Thanks, glad to hear it was by his own choice.

The report mentions that the FO initially believed he had disconnected the AP and that he subsequently omitted to do so until the stick shaker activates 450 ft lower. My understanding is that nobody knew who was flying the aircraft during this 450 ft descent.

A very interesting CRM situation totally unexplored by the report. Why discussing it should be considered as attacking the crew?

Having listened to that ATC transmission and watched the interview with the remarkably humble Peter Burkill on the BBC website, I just wanted to say that I really do take my hat off to all you guys who work in professional aviation, including ATCOs as well as pilots. The skill and dedication, evident here in what was obviously a distressing event for all, is simply second-to-none. :D

As for S.F.L.Y, I suggest you take step back and look at the 'bigger picture' (if you are capable of such lateral thinking). And listen to that recording again and again until you have finally digested how quickly things unfolded. You were presumably "disappointed" too by the fact he got the flight number wrong. The mind boggles. :ugh:

Having no experience on this type or indeed any FBW aircraft I have no idea of the relative "feel" of the controls A/P engaged or disengaged.
Given the situation they found themselves in , I don't find it too surprising that they could have missed this, assuming the control feel is similar.
On something like a B737 it would be fairly self evident , as the controls (even in CWS) do not feel the same, and anyhow the aircraft would have wandered off on a tangent, but with FBW, gust alleviation, and all these other boxes of tricks between you & the hardware ? perhaps someone experienced on type can tell us.

Quote: ""if it had come down moments earlier, it would have landed on buildings ect " why do they do this, whats the point""

To sensationalise a rather mundane answer to a serious problem I should imagine.

Quote SFLY- "It clearly says in black and white that the FO omitted to disconnect the AP, which is quite different from a conscious decision to keep it engaged"

Faced with 700 feet of air before bellyflopping onto houses below, it may well be easy to "overlook" disconnecting the autopilot if one is fighting to keep the aircraft airbourne.

Anyone with the engineering data that backs up the tube trimming exercise? Because I see it as a thermal solution to a mechanical problem. When the oil's cold, (let-down, cold-soaked cruise,) it will melt icebergs ahead of the Titanic?

The problem is defined as Ice related; no new research is available to mitigate what is demonstrably a potentially life threatening occurrence.

Of course the tubes are the bottleneck, they still are. An elegant "solution" to be sure, but for which problem?

Why not a wet particle separator upstream the "heater"? :ugh:

bear

S.F.L.Y

Ok.....NOTED.

Transcripts of the Colgan cockpit recordings were made available, word for word.

Well, the final report is now 'official' and we can all now start to pick it apart if we choose. I stated very early on in this thread that I didn't like the idea of the crew electing to raise the flaps a notch. This could ONLY cause a descent rate greater than what existed at the time. Raising the flaps that close to the ground is a 'no-no' in my book. I've been in an airplane when the flaps were raised by mistake, and believe me that "sinking" feeling is one you do NOT want to feel in an airplane close to the ground. And we were at take-off power. We did not hit the ground, but the 'pucker' factor was something else !!

I feel that while they might not have made the runway, the descent rate would have been less and consequently, the damge less, had they left the flaps alone. However, being as how no one was injured in this accident, there really isn't much more we can argue about now except if one is ever faced with this situation again in the future, I hope they will NOT raise the flaps to try and gain a little extra distance.

OK.....let the 'flames' begin.

What's?
 

SFLY

I've followed your comments on a number of threads and all I can ask is; 'what's your problem with BA?'

I'm not a pilot, my expertise is communication and the subtext of all that you write leads me to the conclusion that you have personal issues with BA.

Did they turn you down? If so, let it go.

StainesFS post 2869

I agree with your sentiments about gongs and honours for doing one's job but I seem to remember that years ago when a BOAC 707 crashed at LHR shortly after t/o the stewardess was awarded a posthumous George Medal and John Davies was given an MBE for his air traffic controlling of the situation.

DCATE

I learned never to raise flap on G/A unitl Pos ROC and then slowly. I learned not to chase Glideslope without engines as well. But I've never flown anything bigger than my house. I too posted that sink would follow a retracting flap. No flames from me. However, I also learned not to criticise success. This whole deal is mx.

bear

DC-ATE, in the report they seem to think that had the flaps remained @ 30 they would have landed 50m sooner, and ploughed through various antennae.
The effect of this has not been calculated, but it is being assumed substantial damage may have been caused to the airframe.
So, like so many aspects of this approach, including the "fixation" of some that they reduced below best L/D, missed the autopilot etc etc, generally held wisdom was not recognised/ acted upon, but the final conclusion ? Result ! :ok: So WTH ?

DC-ATE

Quoting from the report:
The report also states that if they would have touched down with flaps 30 they would probably have taken out the ILS antenna with a high chance of heavier damage.

