AF447 wreckage found

[ChristiaanJ]

Originally Posted by flydive1

The wright flyer used a side stick

Thanks, nice one!

[DozyWannabe]

Originally Posted by Welsh Wingman

...I interpreted his comparison between the crashes as limited to the similarities between the instant discomfort of the PF upon losing his automation. I don't think that was a happy cockpit from the A/P disconnect, and the roll oscillations weren't long in coming....

The Air Inter captain never entirely lost his automation, just his pre-programmed approach. He never got as far as having to manually control the aircraft, instead following the radar vectors and initiating descent via FMC input.

DozyWannabe - but you raise a point that TJHarwood appears to have overlooked i.e. PNF "nagging". Wasn't the PNF in 1992 concerned about the PF's positional shortcomings (sadly horizontal, not vertical) in much the same way as the AF447 PNF was concerned about the PF's inputs and the climb? Good point re: disconnect between pilots on both occasions.

Thanks! So - if I recall correctly - yes, the Captain started to say something to the effect of the altitude or V/S not looking right, and in an unfortunate coincidence, at the exact same time the F/O interjected to point out that the display had them to the left of the airfield (which was due to ATC turning them onto final prematurely), which then preoccupied both pilots (in much the same way that an unfortunately-timed radio transmission distracted the Kegworth Captain as he began to re-evaluate the symptoms).

And whatever one think about an AoA indicator or BUSS as an option, I think we can all agree that a GPWS should never be optional (whatever SNCF's TGV competition).

Of course, with 20/20 hindsight!

Human factors, and that must focus on the interface and training. Automation, properly used i.e. "airmanship plus".

No argument from me there!

@CJ : I think the first modern sidestick came with the Mercury project at NASA.

[Welsh Wingman]

DozyWannabe

I haven't been following this thread from the beginning, so not sure from where the "story" emerged that B777 yokes was purely down to United line pilots. It most decidedly did not, and there was widespread consultation with Boeing's 747 Classic customers (the target market for the B777, in competition with the A330/A340). My 747 Classic F/Os, that are still flying, are predominantly on B777s.


777-Yoke Vs. Sidestick


With all due respect, and I really value your contribution to this thread, and which is always insightful, I think a better analogy would be the migration from horse and cart to the motorcar - whether reins or wheels, the retention in front of you over which you clearly control (whether horse or machine).


We all know that "feedback" to yokes is artificial, and has been for decades, but a yoke emphasizes control (pleases Joe Sutter!).

The argument, for those that are not "fans", is that the SS regime inadvertently disconnects the PF from the aircraft and (at least without interconnectivity to the other SS and with artificial feedback through the SS to the PNF) from the other pilot - it is a system operator tool, rather than a pilot control tool, if I may put the argument in those terms.

I am undecided because overall Airbus are excellent aircraft with an excellent safety record (particularly if you remove the "human interface" crashes from their list of casualties, and Boeing have had more than a few LOCs). I also take your point that the SS came out of the USA through the F-16.


None of this would of course matter to this thread, if the pilots were at one with the A330 comprising AF447. But this is currently very much a point of contention...

[ChristiaanJ]

WW,
Thanks for the link.

[Mr Optimistic]

The stick v yoke argument is irrelevant to this isn't it ? Ditto analogue v digital displays. The logic that increased automation has reduced the necessary total human capacity on the flight deck would seem more fundamental (the arithmetic supporting the argument that any given level of safety can be achieved with fewer people eg no FE owing to the automatics). Fine when the automatics are present and correct, not so solid in an accident sequence.

[infrequentflyer789]

Originally Posted by DozyWannabe

"When we went from horse-drawn carts to motor vehicles, did we attach ropes to the front axles and steer with that (because after all, that's what people are used to), or did we design something more appropriate for the technology?"

Careful, the early cars were actually steered with tillers - just as people were used to in boats. Steering wheels came later, but again the pre-existing nautical usage is not hard to spot...

[AlphaZuluRomeo]

Originally Posted by infrequentflyer789

Did I win ?

Nice
But, as you noted, that's an aircraft. I do not know of any manufacturer which have already made a better one (i.e. not prone to human errors, nor physics laws)

[Welsh Wingman]

CJ

A complete tangent, for which I apologise in advance to all others, but what did Andre Turcat make of a SS on the test SST?

We ended-up with ram's horn yoke, FBW and elevons with artificial feel.

Was there any significance to the final choice, given that aircraft type went under rigorous testing unheard of today (sadly to post-oil crisis commercial disaster, compare with hurried into service DC10)?

[ChristiaanJ]

Originally Posted by Welsh Wingman

A complete tangent, for which I apologise in advance to all others, but what did Andre Turcat make of a SS on the test SST?

I'm not even sure Turcat himself flew F-WTSB with the sidestick.
But the test flight reports were positive (IIRC, will have to look through the report again), which says a lot, considering the general praise of other pilots about the manual handling of the aircraft with the conventional 'ramshorn' controls.

The side-stick on F-WTSB was never really intended for use on Concorde. After the certification flight tests, F-WTSB was used for several other 'non-type-related' tests, and the side-stick tests were part of that, and indeed led to the A320 story.

