BA038 Crew get BA safety Medal

[M.Mouse]

I hesitate to continue this debate but I will make one last posting describing what was possible in the simulator after several attempts and considerable thought and discussion. Before I go on the B777 does not have the normal pitch/power couple so familiar to pilots of earlier Boeings due to its semi-automatic trimming system.

At the moment of power failure reduce flaps from F30 to F20 and at the same time lower the nose to accelerate and recover some of the lift lost from the flap reduction. Once into ground effect (approx. 200' on a B777) fly level and as the speed decays take further stages of flap until back to F30. The aircraft will reach the threshold of the runway. It worked in the simulator.

The visual picture looks awful and it would take a brave and skilled individual with perhaps superhuman speed of analysis to have pulled of such a feat bearing in mind the crew had no pre-warning and less than a minute to deal with the unthinkable. Which is why I have refrained from the debate up until now lest I am seen to be criticising the crew of the BA38, which I am most definitely not.

A very good explanation of ground effect and its benefits and disadvantages is shown here: Ground Effect explained and will help understanding of why the above would work.

[cwatters]

So let me get this straight.... They reduced flap to improve glide.... they traded as much speed for height as possible and they were STILL low over the fence? It sounds to me like they had no option but to "hold it up".

Had they dropped it in further into the field with a high rate of descent then I guess you could argue that they held it up too long but that's not what happened. They held it up and only just made it.

Had they immediatly dived while the flap were still fully down I suspect they would just have lost height and not increased speed much? Comments?

[Rainboe]

Interesting. But what you are saying is basically that the energy loss of losing power on final approach from 700'+ would only account for an undershoot of a few hundred feet and a speed loss back to 108kts or so. I wish I could see it! Not something I would dare have done in a 747. Pre-warned and pre-armed maybe it could become a procedure, but totally unexpected and out of the blue, an unprecedented incident like this on a wide body, I have nothing but admiration for a magnificent achievement as it stands.

[dxzh]

I am really pleased that both pilots and cabin crew have already received a medal - through a combination of professional skill, good fortune and great CRM they pulled off a safe landing after being dealt a potentially catastophic hand of power loss at low height.

As an aside, another real-life example of the conundrum of energy management following a loss of power at low height (caused by very different factors but with happily safe results also), was the MD-83 at Bradley, CT in 1995. In that case the pilots decided to balloon the aircraft by setting 40 degrees of flap ... I believe the left engine had failed and the right engine was failing and in the later stage of the incident the plane apparently clipped a tree 76 feet above the ground (tree at 170 feet msl), some 1,100 feet from where it subsequently touched down on the ILS antenna and then rolled onto the runway (at 175 feet msl). The pilots in that case too were justifiably praised for getting the airplane down safely in that rather different set of circumstances.

[sispanys ria]

Would any pilot, with engines unexpectedly failed, at that altitude actually throw the nose down. I don't see how after the loss of energy from those engines from the time of failure sometime above 800', they could have got the aeroplane the extra distance to the threshold no matter how they played it, even at 108kts. I would be most interested in hearing how it should be done!

Dear Rainboe, it is incorrect to continue exaggerating the pushing the nose down story. Nobody ever mentioned to push on the stick. So without pushing on the nose, you still have different options from pulling on the nose without power (which is what was done by the AP to keep on the glide). Without pushing on the stick, it is true that the nose would go down but I suppose the maintained speed would probably allow a controlled flare.

As I told you in my PM, on smaller aircrafts it is recommended to trade some potential energy (height) into kinetic energy (speed) until approaching the ground effect height. Once reaching the ground effect height, level flight should be maintained and flaps extended to full accordingly (flaps are extending gliding distance during a short period followed by highly deteriorated gliding performances). The speed reduction resulting from this level flight should allow a controlled flare until impact at a low speed and low fpm.

Once again, I'm not pretending this can be applied to heavy aircrafts, and anyway this wouldn't have been possible for this crew due to the extremely short time of reaction. Despite this, I'm quite surprised by the pull on the nose option and this is why I wanted experienced people to elaborate on it since I would never believe that pulling on the nose could be considered when loosing power.

[Rainboe]

dxzh, sounds a good idea. In a crash, not surprisingly, it is the kinetic energy that kills you. Anything you can do to reduce impact velocity increases your odds of survival. The conversion of kinetic energy to destructive force varies with the speed squared, so it is all important to contact the ground with minimal speed. Full Flap and just above stall speed seems a good idea, and the gear down getting knocked off helps dissipate the kinetic energy.....which in this case is what they did to a 'T'. Shame he's still carping on about it, whatever he is saying!

[lomapaseo]

Anything you can do to reduce impact velocity increases your odds of survival. The conversion of kinetic energy to destructive force varies with the speed squared, so it is all important to contact the ground with minimal speed.

Well decelleration forces have a great deal to do with this.

So in a what-if mode

Spread the slow down in speed out over a longer time and you have a much greater chance.

So strewing parts of the plane along the horriz path aint a bad idea, but the major issue in these cases is the weakest link that breaches the cabin assuming the fuel tanks are breached.

If you can drop it vertically (stall) and stay within the drop test g loads demonstrated during design, I'll take that.

If not then spread out the horrz G's along a straight line ala the Kallita B747 and AF Dover C5. But don't skid it sideways.

I'm guessing that the pilot senses too much unknowns about the vertical drop rate and impact G's and chooses instead to spread out the G's in the direction of flight that he has more control over.

So what do most of you do in simulators in this altitude regime when you lose it? and don't tell me you don't lose it because we all like to feel what it's like in a simulator don't we?

