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-   -   AF 447 report out (https://www.pprune.org/rumours-news/489790-af-447-report-out.html)

DaveReidUK 25th May 2013 15:52

Sadly I remember Staines only too well, having been working for BEA at the time.

While I agree that the circumstances and sequence of events were completely different from AFR447, I suppose you could argue that what they had in common was an experienced captain who (for differing reasons) was temporarily out of the loop, two other less experienced pilots (considerably less in PI's case) and, overall, a crew who didn't understand until too late why their aircraft was behaving the way it was.

But that's about as far as you can reasonably stretch the analogy.

One other link, of course, is that the reason we know about the confusion on AFR447's flight deck stems directly from the Staines crash (and others) which led to the introduction of the CVR.

toffeez 25th May 2013 16:00

Airbus optional AoA indicator
 
Previously posted by CONF iture:

http://i35.servimg.com/u/f35/11/75/17/84/aoa_0110.gif

BARKINGMAD 25th May 2013 16:22

STAINES TRIDENT AND TODAY.
 
I thought that the control column was held/pulled fully back by PF, the captain in the G-ARPI accident. The inexperienced and not line trained P2 and P3 were inadequately placed and trained to intervene.

Yes, there was no CVR available but that accident allegedly speeded up their introduction and the speculation at the time was of a SA breakdown.

Granted at max ceiling the AoA is critical and there may be not a lot of displacement in the angle displayed between an undesirable and a normal condition, but maybe our test pilot comrades could comment on their accuracy/usefulness in heavy icing? It seems the probes have a symmetrical section, so possibly less likely to give erroneous readings as do the pitots.

I still seek opinion on their reliability, and therefore AoA readings, following ice accretion or an argument with our feathered friends.

The accidents due to static ports being taped up or otherwise obstructed may have been prevented by the presence of and competence in using AoA direct reading info.

My only current easily accessable info on this display is a page in Bulfer's "Noddys'" Guide to the 737NG and it appears to be a brilliantly useful option which has almost universally been ignored by the 'frame buyers/leasers.

Thank you for the BEA report quote, I haven't dared try to read it yet in case I retire to the darkened room and stay there in total despair..........................:(:)

DozyWannabe 25th May 2013 16:35


Originally Posted by BARKINGMAD (Post 7861850)
... the spec for the airframe was signed, (by a knowledgeable line/training pilot-ah methinks probably not!)

If you follow the Tech Log threads, you'll find out that it in fact was.

BARKINGMAD 25th May 2013 16:48

SIGN HERE PLEASE.
 
Thanks Dozy, I should have made clear I was referring to civil airframes-all makes-versus poiny military things.

Can we all assume that the purchase/lease signatories acting on behalf of Drivers, Airframe, Civilian, are fully aware of what they are specifying and have as much requisite knowledge and background as the average high-time line dog.........?

If AF was offered the option of AoA indicators and rejected them for whatever reason, doubtless the lawyers will add that to their ammunition belt.

Just a shame the pilots in 447 were not up to speed, pardon the pun, on UAS handling as seems to be the conclusion.

Shaggy Sheep Driver 25th May 2013 16:56

While I'd be the first to agree that EVERY aeroplane should have an AoA indicator (AoA is what wings and therfore flight is all about!) I doubt it would have made any difference in the case of AF447. They had ample cockpit information to fly the aeroplane, particularly attitude information, and they didn't use it.

Concorde did have AoA indicators I guess because AoA is particularly critical on a thin, narrow delta at the high end of the range.

Does / did any other airliner?

DozyWannabe 25th May 2013 16:57

@BARKINGMAD:

No probs. :ok:

I don't want to bang on too much about this - but AoA gauges were also discussed, ad infinitum, on the Tech Log threads. I'd suggest looking there.

@SSD:

Agreed - one of the more thought-provoking aspects of the Tech Log discussion was that the PF in this case seemed to be suffering a startle response so profound that he immediately started pulling up before even trying to assess the situation, thus making said assessment harder for both himself and his colleague. Given that they were unable to diagnose a stall with the warning going off, ADI indicating a nose-up trend and a rapidly unwinding altimeter - would an AoA gauge have improved things or merely heaped more data on them when they were struggling to process what they had?

Fox3WheresMyBanana 25th May 2013 19:05


AoA is particularly critical on a thin, narrow delta at the high end of the range.
It's important, but even more so at the other end, e.g. single engine heavy weight swept wing approach in the Tornado F3 - ideal AoA 16, Limit for control 17, Limit for u/c 15...no pressure!

Shaggy Sheep Driver 25th May 2013 19:36

Fox 3 that's what I meant; "at the high AOA end of the range". On Concorde, a small increase in AoA induces a big increase in drag at that high end (like on the approach). VZRC lurks! Especially if there is an engine out. Bad news near the ground.

BOAC 26th May 2013 07:59

As Dozy says, 'AoA indicator' has been done to death (no pun intended) in Tech Log. Yes, a very useful piece of kit. In my (limited) experience in partially jet-borne operations, vital, BUT it does require an understanding of how aeroplanes and wings actually work which so often seems to be missing on PPrune and particularly in the cockpit of 447, and of course, that nightmare !MONEY SPENT! on installation and training.

gazumped 3rd Jun 2013 12:13

Bubbers44
 
I did some very interesting test flying many years ago in some light twins. The reason was to explore a "deep stall" ie, after provoking a stall(@ 10,000 feet or so) wait for the nose to drop and then pull in full back stick for one second.