[Welsh Wingman]

Mr Optimistic

It has only become "SS v yoke", which is somewhat of a misnomer, because the AB implementation of the former does not mirror the traditional characteristics of the latter and the flight crew never diagnosed the stall.

The human factors/CRM/cockpit discipline issues that arise out of the AF447 tragedy, as regards the SS, are the absence of artificial feedback (to the PF and through interconnectivity to the PNF) and apply equally to the throttle feedback.

Enough to fill in the missing pieces of the jigsaw for the PNF, if only enough to brief the returning CDB to get him over the line....?

Diagnose the stall and get to work on ND and the THS "problem", as per the related thread on AF447, although it feels somewhat esoteric and academic in the context of a flight crew that never diagnosed the stall. But an interesting post by Owain Glyndwr on that thread, for those of you aerodynamically inclined......

[Mr Optimistic]

WW, thanks, yes appreciate that many things didn't help and that such help shouldn't really have been needed. A bit surprised (given the significance of the Capt's absence) that the more general question over whether two is enough isn't on the table. Noted that another company operates dual Capt/FO type arrangements - this sounds comforting to me as Pax.

[Welsh Wingman]

CJ

Interesting. I can see a transition from yoke to SS as evolutionary, with the right training, but the loss of artificial feedback (including interconnectivity to the PNF, and also the throttles) makes it revolutionary and makes me, as British, about as enthusiastic as Margaret Thatcher having to go to the bicentennial of the storming of the Bastille!

Remove the flight engineer (the one flight deck officer devoted to aircraft systems), insufficient training for high altitude (including emergency), limit by-hand flying, lack of urgency about replacing a part critical to the aircraft system (pitot tube) and then give the pilots no blatant mechanical feedback through the SS and throttle at the moment of maximum sensory overload in the middle of the night during a reinforced oceanic cruise (sadly without a visual horizon, and sufficient to ignore a stall alarm albeit complicated by the 60knt/AoA design floor). I am not saying the flight crew should not have done better, because my thoughts can be deduced from my previous posts, but to keep chipping away at the margins...?

Would you deliberately design this from the outset, irrespective of the CRM issues on this flightdeck? Lyman (or whatever alias!) would not, and quite a few of you might find yourself uncomfortably in agreement with him over this.......

[DozyWannabe]

Originally Posted by Welsh Wingman

The human factors/CRM/cockpit discipline issues that arise out of the AF447 tragedy, as regards the SS, are the absence of artificial feedback (to the PF and through interconnectivity to the PNF) and apply equally to the throttle feedback.

Enough to fill in the missing pieces of the jigsaw for the PNF, if only enough to brief the returning CDB to get him over the line....?

Again, a valid opinion - but certainly not an incontrovertible fact based on the evidence available. We've had an A330 successfully deadsticked into the Azores, an A320 very famously deadsticked into a near perfect landing on water, and conversely we've also had several yoke-equipped aircraft (B727, HS Trident, B757) go into a full stall and crash despite all manner of stick-shakers, stick-pushers and so on giving tactile feedback to the crew (which at least one crew mistook for Mach buffet). It was discussed at length in both the Tech Log thread and this one if you want to check it out.

The upshot of this admittedly anecdotal evidence is that the tactile feedback channel may not be the panacea for communicating aircraft behaviour to pilots that the pro-feedback brigade seem to think it is.

@WW (above, regarding "would you design...") - As I said in greater detail in an earlier post, Gordon Corps certainly didn't mind - ultimately he was the senior engineering pilot who signed the design off, and he was nothing if not a first-rate, safety-conscious pilot of the old school. The design itself was specified with input from pilots of all levels, from the line, through engineering pilots and test pilots.

@CJ (below) - when would it activate? I could see it being annoying if it was on all the time - perhaps when the trim passes a certain threshold which varies with altitude and AoA?

[ChristiaanJ]

Originally Posted by DozyWannabe

The upshot of this admittedly anecdotal evidence is that the tactile feedback channel may not be the panacea for communicating aircraft behaviour to pilots that the pro-feedback brigade seem to think it is.

Yes, no.....
Personally, I'm still wondering about the absence of the "bicycle bell" on the THS trim wheel.
Not tactile feedback, of course, but still feedback.

[Welsh Wingman]

Mr Optimistic

Now that is optimistic!

A fully reinforced (i.e. duplicated) flight crew would be preferable, ceteris paribus, but there are the same cost issues that ended the flight engineer (who would also have to be reinforced). Even a relief CDB and F/O is not the end of it, because you have the Van Zanten/Meurs CRM issue at the other end of the spectrum to AF447.

Takata set out the AF procedures at the time of AF447, and how the junior F/O in the RHS came to automatically become PIC. Interesting, and thankfully no more....

DozyWannabe

There will be nothing "incontrovertible" about AF447! Look at the number of pages on this secondary thread....

I believe, and have strong views on the point, that the need after Stony Point was to ram into every pilot's head that, before discounting a stick shaker (yoke or SS), that an uncorrected stall = death. End of. Be absolutely certain, as you watch your VSI plummet.

