In spite of many months of investigations and now the AAIB preliminary findings, talking to my Flight Crew colleagues on the 777, none of them seem to believe that ice was the problem.

VC10's in the 60's used to fly reglularly over 40,000 feet. There did not seem to be any problems with fuel icing in those days?

Ice or ??
 

Poof in Boots,

"In spite of many months of investigations and now the AAIB preliminary findings, talking to my Flight Crew colleagues on the 777, none of them seem to believe that ice was the problem."

OK then: what DO your colleagues believe was the problem?

BA Engineering maintenance is under scrutiny at present due
to a variety of non-compliances raised in the form of reports
to CHIRP. The Engineering Director at CHIRP is incidentally
ex-BA. UKCAA SRG (Many ex-BA staff) have yet to comment.

On commercial aircraft, routine maintenance is performed daily.
The time intervals of daily routine maintenance cannot be deferred.
These tasks would include the draining of water from fuel tanks
IAW the Aircraft Maintenance Manual.

I would hope that attitudes to task completion have not altered significantly since I worked there. Documentation & certification of all tasks undertaken must be recorded. AAIB must ensure previous draining
of fuel tanks tasks for this A/C were actually completed (Not simply penned off).

BAe146??? :{:{:{

What exactly are you insinuating? There is not only no suggestion that this is the case, but this is extremely off-topic when the recent report has narrowed down the investigation to some very specfic areas. Further, the non-compliance to which you refer did not to my knowledge ever relate to tasks not being completed and later falsified, but instead to people of incorrect qualification working on tasks at Cardiff.

Judicious deletion of irrelevant posts from the moderator please?

Flight safety is not decided by poll taking.

Questions are natural as this thread has proven. However, when Service Bulletins are issued by the manufacturers and/or authorities they should be complied with.

When the pilot community have questions about the application of a SB that is the responsibilty of the issuer to defend.

Many questions remain and hopefully many will be answered in time. However as some are answered then solid recommendations will be issued.

Grebllaw123d:

In answer to your question, I suggest you read the whole thread again.There are plenty of alternative suggestions as to the cause....

RE-HEAT

Please step down from the box. This is a public forum and
as such, informed opinions from people in industry (or otherwise)
can and should be aired and shared.

There appear to be fundamental problems with how BA Engineering operates at present. This has been initiated by concerned BA maintenance
personnel.

Some of the best Licenced Aircraft Engineers remain at BA Engineering, however, not many as so many have chosen to leave. In closing,
the compliance or deviation of/from AMM practices & company SOPs within BA Engineering, early 2008 shall always be relevant to the
loss of this B777...

BAe146??? :{:{:{

ice?
 

I don't have any technical knowledge like other who have posted here, however, I've been flying transport jets myself since 1978, current wide body captain, and I've never heard of fuel icing of this nature. Certainly, in most cases, such an occurrence would not be a one time thing, considering how many hours are flown each day by different types of aircraft exposed to different cruise altitudes temps and fuel loading conditions; if anyone has any knowledge of a previous occurrence, that might add some credence to this scenario....:bored:

SLF here. I've avoided any comment until now because I have no knowledge to add to the topic.

However, one thing I can say is that my faith in the 777 is in no way dented and I happily fly that plane. One isolated incident does not a pattern make.

Bob

One theory being propogated is that the incident was more to do with the software....ie: the lines of software code.

Perhaps on the BA038, glitches buried somewhere in all those lines of software code came together like holes in a cheese......

dear PinB,

I am one of your 777 Flight Crew and as such used to believe that it might be an EEC software error however the NEW AAIB report clearly narrows the possible cause down to one specific area.
Software errors always happen, on any plane so it would have been plausible.
The AAIB wouldn't have written this report without proving that another error would have been a better fit for what has happened.

Fact of the matter is we don't know how ice behaves at high altitude at extreme low temperatus in a complex mix of JetA1.
Certainly in my mind we can put the software glitch to bed.

