rudderrudderrat

Hi DozyWannabe,
If you read the cvr transcript, both crew knew they were close to the stall.
Air Florida Flight 90 - Wikipedia, the free encyclopedia
“16:00:45 CAM-1 Forward, forward, easy. We only want five hundred.
16:00:48 CAM-1 Come on forward....forward, just barely climb.
16:00:59 CAM-1 Stalling, we're falling!
16:01:00 CAM-2 This is it. We're going down, Larry....
16:01:01 CAM-1 I know it!”

Birgenair Flight 301 - Wikipedia, the free encyclopedia
“The co-pilot and relief pilot both seemed to recognize the approaching stall and tried to tell the captain, but did not intervene directly, possibly out of deference to the captain's age and experience.”

That's a CRM problem. The other pilots recognised the approach to the stall.

Lyman

Reliability and performance are not the same thing. No one expects any system to actually cause a problem. The key is how is the performance, when there is a problem.

Two different things. When in a bad deal, what is the performance expectation?

To say that one system is not compromised in its design consideration because a separate system has been present in a fatal, is frankly preposterous. In the vast majority of cases, controls are not an issue. Can controls become an issue? Yes, I would say.

"Climb, then" "But I have been pulling for some time". Right. For some length of time, unknown to the other two crew, PF was inputting up elevators.

Can they have their time back? Request a do-over? What could have been the solution had the PF's yoke been in his lap, visible immediately at any given time?

Rest

DozyWannabe

It's been a while since I read about Palm 90, but I'm pretty sure that F/O Pettit knew they were stalling from reading the ASI, and that the Birgenair F/Os were using a combination of the ASI (which was working on the F/O's side) and ADI (the other F/O in the jumpseat calls "ADI!" out several times during the sequence). Neither made any reference to yoke position.

I know they were aware they were close to the stall. The point I was making was that even with the yoke telling them that their respective PFs were pulling into the stall, they either did not see it, or saw it and didn't do anything about it.

Lyman

As non-flying pilots, their duty is to notice attitude, not the controls that produced it. "Yoke,Yoke"....... That makes them an instructor, and is not in the quiver of a highly charged cockpit. Even in emergency, habit and tradition.

"not acting" and "acting" are on two sides of a VERY thick coin.

Case in point: 447 PNF, apparently aware, and 'irritated' does not say, "Use your Stick, Push Nose down." He points to VS, and, due protocol, waits for the correction. None is forthcoming, yet he persists, unto STALL, apparently. That part of Training may need a looksee.

Lonewolf_50

Lyman, I think you are stretching a bit too far there.

Look at the nose pitch behavior: it appears that the crew on the flight deck did not correct the nose attitude, nor maintain assigned altitude, within normal parameters during the early course of the malfunction, before it became something worse. It began as a comparatively mundane malfunction of a system known in the past to have some vulnerabilities. It does not appear that the malfunction they were faced with was novel, nor a "first time in class" malfunction.

Given that with similar malfunctions, most crews in 30+ similar events, who dealt with attitude and altitude excursions of varying magnitude ...

1. got their planes sorted out
2. remained flying
3. remained unstalled
4. prevented a malfunction from becoming an emergency.

then this crew's inability to do so stands out.

I do not wish to disrespect the dead, but I think that, with some of the info available to us via released CVR extracts, the crew has at least some responsibility, even if a BEA conclusion is reached that training, command decisions by the captain, documentation, systemic problems at Air France, probe replacement schedules, et cetera, are major contributing factors.

That "zoom climb" is to me doubly inexplicable, given that the crew were very aware of their altitude limitations for that sector of the route. Their discussion was recorded, to the effect that actual versus forecast temps at altitude did not permit a climb to a higher altitude that they had planned for (or left as an option) before takeoff.

The Airspeed was unreliable, but Altitude was not.

I cannot think of a professional airline pilot who considers a 1000 or 2000 foot altitude deviation (no less a 3000 foot deviation) as something other than very serious, and in need of immediate correction unless something else very untoward is also occurring at the same time.

Lonewolf_50

Respectfully, no.

In multiplace aircraft, when the other guy isn't doing great at flying, you do indeed resort to "instructor" type techniques and behaviors in order to get him back into the ball game. In some cases, you have to take the controls, but more often it is simpler to talk him back into the game.