A SS with the same function is not a philosophical problem for me, even if it is to others, but a deadstick makes me nervous. As you state, you can land an A330 "glider" with a deadstick and airmanship. It is the additional scanning at the moment of maximum stress in an emergency that is unwelcome, when feedback and interconnectivity aid cockpit discipline in a cockpit that needs assistance.

If Boeing and Airbus, in unison (even if they preferred feedback yokes and feedback SSs respectively), had addressed stall issues, I would like to think that 9L/CJC 3407 could have been avoided (let alone AF447).

I have some difficulty with any argument from anybody on this forum that, if the LHS SS had been moving in tandem with the RHS SS as a result of the PF's inputs, it would have made no difference to what the PNF would have said and done (particularly in the initial critical pre-stall phase). PNF was "nagging" PF, without such feedback assistance, instead of calling the UAS drill.....

P.s. re: "design" - I mean the totality of that paragraph. What Gordon "signed off" is not necessarily what he would have preferred, and he could not possibly have envisaged the industry changes over several decades on the human interface issues that have arisen.
P.p.s. I would almost go so far as to secondary alarm the THS trim wheel whenever you depart from normal law in an AB, to keep the flight crew cognisant of the manual trim issues.

[Welsh Wingman]

CJ

Please don't get me started on the THS trim wheel tonight, or I will never get to bed..........feedback, yes........but leave that one for another day.

[Mr Optimistic]

But didn't the PNF take control only to have it snatched back, and this with the Captn present ?

[Lyman]

The direct cause of 447's crash will not be "direct". To get to a single vector is impossible.

A starting point would be the untoward (and shamefully anticipated) dump of the a/c control into the hands of the PF. It had happened, though likely not ever in such piss poor conditions. This makes the foot dragging inexcusable.

There are no explanations, only excuses. Because all the precautions, all the preventions, were inadequate. How about that, then? One cannot focus on a single iteration; they were without exception, re-iterative.

In a perfect World? OK. PARK IT. FIX IT. Won't happen. I cannot say it cannot, but it won't.

That is why TRAINING is such a whine. And since it is a whine, it is dishonest, and arguably criminal. It is also self incriminating, the Pilot group does not self train.

Airframe?

The two or three glaring problems won't be fixed, too expensive.

What was known, and when did it become so? Ask that question of Socrates, or some modern day Solomon. It will be ignored.

PITOT. STALLWARN. THS. UAS Procedure. (This last, alone, food for an action at LAW that would cripple the players, and indict the Authority.)

When "corrections" can be applied before the engines have cooled, does one not think that the problem was a priori?

[DozyWannabe]

Originally Posted by Mr Optimistic

But didn't the PNF take control only to have it snatched back, and this with the Captn present ?

Yes he did, but it was approximately 5 seconds before the Captain arrived, the PF took it back after less than 2 seconds, the PNF presumably turns to talk to the captain as he comes through the door and in the intervening time (approx 2 seconds after the Captain enters the flight deck - so the Captain should have heard it, albeit briefly) the stall warning stops.

I've not put this together before, so it raises some very interesting points and questions.

• At the start of the sequence, as autoflight trips out, the PF makes the callout "J’ai les commandes" ("I have the controls").
• The PNF was preoccupied with the return of the Captain (and unless I'm reading it wrong, increasingly unhappy with how the aircraft seems to be being handled) before finally deciding to take the controls himself, just before the Captain arrives. He says "Commande à gauche" ("Controls on the left"), takes priority and makes a small nose-down and left correction.
• Now I thought that statement was ambiguous to start with, and was roundly told that it meant he was making a left-stick input. Now I've seen he takes control, makes the callout *and* makes that input at the same time, I'm unsure again.
• Was he aware that the PF had taken back the controls without announcing it? (interconnection aside, that's a flagrant breach of procedure on the part of the PF *unless* he interpreted the PNF's "Commande à gauche" callout as an order to apply left stick and as far as he's concerned still has control. Can anyone clarify what the correct callouts should have been?)
• The stall warning stops just after the captain arrives, and just after the PNF took the controls and made a couple of small corrections (which were correct, but nowhere near enough). Does he think his corrections have solved the problem?
• Either way, that's an unfortunate set of time-critical coincidences.
• Five seconds after that, the PF makes his "crazy speed" remarks and starts to throw the speedbrakes out, prompting an emphatic warning from the PNF not to do so. How much more pressure and cognitive load can one guy take?

Hmmm...

@WW - I think the lack of properly defined command gradient is a much bigger problem in the case of this incident than the feedback issue. I say again - same thing has happened plenty of times with interconnected yokes and it made no difference to the outcome.

[Lyman]

Interconnected ss may have made it worse, (in the moment, and not anent outcome). Mutiny was alive, and there was never evidence of a quiescent Flight Deck, only harping, stubbornness and questions asked rhetorically instead of "teamed". Sad. I think the Captain's call and arrival hurt the situation, did not help. It solidified the stubbornness, instead of loosening it. It gave a third leg to the stool of confusion.