BWBriscoe

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

sispanys ria

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.

TheShadow

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.

philipat

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?

sispanys ria

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 ?

vapilot2004

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.

Contacttower

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.

BAe146s make me cry

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???

sispanys ria

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...

philipat

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

L337

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.

wilyflier

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

TheShadow

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.

HarryMann

This crossed my mind too...

dxzh

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?

dxzh

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.

Rainboe

zzzzzzzzzzzzzzzzzzzzzzz

Yellow Shark

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

dxzh

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.

suninmyeyes

I totally agree with Rainboe. Two 777 training Captains who recreated it in the sim with the data available, ZFW, fuel, Flap 30 Vref (constant wind used as cannot simulate gusting winds) noted that from "Hang on, what's going on here" to hitting the grass was just 25 seconds. Once they had come to a stop just short of 27L there was a stunned sense of disbelief. Now bear in mind this was just a simulator, no life endangerment, and these pilots were expecting it. As soon as the power comes off the nose immediately pitches up rapidly to maintain the glideslope.Speed comes back to about 105 knots. Lowering the nose towards the horizon to regain lost speed results in an immediate descent rate of about 2,800 fpm. Not much fun in a widebodied jet at 500 feet with full flap. I would hate to think of the rate of descent if you lowered it below the horizon. I am amazed at the number of things different people on this forum have said the 038 pilots should have done in those 25 seconds. The pilots never claimed to be heroes.

Incidentally a lot of professional pilots do not disclose inside knowledge on this forum because the non qualified theorists like to challenge it, or correct it which is irritating to professionals. A little knowledge is a dangerous thing. Airlines are very safe but leaking information outside the industry can give the wrong impression. An example of this is MEL items and the outrage it created on the Spanair thread. Or an example outside aviation: You try telling someone who has never been in a car that during rush hour these things that weigh 1500 kgs go onto roundabouts at 30mph and miss other cars by only 3 seconds, or drive down motorways sometimes with separation times of only 2 seconds and you have blindspots where the driver cannot see cars behind him. There would be uproar, non-drivers on car rumour forums would say passengers should at all times observe the blind spot and warn the driver and all speed limits should be reduced by 50% to enhance safety. Flying is very safe. Leave it to the professionals.