"Lower your nose ...
Roll left ...
Ball's out to right, step on it ...
Add power...
We are sinking -- POWER POWER POWER! ...
The Gear's UP! Wave OFF! (Go Around!)"

All of these are solid actions / calls that in some situations must be initiatied by a good co-pilot (PNF) that are also "instructor" actions/calls.

The two roles overlap; they are not mutually exclusive.

Lyman

I make no moral judgment as to these two accidents, and you are correct. BUT, going from the evidence, can you say some political reluctance was not in play? You quote proper procedures, certainly. In these tragic accidents, I believe your "best practice" was not folowed, as it should have been. Do you see these as "best practice," then? It is occasionally extremely difficult to act without "equality" in the cockpit, that is my point.

As to 447, "Responsible" remains to be decided, and since it is in Court, some percentage value will be apportioned to whomever the principals are determined to be. If crew were briefed, officially, to ignore STALLWARN, where is their culpability? So that means that up til three seconds after a/p handoff, the pilots were totally on the hook. The first STALL,STALL is intriguing, and we do not know its genesis. PF did not "TOGA/15 degrees at this point, and did later, so to me, that indicates the first warnng was ignored. If PNF was concerned about something "What was that?" we do not know what it was.

fifty four seconds total of STALLWARN, and not a word......do you think that odd, Lonewolf?

[B]@Lonewolf...."That "zoom climb" is to me doubly inexplicable, given that the crew were very aware of their altitude limitations for that sector of the route. Their discussion was recorded, to the effect that actual versus forecast temps at altitude did not permit a climb to a higher altitude that they had planned for (or left as an option) before takeoff. /B]

Not inexplicable and the reason is this: The evidence. My take is that the PF was unaware of his climb, and his instruments were not helping him to decide the correct attitude, plus a concern for Overspeed. Another factor could be an uncommanded ascent. Make no mistake, his pull on the stick caused climb, but can we eliminate the a/c climbing on her own? In additiion to? The VS and the altitude gained are remarkable, and the initial inputs of PF were not commensurate with ROC, imho. How can the a/c sustain 1.68 g and the cockpit not remark? ROLL masking the VS accelerations? Columnar airmass, ~ +100?

Organfreak

Lyman,
B-but Lyman, that was supposed to have gone out with high-button shoes, or at least hula hoops, after numerous accidents were blamed on poor/no CRM. How could, in this day and age, cultural customs trump professional procedure???

And, if there was such a problem, it seems to point to: they would rather die (and kill everyone else) than speak out-of-turn! It's hard to fathom. I'm wondering something that can never be answered: Were they both so panicked that they froze and forgot everything? (Deer, headlights.) It sure looks that way.

Lyman

Howdy Organfreak.

Given the evidence, that the yoke was certain salvation, and nothing of consequence happened, you are correct in assuming some sort of hard to explain vector of behaviour. I count three times that I was very close to dying, once in a hang glider.

I did everything I could do, in all three situations, and each time I experienced a very calm feeling; in looking back, I could not have done anything differently.

BTW. I'd like to recapture that feeling, and like most humans make it my way of life. But without the danger.....

jcjeant

Hi,

DW
The question can be also ... why Boeing keep the yoke even on their last aircraft conception ?
Why they don't choice the SS ? .. as it's less weight .. etc ...

aguadalte

Diesel8:
Well, my friend, you made me go back to my logbook only to find out that I have about 7760 fh on FBW aircraft and 7740 fh on non-FBW.

I guess I'm a lucky guy

DozyWannabe

In part because it gave them a selling point by taking advantage of the backlash among some following the A320's entry into service. FBW as a concept was already proven, so they could focus on the backdrive software, which was probably more complex than anything Airbus could have attempted back in 1982.

That was all window-dressing really though - where Airbus had and still have an unassailable lead over Boeing is the ease of conversion between types - in which the design of the Airbus FBW flight deck played a crucial role. Because there is more commonality between the Airbus FBW types than could be remotely possible between Boeing's, it didn't make sense for Boeing to try to retrofit all their existing types with 777-based controls. In that sense, Boeing having been around for longer and being responsible for the most popular airliner in the world actually proved a disadvantage.

