TIMA9X

By FDR Your posts are always a pleasure to read, I was looking forward to hearing from you and your views on this matter.

sky9Another fantastic point of view which I relate to, and certainly got me thinking!

Thanks for the input guys nice to get some positive informative points, just "great insight for guys like me."

Cheers
timA9x

captplaystation

I agree, the trim clanking round on the 737 is a valuable cue. . . . but, it didn't seem to be noticed by the Turkish crew, or indeed the Thomson crew in BOH

N2NB9H

I thought that we shouldn't make any comparison with these incidents/accidents

The Turkish auto-throttle induced accident resulted in the following Boeing guidelines for non-normal situations:
Link: Flight Crew Monitoring During Automatic Flight

It also says:
The application of these recommendations also prevents trim induced issues. AT and AP are quite interdependent systems and the second one will definitely be affected by issues related to the first one.

Keeping one system without the other can be tricky.

holteboy

Wonder if anyone has tracked down the character who climbed back up the escape chute to get his personal effects ?

OK - I'll be benevolent - shock !

BoeingMEL

..My log-book shows that it's almost 25 years since I flew a 733... but I always believed that that saw-bench stab-trim wheel spinning by my right thigh was one of the most reliable flight-status/aircraft-configuration indicators on-board.

I'm happy to join those rooting for Pete... he's a thoroughly decent and modest professional. Australia tho?... C'mon Pete..who else is going to share my CabSauv? Cheers bm

Baron rouge

In your long answer to SFLY #3038, you said:

Would you agree then, that as a crew, you deliberately chose, having noticed the reduction in airspeed, to keep the A/C on the glide slope inducing the inevitable drop on the wrong side of the drag curve, and a big big increase in drag.

You were perfectly aware that your A/C needed less drag, hence the flaps reduction, but your copilot let the speed decay to stick shaker speed, this is neither coherent nor safe for a pilot flying a then glider.

But in the end he was right as everybody walked out from that landing.

sky9

Baron rouge,

I think you are being a little unfair, the crew were placed in unfamiliar territory with only about a 5 sec window to do anything that would have allowed the aircraft to reach the runway and no help from previous experience other than the experience of knowing what happens to an aircraft with idle thrust and full flap. In my view the only thing they could have done was immediately bring the flaps up to G/A flap to reduce drag, otherwise there but by the grace of God go I.

As I wrote before the elimination of the stab trim wheel in Boeing aircraft (and the total lack of flight control feed back and throttle movement in Airbus aircraft) was a retrograde step as it makes monitoring an aircraft totally dependent on visual clues.

barit1

I've oft been known to stick my foot in my mouth - and this is no exception:

Assuming (we all know what that means) that one has a choice of speeds at which to touch down off-runway, would you not prefer to do so in a minimum energy state, rather than at Vref? In other words (to quote my father, a WWII F/I) run out of airspeed and altitude at the same time?

Granted - there is a technique to doing so, best practiced more than a few times on the aircraft in question.

Purely hypothetical, no flames please.

Baron rouge

Barit 1, You are right, this is called flare the A/C, and if done correctly you touch wheels just above stalling speed and as in the case of Ba 038 when you have full HYD power you can even use full flaps just before touching down

barit1

Of course it's called the flare. I was just being a mite academic.

And I suppose a tailstrike would be the least of your worries.

Thanks for the confirmation, anyway, BR.

MathFox

I think that finding an area that allows for a smooth shedding of landing energy also is of importance to keep damage to passengers, crew and plane down. Touching down in the safety zone of a runway, avoiding major obstacles (or picking a nice, obstacle free stretch of water, like Sully did), helps to keep injuries down.

Heidhurtin

I'm not a pilot by any stretch of the imagination (barely able to control a car ) so I'm not qualified to comment on the technical matters here. I've been in the British Army for 28 years though, and am familiar with situations which are unexpected, sudden, require an immediate decision with rapid assimilation of data, would have catastrophic consequences if made wrongly and have many dependant souls. In such circumstances a combination of training and experience kick into play very quickly, and it's this combination that gives one confidence and allows one to think outside the (SOP) box if required. I'm gratified that, in this button-pushing age, some pilots still have the "gut knowledge" to take the correct action. (I know this debate continues elsewhere and although I have an opinion, I don't really want to get involved so please be gentle).

My real point though is this - Capt B sir, if you managed to get through those 30-odd seconds without uttering a single expletive, then you are, truly, a better man than I.