PinB:

Head back to post #1661 and you'll find a series of posts from one of the guys who worked on the RR FADEC system. The whole discussion was pretty much encapsulated there.

'Fact of the matter is we don't know how ice behaves at high altitude at extreme low temperatus in a complex mix of JetA1.'


I find this statement, if true, to be extremely worrying. I mean haven't we been flying for many, many years with JetA1 at high altitude and extremely low temperatures or am I missing something?

Water in Jet A1
 

Some of the physics of water in Jet A1 at www.facetinternational.net/pdfs/aviation/aircraft_refueling.pdf It would appear that the behaviour of water as the fuel temperature falls is understood.
Back at the AAIB report graph on page 5. (bottom rt hand corner, enlarge to 800% for a clear view) Does anyone understand why the fuel consumption from the left hand main tank increased immediately after the scavenge from the centre tank. This following 7 hours when the fuel consumption from both tanks was identical?

Scrivenger .. actually, its worse than you think!
 

It is true that the AAIB report that 'little is known' about ice crystals in fuel at temperatures below 18C (0F) - see my post 1725,page 87.

Its worse because the AAIB don't mention the overall operating environment, just temperature and not pressure, vibration, fluid circulation etc..

This is not meant to imply any wrongdoing on the part of the AAIB. Actually, I suspect that if you were to have a private conversation with the AAIB report writers the air would turn blue if you asked them to describe the industry's fuel standards. I wonder when the AAIB realised that 'the standard' has a huge whole in it.

But, has the industry simply lost or forgotten the knowledge that may have been gained from tests/experiments etc. conducted decades ago?

Some older crew have already posted here .... can anyone shed light on fuel tests back in the '50s and '60s that lead to the development of the fuel standards?

Regards, Tanimbar

Oilandgasman ...
 

Thanks for the link to the PDF from Clarcor. Just read it and it doesn't help us understand the behaviour of water in fuel as the temperature drops, other than in a general way.

Clarcor, as you know, make fuel filters and systems for ground based operations - storage of, transport of and re-fueling of aircraft. Fascinating to read that Fuller's Earth is still used as surfactant. Now that is an example of modern technology using knowledge gained centuries ago.

The discussion on microbes in tanks was interesting too.

Regards, Tanimbar

Tanimbar
The section I thought may be relevant concerns precipition of absorbed water from Jet A1 as the temp falls. This precipited water will form droplets then sink to the bottom of the tank. SG of Jet A1 0.78-0.80. Ice 0.9-0.95? In the case in point this precipited water will be in the form of ice crystals. Note your comments on microbes. If tanks are not treated with biocide during cleaning then they are another matter, will be present if water present, but are easily identified under the microscope. This must have been checked post incident as they are a well documented contaminant as are fungal spores.
The bottom line is that in the first sentence of ASTM spec for Jet A1, includes the phrase " bright, clear, and FREE from water". Not drops, not ppm, not entrained...none. If this is not what is being delivered on every occasion then there is a quality control issue.

dxzh
Do you give any credit to what you call that apparently FAA leaked memo

Therefore what do you think of the AAIB reports which do not mention:
- A maintenance message indicating excessive water in the center tank set during taxi on the two previous flight legs
- An auxiliary power unit (APU) auto start sequence
- A crossfeed valve opening

M.Mouse
As you correctly mentionned the fuel on board and the flap retraction before the AAIB did confirm your words, would you like to comment on that apprently FAA leaked memo ?

CONF iture,

I am certainly now prepared to give more credence to the "apparently leaked" FAA memo dated 24 January 2008 (which popped up on the internet by 1 February 2008). This is because the purported inside knowledge in the memo of what seemed to be non-public, pertinent information at that stage of the investigation has been subsequently corroborated in many varied respects by information in the AAIB's later bulletins and reports. Was the memo as leaked only a draft (or even a forgery) I do not know - however, I try to note well the cautionary words drummed into us by PPRuNe about not taking everything at face value and hence I wrote "apparently". The memo itself ends with the words "Information only. This information is preliminary and is subject to change". If very curious about the memo's provenance, maybe the answer is for some brave soul to pick up the phone to its supposed author, Doug Pegors, and ask him - his direct line at the FAA is publicly available.

