is currently being spent in trying to correlate cell phones and lap top WiFi technology with brain cancers - but with no measurable success to date. The BioElectroMagnetics Society in the USA have yet to report any reproducable positive effects - though there have been a number of “one off” reports that defy duplication.

The sceptics bottom line is that if it can’t be reproduced then it didn’t happen. Or did it?

[Bronx]

sandbank

There's nothing special or secret about the probable causes of an aircrash - such incidents are a matter of legitimate public concern. It's quite right that aircrew should be approached for interviews and that the public hears what they have to say.

You're right, there is legitimate public concern. Thats why pilots involved in air accidents are interviewed by trained investigators that are qualified pilots or engineers (or both) whose job it is to produce an independent report for the public - not sell newspapers.

B.

[G-CPTN]

just tried it in the 777 sim...
... and we crashed exactly where they did...

sim visual data base has three low buildings at about 1 mile and we cleared those by maybe 10 feet ....don't know if those exist in the real world.

There's the Air Canada Cargo Facility dead on 1 mile from (normal) 'touch-down' . . .
Others further out are either not directly on flight-line or far enough away to be of no concern . . .
Check here (you can pan and zoom in/out):- http://wikimapia.org/#lat=51.464556&...16&l=0&m=a&v=2

[SaturnV]

FDR and QAR

The B777 FDR measures 700 parameters, the QAR measures 2000. Is fuel temp a parameter measured by either device? What about OAT?

Source:
http://www.asasi.org/papers/2003/Fli...s_Campbell.pdf

[hay diddle diddle]

Come on let face it !!

Engines only stop in flight if they are manually shut down for any reason or they run out of gass!!

The aircraft would not have obtained its design approval if the engines failed through loss of electrical power!!. If any IRE/TRE's are reading this on any type, they should try turning off the electrical power in the sim and landing on the battery. Now, see if your engines respond with manual throttle input, if they don't re check your fuel load or give up flying!!.

I note the initial report said significant amounts, [how can they judge?? welly boots!!] of fuel drained from the number one tank after being ruptured by the left main gear. Well why no fire ?? strange.

The basic engine data on the dfdau or qar will provide the key information on fuel flow TGT and rotor speed plus other related sytem data such as full quantity. Why is it taking so long?? If this is all a bit much, then inspect the engine driven fuel pumps for cavitation [ remember they suck fuel into the engines ]

In low fuel senarios rapid pitch and roll inputs displace the remaining fuel away from the fuel feed path . On a final note why don't they make stack pipes anymore.?? 45 mins at MCT with the fuel low level lights ON!!!!!!!!!!!!! plenty of time.

I am off to have some chocolate licked off me , but it might taste a little different now!!

JNB tomorrow on 4, so Good night and I look forward to the official report in 12 or so months time [ hopfully retired]

[Hand Solo]

The QAR should cover it as in BA I am told they can reproduce every bit of information available to the pilot in the flight deck.

Edit to add in response to HDDs post, pleeaaase, drop the BS 'ran out of fuel' idea. Do you not think that the AAIB saying 'significant' amounts of fuel ran out of the tank is a clue? They are the experts in crawling over bust up aircraft remember including those that don't have any gas left. The crew did not declare any form of emergency related to fuel. The aircraft p****d fuel all over the crash site. The reasonably reliable rumours in BA are that the aircraft landed with over 10 tonnes of fuel on board. Are the AAIB, BA and the crew all in cahoots to conceal a mysterious low fuel state, or is it that something unknown caused this accident?

[parabellum]

I suspect no fire as the bulk of the spilt fuel fell onto the wet grass and mud and by the time the airframe came to a stop there was no ignition source. Pure conjecture on my part.

[WeekendFlyer]

In response to HDD's Post #149:

What are you on about? FADEC controlled engines can fail in all manner of interesting ways if the FADECs do something odd. They are designed not to, but it seems likely to me, from the facts in the public domain to date (including the very carefully worded and excellent AAIB initial report), that something went wrong with the FADECs or another element in the control systems linking the cockpit to the engines. The AAIB report specifically states that the engines failed to respond, NOT that they flamed out, spooled down, went to idle, etc. I cannot believe the aircraft ran short of fuel, as the evidence in the report does not support such a conclusion.

Knowing that the AAIB are very careful with their choice of words in such circumstances, I believe we can take it as read that the engines did just that, i.e. failed to respond. As yet, we don't know what level of thrust they were producing, but by the grace of God it was enough to get the aircraft over the airfield boundary fence.

By the way - all those people who voted "Aliens" in the poll; thank you! It was the best laugh I have had all day

And also, to the chap who said this accident would put pilotless airliners back a few years, I heartily agree with you, and a good thing that is too.

[PJ2]

SaturnV;

The B777 FDR measures 700 parameters, the QAR measures 2000. Is fuel temp a parameter measured by either device? What about OAT?

The QAR (for SESMA/FDM/FOQA work) will record as many parameters as the installed data frame is designed for, (QAR software) and at sample rates that the frame is similarly designed for. The DFDR is capable of this as well but typically DFDR data frames are smaller and at less frequent sample rates for many parameters. Sample rates of 16 frames per second are possible but are expensive in terms of storage and recording capability. Sample rates from once every fourth second to eight times per second are common in both DFDR and QAR dataframes.

All this is by way of clarifying that "700 parameters" and "2000 parameters" is not a fixed, determined number. Our own 777 QARS are taking in more than 2600 parameters and our 320 dataframe provides us with over 1700 parameters, far more than the DFDR.

More difficult to program, are text-string based parameters to record EICAS/ECAM messages and FMGC entries and readings. Not all ECAM messages are recorded I know, and I suspect not all EICAS messages are recorded either.