Cap doffed

RatherBeFlying

Decreasing the flaps from 30 to 25 got the a/c an extra 50 m. which avoided hitting the ILS (localiser) antenna array.

There have been suggestions that go-around flaps instead of 25 could have obtained a better result and doubtless simulator trials could establish whether that would have helped or not.

In the abbreviated time available to the crew, any such results were not available.

There is a conflict between obtaining good enough and the best possible. The danger in trying to improve upon good enough in a limited information context is that you might go too far. It's well known that every decrease in flaps increases stall speed, but less well known is that flap retraction can call for lowering the nose to regain the correct speed -- the ground can get in the way of that as the experience with flapped gliders has shown.

Alaska Airlines Flight 261 is instructive in this context. The crew had regained control from loss of stabiliser control and began to vary the flaps. The initial selection of slats and flaps had fortuitously worked well, but retraction put the a/c into a degrading control situation as the already heavily stressed jackscrew gave way.

In BA's case the crew wisely restrained themselves from explorations better confined to a simulator once a good enough result had been assured.

Dave Gittins

As has been explained most precisely, eloquently and at great length by the man himself, Capt B, (try post 2964) even Boeing's best in the sim trying every possibility couldn't improve on the distance that 30 reduced to 25 gave.

Baron rouge

Dear DAVE Gittings

Do you really believe that ?

Do you think an A/C flying at VSS, on the wrong side of the drag curve, could land as far as one flying at VREF and using the surplus energy to flare and make a controled landing?

You have a poor opinion about our American friends.

Dont Hang Up

Looks like we're going round the argument yet again.

Isn't the point that they were already on the back of the drag curve by the time it became clear they were landing with little or no power? Trying to retrieve Vref from there would surely result in the ground getting in the way.

Theoretical conjecture about what may have been achieved by a crew in full readiness for double engine failure at 600ft seems pointless.

infrequentflyer789

So, do you believe that Capt B lied on this forum - because that is what you seem to be implying ?

The results might be counterintuitive, and there might be interesting reasons why no one got further, but to simply deny that the results were as stated (because you find them odd) is a serious accusation.

TIMA9X

By Don't Hang Up I have to agree!

The report is out, this thread has been over and over this sort of stuff to the point it just does not matter anymore, or just plain meaningless!

There have been too many current pilots with a lot of combined commercial flying hours flying the heavies who have praised the crew for their actions. If Boeing could not simulate a better result then why are people at this point of the thread still banging on about the same old stuff!

The 777 is roughly 270 tons and I am convinced the crew did the right thing by raising the flaps back to 25 (pretty quick thinking don't you think considering the time they had) probably a major factor that got the AC over the fence and those ILS antennas etc. This crew did know the feel of 777 when it goes against what it is usually supposed to be doing, and got the thing down with no power and with no deaths. Can't we give them some credit for this instead of returning the thread to all the what if's! IT'S LIKE SAYING THE CREW DID NOT KNOW THE DIABOLICAL SITUATION THEY WERE IN ( A FEW SECONDS TO FIGURE IT ALL OUT) ON APPROACH TO LHR R27L THEIR HOME BASE!

Blythy puts it well. In this case it is really that simple!

EBMissfit

Lets put this one to bed - The decision to go to flaps 25 was the right one - and got them further than staying at 30 would have done. Pete himself said had he realised earlier that the power wasn't coming back he would have gone earlier and possibly to 20. What SFLY & others are arguing and what PB would probably agree with is that if at the very moment the second engine rolled back, they had configured to 20 and pitced for best glide, they may have got further, possibly even to the rwy. What they are ignoring is that this could only happen if you were expecting that. People also keep talking as if they "lost" the engines. The engines were producing thrust above flight idle the whole way - there would be none of the usual indications of an engine out - no bells, whisltes, flashing lights screaming at you that you had an engine out situation. As it is in very short order (within 30 seconds of the first rollback) they had identified that something was wrong at they were down on thrust. Within 30 seconds of that they had reconfigured the plane at got it as for as possible in that timeframe.

Baron rouge

We have yet to read any official information about Boeing simulator trials on this case, but my little finger tells me that certain Airline 777 captains, flying speed instead of glide slope managed to grease it just on the runway or slightly before with a much better controlled rate of descent.

Nobody is lying here, maybe some information is a tad incomplete.

Great job from the Captain thinking about reducing the flaps setting, but is it wrong to question why, as aware as he was, thirty seconds before touch down, of decaying speed, why he elected to let his copilot fly the glide slope to VSS.