As regards the AAIB reports to date, I believe they are concise and well-written, concentrating correctly on the contributory factors to the underlying accident, rather than the consequent events as the aircraft impacted the ground. Actions at the time of impact may not be wholly irrelevant in so far as they may reflect on the status and set-up of the aircraft on or prior to the underlying accident. However, the key concern here is to understand the unheard of rollback of each of two seemingly fully-functioning engines at a critical stage of flight. I am not surprised that the AAIB's clear focus is on understanding the duplicated rollback and how to avoid a double failure condition in the future.

There are clearly gigabytes (let alone pages) of raw data and analysis which could be made public but that would be a disclosure exercise of an altogether different quality and for a very different purpose - this investigation is not the subject of some hugely expensive public enquiry or court case (thank goodness) and, as ever, safety in aviation has generally benefitted from measured disclosure of facts concentrating on solutions and not scapegoats and thereby encouraged full and frank offline discussions with accident investigators (rather than a**e covering for fear of litigation and a blame culture). The AAIB has already disclosed much more than it might have, but given the degree of rumours and speculation perhaps a balance has had to be struck.

Am I surprised or concerned that I have not received a download of all the data in the QAR, FDR and NVM or test rig papers etc? No. Am I surprised or concerned that the AAIB may omit from the 21 page interim report certain information about events which I assume the AAIB is confident happened on or about impact (perhaps technically part of flight until aircraft stationary, perhaps interesting to a pilot, but not relevant to the focus of the investigation)? No. Am I concerned that information in earlier AAIB bulletins such as about FOD (eg plastic scraper) has not made it into the interim report? No. In fact I really believe the AAIB is doing a great job synthesising the information and keeping the correct focus on the critical failure condition.

Nevertheless, I do speculate about the uncorroborated centre tank messages even though I can understand why if they did exist the AAIB might have discounted their evidential importance given the sumping and, perhaps, a suspicion that the message is not as reliable as it might be and it would consequently be misleading to draw from it a conclusion that there really was 600+ litres of free water in the centre tank! On the point of water in the centre tank (as opposed to the omission of messages (if there were any, I stress) from the interim report), I feel a little rebellious as water in any tank bears on the underlying accident, even without any suggestion of such a message, and to my mind there is circumstantial evidence in the design and track record of 777 centre tanks suggesting a tendency to accrue ice and free water there. There is even in the (apparently leaked) FAA memo a second statement of information learnt on 22 January 2008 that "There was a message of water in the center fuel tank shortly after departure from Beijing." - ie implying that not just on the two previous legs, as learnt on 24 January 2008, but on the actual accident flight there might have been some ice which melted into free water in the centre tank. I could envisage a scenario along the lines of: existing ice already in the centre tank is gradually melted following the uplift of warm RP-3 fuel; the resulting free water triggers a message; and sufficient free water is then dissolved back into the bulk of the fuel by the water scavenge pumps' operation to clear the message.

As to the APU start sequence (around termination of QAR recording) and cross feed valve, I am very curious and have lots of questions and ideas, but I personally see little relevance to the real focus of the investigation even assuming as I do what is stated in that apparent FAA memo is not complete fiction - to the extent either were involved in events after the dual rollback process had started, I strongly suspect that the AAIB would see them as playing a secondary role and the data bears out that there was a much bigger issue already playing out - namely a critical restriction in both fuel lines.

BAe146s make me cry

I respectfully request you wind your neck in and start a fresh thread in the Engineering section of these forums if you have an axe to grind.

I'm not sure what your agenda is here but it's clear that the AAIB do not feel BAs Engineering or Flight Crew were the cause of this accident. I'm further confused by you're insinuation that BA Engineers deviatied from the AMM with regards to this aircraft. Also for you to even suggest that this task was "penned off" is a terrible accusation from a fellow member of the engineering community founded on not a shred of evidence.