[EDIT : Just to try and clarify - the debate over Airbus, FBW and automation frequently misses the point in a lot of ways. The A320's automation is not a great deal more advanced than that of the 757 (Boeing's 3rd-gen narrowbody at the time).

The fact is that Airbus found themselves in an almost unique position in the early 1980s. Because their only existing types catered for a specific market, and because that market was near-saturated, it meant that they could expand without encumbering themselves with A300 commonality.

One of the great misunderstandings about Airbus's much-publicised cost savings to airlines with the new FBW types was how the savings were achieved. It wasn't really to do with greater automation, and it definitely wasn't an attempt to de-skill pilots - it was to do with ease of conversion. By designing the flight deck of their narrowbody and new widebody types to have unprecedented commonality with each other, theoretically the cost to airlines of conversion training could be drastically reduced. Boeing had made inroads on this theory by designing the 757 and 767's flight decks to be very close functionally, but Boeing still had the legacy types (727, 737, 747) to contend with. Airbus had a relatively clean run at doing it across their entire range, with the exception of the A300/310 (which had nowhere near the market penetration of the older Boeing types).

As such, the fundamental design brief was to put together a flight deck that could be installed in anything from a twin-engined puddle-jumper to a four-engined widebody long-hauler and as near as possible have the only difference to the pilot be the reference numbers. Obviously if you're feeding back the control surface resistance to the stick that's not possible - so with the help of some of the best pilots in Europe they set about making a design which would feed back all the information available in a more traditional setup, but would fulfil the design brief. Some compromises had to be made, but the position Airbus enjoys now is a testament to the soundness of the design they came up with. ]

Lyman

I think the Bus markets well, but let us not leave out the ease of transitioning to flight in the first place, the entry level. How much of this "consumer friendly" sales Pitch has to do with ease of operation? That is the foundation for the chronic knock on the Bus cockpit, imho.

DozyWannabe

All of it, Lyman - that's why people like Gordon Corps were onboard.

Leaving aside the sidesticks for a moment, the rest of the design was probably one of the most ergonomically friendly in airliner history. One of the reasons I miss 411A is because he could wax lyrical on what a pig the early 707 cockpits were (and different for every customer initially!).

The fact that I could take off, follow the FD and land the sim with minimal instruction* - having not been in a real aircraft cockpit since I last climbed out of an AEF Chuckmunk 18 years ago - shows that it is pretty intuitive to the novice.

[* - Not to underplay the instruction I did get, which was concise, to the point and everything I needed to do it - I can't thank those involved enough. ]

IcePack

Lyman re your post of not reacting to Stall Stall.
A lot of years ago I was involved in an investigation into a wheels up arrival.
The GPWS was triggering for 17 seconds. None of the 3 crew heard it. However it was as clear as a bell on the CVR area mike. 1st thing to go under stress is hearing so I guess the 447 didn't hear the stall warning.

Organfreak

jcjeant wrote:
I realize that your question is only rhetorical, but I have read recently (but can't remember where, dammit!) Boeing's statement of their FBW design philosophy. It made it clear that they insist upon realistic FC feedback.

DozyWannabe

The question then becomes, why do they insist on that - given that the realistic feedback is entirely artificial?

I had a pop at answering that question above. I believe it has more to do with corporate philosophy and the need to stake out different ground from their competitors than anything else - plus they weren't in a position to reap the benefit of radically overhauling their control methodology in the way that Airbus were.

@IcePack - there are visual stall warning cues too, including the bright red master caution light going off right in front of you and various cues on the PFD.

(And whatever else you may think of Airbus, they were on the money - going from a distant third in terms of western airliner sales to being able to duke it out with Boeing for the crown on an annual basis.)

Lyman (below) - spelling corrected.

Lyman

Chipmonk....that is a Catholic deHavilland?

Organfreak

DW:
Come on, Dozy, you know the answer as well as anyone. Because it is entirely realistic. It does its job, it works.

As to your second point, I'm sure that's true.

DW:
Great Jumping Jehosaphat! That is so disingenuous I forgot to sneer. MD merged into Boeing. That pretty much took care of the rest of the competition. (Though Boeing titularly bought-out MD, Boeing's board and leaders suddenly became largely MD, and that's when they began dropping lots of balls. Run by money wonks instead of engineer wonks.)

But I digress.

HazelNuts39

Because American pilots are more conservative than their European collegues?