john_tullamarine

.. reminds me of a depressurisation many decades ago in Oz. The senior ATC chap was absolutely adamant that his man convey to the crew the need to don their masks.

Needless to say, the initial considerations of the emergency were long sorted out by the time the ATC messages managed to get through the ATC system and, finally, to the crew.

As I recall .. the crew, having rolled their eyes into the back of their heads, tactfully and diplomatically acknowledged the concern of the senior ATC man and went on about their routine business sorting out the remainder of their problems at the time.

I think that there comes a point where success depends on the crew, the crew's competence and experience, and the operator's training programs ... and there is precious little that third parties can do considering communications realities and time pressures ...

DozyWannabe

Hmm... Based on earlier discussions I think the idea that the aircraft had developed a right-roll tendency [EDIT: in and of itself] is at best debatable and in my opinion (for all that's worth) actually fairly unlikely. OK, so the data shows the flightpath post-disconnect and stall as being a descent biased to the right - but there are several factors that need to be borne in mind.

Firstly, we know that the AP disconnect occurred roughly simultaneously with a "bump" of turbulence that left the aircraft with a pitch attitude of slightly below zero and a slight bank to the right. From then on the PF took manual control and was making inputs virtually constantly from onset to impact, thus making it impossible to ascertain what the aircraft's response to zero control input would have been. Even in Alternate Law, the aircraft should have remained stable in pitch and bank until an input was made.

Secondly, we also know that the PF was making significant lateral inputs on top of the pitch commands - during the zoom climb this seems consistent with overcorrection, if not PIO. Looking at the DFDR data you can see that the right bank in this phase correlates with the input from the PF's stick - if he were correcting a right roll tendency the roll would occur even with the stick laterally neutral in the traces with an occasional correction to the left.

Finally, once the aircraft was into the stall regime any bank commands attempted via aileron would have been ineffective and inconsistent, as the wing needs to be flying in order for the ailerons to function correctly. The only way to effectively control bank past that point would be to recover from the stall and subsequently level the wings, or in an absolute worst-case scenario use the rudder very gingerly to get some degree of stability during the stall recovery sequence.

Additionally (and perhaps tangentially), there is no mention on the CVR of the aircraft exhibiting a right-roll tendency [EDIT: prior to stall]. Circumstantial I know - but in every case I know of where a specific and consistent control difficulty has come up, it's always mentioned by the crew.

bubbers44

I was joking about both going back and leaving the cockpit unattended to get a real pilot but they made things worse by what they did so might have been better off doing so. I have flown with some weak FO's but very rarely. Having two in the cockpit at the same time with no supervision was unheard of during my career. Hopefully this isn't our future in aviation to improve the bottom line by cutting costs.

bubbers44

How can their aircraft have a right rolling tendancy? We always trimmed our aircraft in level flight at cruise, wings level and adjusted the rudder trim to make it fly straight and level. Of course you have to normally turn the autopilot off in cruise to do this accurately so may be a problem for some. Once you are wings level and steady on heading the ball magically goes to the center so there are no right rolling tendancies. It has worked for decades and saves fuel too.

mm43

Might be useful to have another look at the discussion on this subject that went on in AF447 Thread No.5

BARKINGMAD

Since the current paranoia about hand flying in RVSM, how many F/Os and indeed current captains have had the pleasure and satisfaction, as well as the competence, to fly the 'frame at cruise altitude and even curent max ceiling?

I would not be surprised if neither of the AF447 F/Os had any significant useful current experience in the unusual handling characteristics of their craft at such altitudes, most handling experience now appears to be limited to the lower levels.

This may account for the oscillations observed from FDR, so why is this high-level handling skill being written out of the requirements for Public Transport pilots?

A few minutes in the simulator does NOT suffice to "train" our colleagues in such handling, which is occasionally required when the automatics give up.

Perhaps a climb to and leveloff at cruise altitude should be an item to be assessed in annual line checks, hopefully the presence of 3 fully qualified pilots in the flight deck would prevent the (rightfully) much feared altitude excursion but permit real life high-level handling?

Otherwise how will we get operating crew who are experienced and reasonably current in AIRCRAFT CONTROL at all parts of the legal operating envelope?

My fear, when I'm SLF, is that I'm boarding such a flight where (both of) the Magenta Kids are INCAPABLE of handling the aircraft in S&L at cruise altitude, never mind the trim runaway case where the problem will be compounded by forces and reactions never before experienced by those allegedly in charge.

So part of the UAS training should include a box in the line check form that the candidate is at least capable of handling the REAL aircraft in the cruise and hopefully when things start to go "twang", ALL of us are at least capable of keeping blue-side up, brown-side down whilst the problem is diagnosed and sorted?

I suspect that not only were the AF447 drivers confused by the performance instrument indications, but that the manner in which the 'frame reacted to control inputs was outside their experience, for the reasons I've just offered.

P S. For the beancounters and managers, such online training should not incur a cost penalty, except the automatics are not controlling the flight to cruise level so the odd kg of fuel might be consumed but immeasurable and trivial compared with the valuable experience and knowledge gained by crews?