These may be talking points and forums for discussion but you really need to be careful when slinging mud in a direction it is not deserved. :=

Have any measures been put in place operationally following the report?

And do you believe in Santa Claus ? The reason why many countries are usually disclosing the raw recorded information is to avoid the investigations to be questioned. I'm glad you believe whatever is submitted to you but what will happen if (God forbid!) one day the AAIB is releasing inaccurate info ?

When I read this report and know that the crew got rewarded as heroes I really have the feeling of a bad joke. They certainly did save the day by finally reducing the AOA when the aircraft was stalling, but that's what any pilot is supposed to do as a very basic reflex. As a result I don't see heroes but only pilots who were probably surprised after a long flight and who did their best according to their perception of the situation. But no heroic behavior (at least not in what the report is stating about retracting flaps under AP and low energy conditions and aiming 300 m beyond the threshold...). Even with fully disclosed raw information many investigation autorities did already manage to release BS, what would make the AAIB so different ?
I recommend you to read the concord report, you would then understand how easy it is to use the raw data to realize the investigators are sometimes having very curious interpretations... Welcome to neverland.

Some Conclusions are Easy......
 

My reading of the highlights from the initial FAA Report on Flt BA038 (below) is that:

a. There were center-tank water warnings on the previous two flights - as well as on the accident flight ex Beijing.

b. These were not unusual events and usually gave rise to a routine "sumping" to clear any collected water within range of the low-point drains.

c. Water warnings usually indicated (by design) a significant amount of water in the tanks.

d. Because the nature of the warnings were usually that they would appear and then self-clear, the 777's system had gained a reputation of intermittency and fallibility. It was generally believed to be flaky, unreliable and therefore no great cause for concern - beyond generating a requirement for a sumping post-flight.

However what may have been the case was that water in the fuel was circulating (courtesy of pumping and refueling) alternately into and then away from areas covered by the water warning sensors. Additionally (and frequently) the water would also (either) become dissolved in the fuel or freeze in non-designed water-trap areas and no longer be detectable as water. This would explain the (perhaps undeserved) reputation of the water detecting system as being unreliable and inconsistent. The attitude adopted by engineers would have been to respond to reported/recorded "water in tank" warnings by simply sumping (draining) from tank low-points at the next turnaround servicing. Self-evidently this would be totally ineffective if done soon after a long-haul high-level leg (water still frozen) OR soon after refueling (water redistributed by the refueling operation to areas well away from tank low-point sumping drain-valves - as well as being to some extent re-dissolved hygroscopically in the swirling warmer fresh fuel. It should be noted that water-detection IS traditionally done soon after refueling - and that may not be any longer such a good idea. Because the Beijing overnight was in sub-zero conditions, sumping would've been quite unproductive, even though fuel would have deceptively emerged quite water-free from the drain-points. At Heathrow, after the accident, the center-tank was ruptured (see FAA report below) and all the residual fuel was lost - including, it's presumed, any/all water evidence. Without clear data, the UKAAIB's bottom line would necessarily have to be quite conjectural. Boeing wouldn't abide by (and would vigorously contest) any proposal to redesign tanks, pumps, piping, filters and water-traps. The bottom line is most likely to be a greater constraint upon TAT's at which the 777 can operate. Longer legs in low outside temps will be flown at lower, less economic, altitudes.

The highest hazard area during a "latent" (dormant) water-carrying flight would be precisely as in the BA038 scenario, i.e. the center-tank fuel level is low and the water melting during descent and the detached lumps of ice moving towards engine-feed pump inlet ports courtesy of pump-suction, higher engine fuel demands (spool up during aircraft attitude changes - both on descent and on finals when configuring with gear and flap).

One further thought. How will the formula for fuel absorption of water change once tanks are nitrogen inerted? Will it be a catalyst effect (i.e. dissolved water being more prone to precipitate out and collect and freeze at low points) - or will there be a positive effect? Would it be possible to capture the (presently wasted) oxygen by-product of the NEA process and utilize it for fuel-warming? My guess is that the result of BA038's accident will be a token SOP change, a limitation on cruising at low ambient temperatures and an overall inconclusive and unsatisfying bottom line.