[Rainboe]

Low altitude stalls are too unpredictable to risk voluntarily contacting the ground in a stall regime. We've had losses of a 1-11 and Trident in vertical fall horizontal attitude stalls, with no survivors. The idea is to keep flying just above stall- 108kts sounds about right! You need to keep attitude control to the end. It's all very well coming out with criticism of better ways, but this was a unique event, and I would have written off throwing the nose down with at the back of my mind these thoughts:
'With flap running in and out, will I still have hydraulic pressure to power the elevators with the load I will need to pull out of this self inflicted dive, and can I risk running flap at 200' with a very large elevator demand still to come?' They had precisely 0 seconds to make that choice. On a 747, I'd have said 'no way Jose!' The whole plane load is walking around today. That is why they deserve respec', big time, and that is why these pathetic gits who carp on about them even now should have the ignore button pressed on them!

[Conan The Barber]

It is rather bizarre to equate a desire to learn and improve with critisism.

To analyze a situation and see if it could have been handled differently, possibly resulting in a more favourbale outcome, is a natural and healthy thing to do. How this can be seen as critisism is beyond me.

I still don't know what effect the crew's actions had on the outcome, if any. So I won't offer any comment in that regard.

[Rainboe]

To analyze a situation and see if it could have been handled differently, possibly resulting in a more favourbale outcome, is a natural and healthy thing to do. How this can be seen as critisism is beyond me.

Exactly, post 121 above, is an example. But there is a negative aspect. To observe it, hit Search and input Sispanys Ria for someone who knows how to do it better and has no qualms about saying it.

[lomapaseo]

Low altitude stalls are too unpredictable to risk voluntarily contacting the ground in a stall regime. We've had losses of a 1-11 and Trident in vertical fall horizontal attitude stalls, with no survivors. The idea is to keep flying just above stall- 108kts sounds about right! You need to keep attitude control to the end.

I agree with this and just wanted to take it a bit farther with the zero seconds intuition of horriz flight as the primary concern, avoiding stall as the secondary concern and then if you still have a flying machine (you're still in control) some second order considerations like a lot of us are second guessing

Of course I and just about everybody else on this board offers no crticism, but we are willing to learn

I vote for intuition first (that must have been correct) and after that it's worth a "wow"

[sispanys ria]

Rainboe, I will not comment on your aggressive attitude towards me beside I'm sincerely posting without any bad intention.

The idea is to keep flying just above stall- 108kts sounds about right! You need to keep attitude control to the end.

Flying just above the stall speed with high fpm is definitely not the best way to increase the gliding distance. Without anymore referring to the particular BA038 flight (I don't have enough experience and material to elaborate) I would still appreciate to discuss the following 3 options that have been mentioned assuming a plane looses power in similar conditions and that the crew is immediately aware of it and able to react:

1- You try to remain on the glide, meaning you have to pull on the stick which results in decaying speed and ends in a pre-stall high fpm steep descent till impact.

2- You don't pull or push on the stick and the plane will lower its nose as it will try to keep its IAS. Once you reach a reasonable flare height then pull on the stick to keep the plane level, drop the flaps and finalize the flare to arrange low IAS/low fpm impact

3- You push on the nose to accelerate the plane and then deal with a dangerous flare due to inertia, while you probably spoiled a lot of energy while changing your pitch.

I understand Rainboe would definitely go for option 1 while I would have bet for option 2 .

I would appreciate if you could elaborate on this choice and especially highlighting why option 2 wouldn't be applicable. Thank you

[overstress]

None of the above is relevant as the autopilot remained engaged, attempting to maintain the glide. Besides, as we all know, in the stall, 'pulling' on the stick makes you go down faster.

The initial aiming point was the TDZ, as the a/c was maintaining the glide. There will always be tarmac before that, had the engines done their thing 20s later they would have crunched on the solid stuff, what would that have done at 2000fpm?

[misd-agin]

sispanys ria,

You're on the right track. Slowing below L/D does not increase your gliding distance. L/D is L/D. L/D does not get better right approaching stickshaker.

While larger jets do have more inertia they are not locomotives or large ships that are relatively unmanueverable.

[snowfalcon2]

M.Mouse,

thanks for this thread's most informative and least emotional contribution.

While fully respecting the crew for their actions in a situation they had apparently never been trained for or been prepared to expect, I have one question: Assuming no change in flaps settings, just an immediate a/p disconnect and maintaining the original approach speed as the first priority, what would the simulated outcome have been? Am I correct in guessing the plane might have made the grass in a decent flare?

[M.Mouse]

I am afraid I have not tried that and could only guess so the answer is I don't know. Sorry.

[windytoo]

I have tried it but it is incredibly difficult to produce any consistent flare away from the "runway environment" due to the lack of definition in the simulator. For real, god forbid, I am sure you could achieve a better touchdown by manually flying it but only if you could reach the same impact point that they did. Any shorter and it would undoubtedly end in a worse result.

[misd-agin]

777 pilot - "you can make the runway, you just have to be quick about it. And we knew it would happen, they (BA 038 crew) didn't."

He did not mention if they changed configuration or not.

He said they were able to flare to land and barely made the runway. Made it, but barely, with a normal touchdown.

These are issues(speed control, use of A/P, configuration changes, systems operations during events like this) that the AAIB is probably investigating.

[el #]

What about an additional A/P logic that attempts to fly the longest distance in case of thrust failures like BA038.

The idea would be to take the most reasonable reaction in automatic before the pilot takes control, he/she could also elect not to, knowing what the airplane will try to do.

I understand there can be 1000 very good reasons against the above and I'm just trying to think out of the box here.

[Patuta]

Heathrow Hero Pilot Denied Job Interview