The results were amazing, and suffice to say, enough to gain a very healthy respect for speed control at anywhere close to the ground.

These light twins were generally very docile aircraft, PA-31, EMB110 , B200, and similar. The height loss is these deliberately provoked stalls were universally in excess of 2,500 feet. This, from aircraft that regularly lose no more that 50 to 100 feet in stall training.

I have never stalled a heavy jet at or close to its service ceiling, but I would say it is high time this was included in the standard syllabus.(of course only in the sim). I would have a guess that once "deep stalled" a A330 would require in excess of 15,000 to recover, and only then if the correct control Imputs were done.

Thoughts anyone?

DozyWannabe 3rd Jun 2013 13:27


Originally Posted by gazumped (Post 7875264)
I would have a guess that once "deep stalled" a A330 would require in excess of 15,000 to recover, and only then if the correct control Imputs were done.

Thoughts anyone?

If you have a look through the Tech Log threads, you'll see that we did some experiments in an A320 sim (didn't have access to that of an A330/340). So with that caveat, plus the fact that the sim works on extrapolated flight test data in the stall regime and a non-pilot (i.e. me) was at the controls for some scenarios - we had the aircraft recovered from a stall at FL380 within about 18,000ft using just the sidestick to recover, and about 12,000ft using the trim wheels to centre the THS plus sidestick to initiate nose-down/descent.

BOAC 3rd Jun 2013 13:48

Way back on thread xxx- I ventured my opinion that around 20k was probably the last point at which they might recover, based on nothing but a 'feeling' and a thought about the 50 degree nose-down pitch change required....................

Ye Olde Pilot 3rd Jun 2013 21:47

This is what happens when you have system managers and company SOP's in charge of flying instead of training pilots the old way. I'm sure a ten year old kid on a computer game would have spotted this problem.

The whole transcript should be drummed in to anyone who aspires to fly a commercial aircraft.

gazumped 3rd Jun 2013 22:14

Well lets do some real world estimations. Your stall recovery in a sim in a A320 lost 18000 , and you knew beforehand you were going to stall and were mentally prepared for it (probably silently went over the actions in your head before the event), confident your life and limb weren't at risk, and still lost 18000!!!

Now a dark and stormy night, UAS, unexpected autopilot kick out, startle factor, fear for your life, as your past flashes before your eyes, would have to add a50% factor to it, makes a recovery possible in say roughly 27000 feet!

This should be added to every heavy jet training syllabus immediately!

Our company made a mod to the sim cyclic after thus event, on climb out "one " IAS failed and you had to determine which was the faulty one. Then we did approach to stalls at 37000 with a full panel. I don't want to be highly critical of my own company but for heavens sake talk about underdone!!

I have voiced my opinion to anyone who will listen and just get some vague platitudes, and then the listener's eyes seem to glaze over. It seems all too hard!

There have a number of high altitude loss of control events over the years, and AF447 seems to be just another one.

HazelNuts39 4th Jun 2013 12:22


Originally Posted by gazumped
I would have a guess that once "deep stalled" a A330 would require in excess of 15,000 to recover, and only then if the correct control Imputs were done.

The correct control input is initially quite simple: full nose-down maintained until the airplane is unstalled and the stall warning stops. Then comes the tricky part - recovering from a steep dive without overspeeding and without entering a secondary stall.

A near optimal manoeuvre would have recovered the airplane within about 11000 ft to level flight at a speed close to Vmo.

gaunty 4th Jun 2013 12:38

Click, click, click. :ugh:

gazumped 4th Jun 2013 12:39

Hazelnuts
 
I don't think you could say that this crew of AF447 , were ever in danger of performing a near optimal manoeuvre.

The sim tests in a 320 mentioned earlier give 18000 as an achievable figure, my fudge factor of 50% I think would be reasonable netting a cool 27000!!

So somewhere between 11000 to 27000, I can guarantee you these numbers would be known by very very few line drivers(or senior management )

The argument for inclusion in sim cyclics can hardly be stronger.

I seem to recall a China Air B747 losing control because of an un-noticed outboard flameout, the resulting auto pilot unlock and VMC/stall/over speed was not recovered from till the aircraft broke out of cloud and became visual. The aircraft diverted to Anchorage, and was subsequently a total write-off.
This crew ad a complete panel of serviceable instruments.

It would seem the sheer lack of hand flying skills has been around for some time.

NWstu 4th Jun 2013 16:06

gazumped
 

I seem to recall a China Air B747 losing control because of an un-noticed outboard flameout, the resulting auto pilot unlock and VMC/stall/over speed was not recovered from till the aircraft broke out of cloud and became visual. The aircraft diverted to Anchorage, and was subsequently a total write-off.
This crew ad a complete panel of serviceable instruments.
Link to AAR here

Brian Abraham 4th Jun 2013 17:24


diverted to Anchorage, and was subsequently a total write-off
Landed at San Fran. Aircraft repaired and returned to service, with a little extra dihedral.


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