Don't you think you have to take into account the fact that flaps were reduced only from 30 deg to 25 deg? I guess this would mainly reduce drag while marginally reducing lift. It would of course be a different story if you would reduce flaps from for example flaps 15 to flaps 10.

DC-ATE,
Which aircraft and what do you mean by 'raised'?
Not the conclusion of the accident report.

On the big jets I've flown the go-around procedure is:
Max thrust
Flap 20 (thats TWO notches up from the land setting of 30 and is executed IMMEDIATELY)

Never noticed any 'sink'.

I have no issues with BA. None. OK, I'll admit, I don't care for the F/A's red, white and blue striped shirts. Minor point.

I don't agree with S.F.L.Y.'s focu on 'omission'. If you plan to fly a visual, hand flown, approach, and get distracted and don't turn the A/P off, your actions fit the definition of an omission. Big deal.

As a pilot I'm very disappointed the pilot corps will learn nothing from this report regarding maintaining Vref, or allowing the a/c, IMO, to prematurely slow to achieve the best glide performance.

Also, no explanation about the value of retracting flaps at Vref, as opposed to a much lower speed, and the performance increase(?) that might be achieved.

And the pushover at 200'? What impact did that have on the a/c's sinkrate? Would the next crew that this happens to be better off staying at stickshaker or pushing over at 200' to stop the stickshaker? How much altitude does an airliner need to achieve an increase in airspeed to offset the increased sinkrate?

Yes, the crew was in a desperate situation. That doesn't mean that we shouldn't research their actions, granting them some benefit of doubt due to the nature of the event, to figure out what the appropriate actions are.

Our profession demands a critical analysis of events to help generate improved outcomes in the future.

Basil,

Two different scenarios -

On a g/a, as you stated, you're increasing thrust. At the same time you are also rotating to an increased pitch attitude. A sink is never noticed.

The other situation is with fixed power, pitch, at very low airspeed, and then retracting flaps.

i have followed this thread for most of the 2 years but sorry i cannot remember if re-flying the same flight in the sim but without raising the flaps a notch got them on the runway ok?

did it or did it not please?

thanks

Misd

From what I have followed that seems to be the case...a bit of 'there but for the grace...' followed by, 'how can we learn from this and improve?'.

As far as I have seen SLFY's comments were more postural, i.e. 'I would have done xyz, aren't I so clever'. Perhaps not his/her intentions but if so some classes in humility wouldn't go amiss.

I cannot help feeling that the greatest omission from the accident report was the failure to thank our contributers for their selfless and assiduous devotion to providing the investigators with the detailed advice borne of PPRuNe experience without which the document would doubtless be short and lacking in substance, which oversight will, I am sure, be corrected in any future publication of the report.

Should have put this in: ;)

From the report:
and:

It was a DC-6 and by 'raised' I mean retracted. They were at the Take-off setting and the FE retracted the flaps instead of the gear. [You'd have to know the layout and handles on the DC-6/7 to understand.]

I know that was not a 'conclusion' of the report; only MY conclusion.

I also understand the Go-Around Procedure. I guess I didn't make it clear that the incident I was talking about was a Take-off one. Sorry.

Check post 2889. I think that answers your question.

DC-ATE,
Thanks for the clarification.

I have to say, on the day, I'm not sure if I'd have thought of reducing the flaps a notch.
Has anyone tried straight up to 20 in the sim?

yes thanks,
i must have been typing my post as he typed his lol

i also have now managed to get the aaib report open...

i think the commander here did exactly what he felt was 'right' in his
gut feeling from his flying skills...

had he not raised the flaps he was only a breath away from likely hitting the fence and deffo the app/lights,
better he got well over it and onto the grass as they did...

We can all debate what they could or should have done, however the fact remains that they had less than a minute from identifying the problem to touching down.

While there could be good reason to go through their actions to learn for the future, nothing should be thrown at the crew for what they did or didn't do in the circumstances. They were in a situation that was outside any training scenario and unable to draw on experience.
All the POB's walked away apart from the unfortunate individual who broke his leg.

The Evidence!
 

captainplaystation
 

Well if you for some reason are trying to manhandle the controls on a triple with the A/P in you'd certainly notice, in the same way as if you tried to manhandle a 747 with the A/P in ( the 777 I fly doesn't have CWS, is it even an opton?). In my experience you only really notice the fact that the 777 is FBW if you get close to the edge of the envelope ( in the sim I hasten to add), when the various protection features start to kick in. Otherwise it behaves and feels like a conventional aircraft...then again of course it does, it's a Boeing :ok:

I cannot help feeling that the greatest omission from the accident report was the failure to thank our contributers for their selfless and assiduous devotion to providing the investigators with the detailed advice borne of PPRuNe experience without which the document would doubtless be short and lacking in substance, which oversight will, I am sure, be corrected in any future publication of the report.