AAIB
 

I do have very great faith in the AAIB. Together with the support from FAA and Boeing, it is difficult to imagine more expertise being available for an investigation. So I do believe that the iceing scenario is accurate and correct. It does just somehow continue to bother me, however :

1. Why has this never happened before during millions of longhaul flights in very cold conditions. Yes I know that there is always a first time for the holes in the Swiss cheese to align, but it still seems somehow improbable, logically speaking. Is the design of the RR Trent and FF so different from earlier designs and from GE/Pratt kit?
2. Repeat question to the 777 experts. Have the earlier incidents of failure to deliver commanded thrust been adequately explained?

Faith has nothing to do with aviation matters. In aviation you know or you don't know. Saying you believe is meaning less. You should ask yourself why when concorde had dozens of incidents similar to the one which caused the fatal accident nobody moved. The NTSB made extremely precise recommendations in the 80s which were not considered by none of the manufacturer, the registery states, the operators, the investigation boards (including the AAIB). What faith are you talking about ?

As far as I know, the one-engine rollbacks have been attributed to software in the EEC and have not re-occurred since the updates were changed.

It's called reputation; the AAIB has over the years produced many reports of very high quality which have changed and improved the way planes are made and the way we fly. They deserve our trust.

Fargoo

No axe & no agenda. Your employer, our NAA & CHIRP have issues
that are likely to have contributed to this incident, a culture if you will - Too Cozy?

That same culture has possibly led you to believe specific tasks are
never 'penned off' in Base or on the Line - I certainly do not approve of the practice BUT it happens. Everywhere I have worked (including BA), despite ALL airworthiness requirements and HF rhetoric 2008, it still happens as no a/c engineer is immune to commercial pressure. There
is also the issue of BA supervision of techs/mechs, line & base. However,
this is not the place to digress.

As a fellow a/c engineer, I hope for nothing more than a full answer from the AAIB for this incident to prevent re-occurence :. I shall return to the Engineering Section as requested. For now.

BAe146??? :{:{:{

Once again, trust doesn't have anything to do with investigations. We are talking about facts. Investigations' raw info is to be publicly available to ensure transparency.
What kind of reputation do you refer to when considering none of your "high quality" reports has been released following the dozens of concorde's tires accidents, especially when this is seriously recommended by the NTSB ? As far as I know, one's reputation is presumed good until it's no more...

Apologies for poorly selected language, but that is exactly what I meant to say.

It is perhaps worth saying that allot of information has been made available to BA aircrew. Some of that information, such as the flap retraction, made it to pprune.

It interesting that despite BA having some 3000 pilots, very little "inside" information has made it to this forum.

ref post 1883 The Shadow
 

Please may I remind The Shadow ,(his middle big paragraph), that the fuel uplift was NOT warm. I recollect a post stating it to have been minus 10 degrees C

Everything's Relative.....
 

But it may well have been "warmer" - as the post says......

Warmer stirred fuel added via refuel would tend to "soak up" ice-melt inside the tanks and perhaps invalidate any sumping.

This crossed my mind too...

sispanys ria

Thank you for your message. In response:

- I do not believe in Santa Claus.
- "many countries" do not have the expertise to analyse the raw data, hence they may release the information to professional bodies such as AAIB or NTSB for evaluation - I believe we are fortunate to have the likes of the AAIB and the NTSB.
- I have tried to make clear that I do not believe everything, hence my evident scepticism about the apparent FAA memo, particularly initially - I try to have an open mind, even about other posters on this forum who can appear less dispassionate but nonetheless are only expressing their own genuine belief or suspicion.
- I am more concerned with the information already released and how accurate that is, since my interest is the conundrum which is the double failure condition demonstrated a minute out from landing at LHR, rather than events however interesting occurring afterwards.