Very good animations may be created from such rich data-sources - I suspect this was done within hours of retrieval of the recorders, including the QAR which I would expect to be in good shape.

[SaturnV]

Another question:

For those familiar with the usual practice of the AAIB, is it likely that an interim report with additional details from the FDR, e.g., a more detailed flight profile during the descent phase, will be issued before the 30 day report?

I presume if a likely cause is found near-term, and which necessitates an AD or a SB, that the AAIB would issue an interim report (with relevant flight data) that supports the issuance of an AD or SB.

And is it fair to assume that if the AAIB waits 30 days before its next report, that the incident will ultimately be seen as a one-off?

[KC135777]

I've been told- that much condensation was found to be in the E&E compartment... therefore, possible electrical shorting of the fuel control units- rendering autothrottle commands/throttle inputs useless.

Anyway, something to chew on...........

[Lemurian]

post paste

It is really amazing that the theory of a double flame-out, for fuel exhaustion / pollution /icing-waxing, keep turning up in spite of the information that has been given to us.
What we know, from the AAIB, is
The F/O was handling the approach (Question : A/P on or manual with FD ? )
Down to a height of 600 ft, the approach parameters were quite normal.
The engines were not responding to throttle demands (Question : One or both ? )
The aircraft was in a low energy state (Question : Due to the insufficient engine (s) output ?)

What we do know :
The aircrew has had a long 12-hour daylight flight before their approach to Heathrow and were probably past their peak of alertness.
The aircraft went below the ILS glideslope and touched-down 100 ft below said glide. That's not very much, if one puts the events into perspective.
The weather conditions were fair but there had been a forecast of instability and possible windshear over the British Isles on the zones ahead of a frontal occlusion and throughs.
There have been some instances of engines on the 777 not respoding to throttle commands. To the effect that there is a procedure to that effect. (granted, GE, not RR ).
My argument lies on the premise that a *hung thrust* is very hard to detect from a pilot's point of view. One would start to notice it, as the failure is in essence very subtle, only when the thrust demand becomes rather high, relatively to a normal required engine EPR.
As a matter of fact, if one omits the speed tape, all the approach parameters would seem normal : On the glide, FD bars crossed in the center of the PFD, EPRs coherent with the approach conditions. The only other visible clue that something is becoming quite wrong would also be the unusual pitch attitude, somewhat higher than normal, but the clue would be easily hidden by the *normallly*crossed command bars of the FD.
We now have the beginning of the ever worsening trap we all dread : A decaying airspeed, an increasing drag situation requiring more thrust that is not available any more which causes the speed to decay further while the AoA is increasing to achieve the "stay on glide" requirement...and so on....
At that point, the thrust required for exiting the situation would have been very important and from a piloting aspect we are probably close to a stall recovery-type of handling.
That close to the ground ? IMHO, some feat of reflex-flying !

Did I forget to say that as the F/O was handling the aircraft, that information taken in itself destroys the ideas of a double engine flame-out, as in this case, the only instruments available through the battery, would have been the captain's ? And neither the APU or the RAT would have enough time to come on-line.

[DingerX]

Yeah, double flame-out is not much of an option.

48-hour and 30-day reports are mandated. They could "find" something before after that necessitates immediate action; there's no reason it has to happen before or after either of these gates.

As for the "Dog and Pony Shows" of BA presenting some of the crew: there's no need to suggest that means they were or were not heroes (although the initial report makes it difficult to suspect they were at fault). But, in a moment when the press is desperate for something, sometimes chucking them the least bone possible helps. Situations like this are huge information vacuums, and the slightest whisper will be amplified to huge proportions. If you give the press access to authorities quoting non-controversial facts (Such as "It was a team effort"), you give them something to say without forcing them to probe the web forums (and come up with lines such as "unlike their commentary on any thread involving Iberia pilots, Ppruners were unequivocal in their praise for the pilots").

So, in short, don't read anything into the presentation or not of the crew to the press. It's not dictated by the facts, but by PR strategy.

[Hand Solo]

I have good reason to believe DingerX has hit the nail on the head PR-wise. The press in the UK are notoriously immoral and intrusive. If you give them nothing they'll take something. Best to be in control.

[huggychair]

I Think that Riverman (post #137) may be on the money here, icing may not have been an immediate issue here but a contributory one to the sensor points/connections (moisture).

The fact that it was picked up by the FAA on the G.E. powerplant rather than a Rolls-Royce one (on the same aircraft design) should make little difference to the underlying cause. Just because the FAA didn't put out an APB on the Trent engine doesn't mean they're infallible to the same control/FADEC issues!... it just meant they hadn't dealt with them at that time.

Operators with RR's would have looked away (understandably), but the FAA's remit was only to explore what was going on in ITS (much bigger) aviation industry, where G.E. engines dominate, and had lead to previous (unrelated) issues (IIRC)...

And if this BA workhorse 'was' doing the same route fequently, then it looks likely (reading some of the above route-based posts) that moisture could have been a <contributory> cause in losing control ...at that time of descent, whilst the fuel pressure/electricals were working overtime!

just my 2p's worth!

[d71146]

The Press Conference

I don't think anyone can deny that for whatever the outcome of the AAIB report brings the flight crew did an outstanding job in landing the 777 and everyone getting out alive but what puzzles me is the press conference held by the airline persuading the flight crew to give a statement about the incident I just hope that it does not come back to bite them on the bottom.
I myself think that perhaps just naming the crew and showing their photos would have been quite sufficient and leave it at that but, perhaps I am a tad old fashioned in this respect.