Nice one Basil!

Gentlemen:

Can someone give me an idea of the inside diameters of the fuel piping in question here? Having read the entire thread as well as the accident report, I don't see where it's mentioned (though I'm ill at the moment and may have missed it).

DC-ATE,

on a MD-11 for example, if you are on a 2 Engine approach and loose a second engine on short final, one of the Memory Items is to raise the flaps from 35 to 28. In my experience, changing the flaps from a intermediate approach setting to the final landing flaps, has more to do with stabilizing speed and power by increasing drag, whereas lift changes not that much.

So IMHO the BA did absolutely the right thing by raising the flaps one notch. Lift (and induced drag) would have changed relatively little - rather the parasite drag reduced.

The crew were being faced with something they were not really trained or prepared for - especially at the end of a tiring long haul flight. Everybody walked away. I have the deepest respect for the BA crew, ATC and the rescue services. :ok:

BT

The lift drag benefit can be examined by checking stall speeds. On every airliner I've checked(6 types), the first notch of flaps reduces stall speed by 50-60%.

Obviously the greater the deflection the more drag vs lift is created.

Any old school fighter pilot can tell you about the value of leading edge devices. "Hard wing" wasn't your friend in a turning(ie high AOA) fight.

You must have read Boyd.

DERG,

That report is not a very good summary, and certainly even ignores to main report's glossing over of the actual water content issue.

.

post 2898 Basil asked about retracting flaps straight to Flaps 20.

Basil,

Vref 135 from the 777 performance pages is for a 440,000 lbs a/c(I don't recall BA 038's weight).

Stall speeds at 440K -
Flaps 30 108
Flaps 25 110
Flaps 20 115

The flap retraction was done 115-118 kts(I've seen/recall different numbers). If the 777 would allow it there's a chance that a retraction to Flaps 20 at those speeds could have triggered a stall. I have to believe, based on Vso multipliers, that the AOA would have been mucher and I'm guessing it would outweight any configuration drag reduction.

I'd believe that an immediate retraction to Flaps 20 at Vref might be the best plan. Sadly, the AAIB report doesn't give the next guys any knowledge.

How quickly can guys be expected to react? With training and awareness it could be done fairly quickly. How quick does a trained pilot apply rudder with an engine failure? ;)

For non pilots the difference for most Boeing a/c(that I know of) and I'm assuming Airbus' Flaps 2 is that the leading edge slats are in the mid, or takeoff, configuration. Most single engine configurations are based on mid/takeoff slats to reduce the drag associated with greater flap extensions.

My previous post explained how the largest stall speed reduction occurs in the first flap position(Flaps 1, Flaps 2, Slats EXT, etc). The last flap settings are just the opposite, mostly drag, with little stall speed reduction.

That is also why, as Basil mentioned, Flaps 20 is an important step in reducing drag, with a relatively small stall speed increase, to allow the a/c to accelerate rapidly during a go-around.

"You must have read Boyd." - bearfoil

Ah, brings a smile to my face. Learned his concepts, didn't all G pullers, before I read his book.

I love telling Marines that I have great respect for their branch of the service, especially since they so willing put a statue of a USAF fighter pilot in front of their leadership school. "B.S.!" is often the internal, and sometimes external, reaction.

Then they research it.:ok:

This is certainly why Boeing issued recommendations on monitoring automated approaches which insists on mandatory manual override as soon as an automatism default is identified.

Retracting flaps from 30 to 25 improves the aircraft L/D "global" configuration, but you still need to fly the right speed to get the best of this new configuration. Flying best L/D speed at flaps 30 will take you further than flying minimum speed with flaps 25.

It's exactly like on a go-around: retracting flaps is improving the aircraft global aircraft config but you still need to fly the right speed to get the best GA performances.

In this particular case the captain's decision to retract flaps reduced the poor gliding performances resulting from flying at minimum speed.

The report clearly demonstrate that it was better than doing nothing, but it sadly fails to show what would have been the benefits of controlling the airspeed.

interim measures from the report
 

Safety Recommendation 2008-047
It is recommended that the Federal Aviation Administration and the European Aviation Safety Agency, in conjunction with Boeing and Rolls‑Royce, introduce interim measures for the Boeing 777, powered by Trent 800 engines, to reduce the risk of ice formed from water in aviation turbine fuel causing a restriction in the fuel feed system.

it goes onto say...

In addition, an engine response non-normal procedure was added to provide a procedure should the engine fail to respond to a thrust application.
The procedure called for the thrust levers to be set to idle for 30 seconds,
after which each engine thrust lever is moved to max thrust to ensure the restriction has cleared.

oh....
30 seconds....? erm like you have 30 seconds to wait when your are 450' AGL
at 108 kts and both engines no longer have any ooomph in them and the staff car park badges in the windscreens are easy to read hmmmm...