- as regards your second paragraph, I have no doubt you read the report and, judging from your previous posts on this and the "BA crew gets medal" thread, you are upset that the AAIB has not published and commented more on the crew's actions - indeed, I cringe on your behalf at some of the hard (verbal) knocks you have taken.
- I believe you are mistaken in conflating your comment about "rewarded as heroes" with the AAIB, though given your belief I can understand why you are so passionate about challenging the apparent status quo.
- I appreciate your comment that the pilots "certainly did save the day", and perhaps in the maelstrom of attention after the event that was the media message, however clumsily stage-managed, that BA were trying to put across - and which the media unsurprisingly hyped as heroics.
- I note your continued challenge of the pilots' behaviour as deserving of a "heroic" standard. My gut view is that in a media age in the UK where people in the news tend to be characterised as either a hero or a villain (with no nuanced or neutral position in between), I can understand why BA, in supporting its brand and its crew, steered the story in the media towards the "hero" characterisation (by awarding a medal), even though I would be more inclined to express it in this forum as you did that they "certainly saved the day".
- I note your comments about flaps, AP and aiming point and, while I would not dismiss them, I am glad that the AAIB is concentrating on the primary issue here which is the double failure condition.
- I have few comments on this secondary issue of the impact other than to say with low energy, gear down, turbulence and a crosswind, I agree that the crew's actions saved the day by making a more than sufficiently controlled landing such that the hull survived and everyone walked away (or hobbled in the case of the person with a broken leg). I repeat that in my view to have a result like that in the circumstances they did a great job. It will not be possible to show that any other combination for landing would result with 100% certainty in an "as successful" non-fatal landing so, as a critique of the BA pilots' behaviour on the day, trying to show a better way of handling the aircraft is futile and risks becoming a mud-slinging exercise to be picked up by the media and against which the pilots concerned would have no ability to defend (not nice, and I assume why your genuine comments have at times been treated dismissively (also not nice)). That is not to say that you are right or wrong or that another thread on low, slow, heavy commercial jet, engine out landings would not be well read or of real interest.
- I note your lack of faith in other investigative authorities but see it as having no bearing on the professionalism and internationally recognised expertise of the AAIB, and the practical point that it is working hand in hand with the NTSB, Boeing and others.
- I have read the English version of the Concorde report previously. I would highlight to you that for many the key point coming out of the report was the analysis of the chain of contributory factors leading to the fire, rather than the way in which the crew thereafter tried to keep the aircraft airborne prior to it impacting the ground. The same point applies to the priority in this investigation.
- I have not assumed that investigators cannot get it wrong and I too will feel free to question their opinions if I believe I have the time and an important enough reason to do so - I repeat though that I genuinely believe that the AAIB have had the right focus and the crew did a fantastic job, saving the day.
- thank you for welcoming me to Neverland, but I think you have the wrong person - may I also take it you are not Michael Jackson incognito?

The interim report states that the No.3 Jet Fuel uplifted was at +5C (see page 10 of interim report).

The centre tank was empty prior to the uplift, save for any ice which, especially if in contact with the uplifted fuel, might slowly melt but presumably without reducing materially the bulk of the centre tank fuel's temperature below +5C.

The main tanks still each contained 4 tons or so of fuel (seemingly from Figure 1 of report at -20C at least in left hand main tank). After the uplift of another 25 tons or so of fuel into each main tank at +5C, the left hand main tank temperature was never higher than -1C, hence it seems the main tank fuel temperature remained below water freezing temperature during, and for last two sectors (at least shortly after leaving LHR) either side of, turnaround in Beijing.

zzzzzzzzzzzzzzzzzzzzzzz

So what format do you think the FDR data comes in?

Rainboe, I am beware but no good at the fire and brimstone. As I was "engaged", I just wanted to respond in a hopefully constructive fashion. My view is simple:

- the crew did a great job, together saving the day, getting the plane safely on the ground; and

- the expertise of the AAIB is correctly focussed on the contributory factors to what was a potentially catastrophic double rollback.