DozyWannabe

Agreed with what you're saying there. The point I was trying to get at was that the aircraft's flightpath was caused by external factors, not a problem within the aircraft itself...

Linktrained

Barkingmad

With all the recording of the minute details of each flight now done, surely the amount of hand-flying done by each pilot at cruising level is already available.

In an earlier contribution I suggested that this might be called "447 Time", just to remind pilots of what MAY have been a contributing factor. It could or should, be practiced, at least initially, in areas and at times with the agreement of ATC.

As a very very new Second Officer I was expected and required by my Captains to be able to do just this, admittedly prior to RVSM, for alternate hours of cruising flight.

I was told " NOT TO WANDER ABOUT !"

I suppose that I must have met their standards. As a newish F/O i was the only other pilot on board, flying via Keflavik, Gander and Bermuda to Kingston and hand-flying for 4 hours on each leg (A/P U/S).

One of the 36 passengers weighed "27 stone". We saw that he HAD to be in TWO PLACES AT ONCE, but with an extra seat belt.

Flight time limitations came some years later.

AlphaZuluRomeo

I think it's a misinterpretation. When the heading changed (as per FDR) and the crew said "je suis à fond à… avec du gauchissement", the aircraft was already stalled (and for a long time).
That doesn't denote a right roll tendancy when it was still flying, as other posters already pointed above

xcitation

@ Dozy
The BEA has done this for you.
I should have clarified this earlier.
The pink line represents "Simulation without pilot input and with reconstructed wind".
http://www.bea.aero/fr/enquetes/vol....gure.64.en.png

So can we drop the speculation about what would have happened without pilot inputs? BEA says no barrel roll and no oscillations.

DozyWannabe

@xcitation:

Yes, I'm aware of that - allow me to rephrase as "that *particular* aircraft", as some were positing theories that it was damaged in some other way. For what it's worth, I'm of the opinion that the BEA are correct, and that other than the known issues there was nothing materially wrong with the aircraft itself.

xcitation

One hypothesis is that the PF pulled stick back because of loss of ASI and fears of a dive and over speed - possibly reinforced by the stall warning later.
Whilst ASI was not available the ground speed could have been used to gain a qualitative idea of going faster or slower e.g. seeing GS decay 400kts to 1000kts as he pulled up and began to hear <<STALL>> then stick forward and see GS increase and warning disappear.
Clearly GS is a terrible quantitive measure of AS on its own e.g. a nose dive would give a low GS and high AS, however combining it with attitude, altitude, vsi etc it could have been of use.
We know he should have followed UAS procedure however the PF appears to have chosen to chase a response from a/c to his flight control inputs. These inputs became more extreme as he dug a deeper hole in seeking response. Glancing at ground speed could have helped him observe the input/response and get some feel in the void.

Teldorserious

Still arguing over whether pilots should know how to fly straight and level?

The debate rages on! Hire experience or hire checklist reading robots.

Natstrackalpha

The letters CB just spring to mind, I wonder why that is?

xcitation

@Teldorserious
Are you saying experienced guys don't need checklists?
Those checklists are written in the blood of many brave aviators.
The one Apollo astronaut I knew had checklists for nearly everything.
Maybe you're exceptional and never use them but for us mere mortals they work well.
As often said here many accidents are by highly experienced pilots.

Linktrained

"Hire experience or..."
That experience had to be gained, somewhere.

And then kept in reasonable practice, too.

It is not " Just something that I did as a beginner and have been able (or forced) to forget ever since."

I had a F/O who allowed the aircraft to drift down towards
the opposing traffic flow, following an A/P failure. He appeared to have forgotten that the ordinary manual controls worked at cruising level, too !
He was able to practice, all the way home.

bubbers44

Pilots need to know how to read checklists and also handfly the plane. They just can't do one. We have seen some accidents recently that show how important airmanship is and not just being a checklist reader as previously said. Robots can do that but pilots can also fly an attitude and power to avoid AF447 type accidents. I know this is getting really boring but they should have not needed the captain in the cockpit to fix the problem. He would have fixed it.

roulishollandais

SOP and Check-lists look like written in context-free language, smell like context-free, have colour of context-free, but are NOT CONTEXT-FREE, will never be context-free, and translated in automation algorithms would get hidden bugs too.
Edit Add :
That does not mean don't use check lists and SOP, but don't be blind in using them. They are not perfect, sometimes missing.
I remember in my airline flying MD83 :
1. We had a long never trained emergency procedure in case of physical loss of an engine (rupture) . The check-list was more than one page. The first page finished with "continue page 58" (no more sure it was 58) , but page 58 was a false information, we had to continue on another page that I had time to discover in my armchair at home. I wanted to correct the mention "58" but I have never been allowed by the sector head. Happily engine do not often break and fly away.
2. We had no emergency procedure in case of dutch roll, but once we had dutch roll. Happily the captain had been taught in USA, could decide it was a dutch roll, and tried what had been said in USA "don't touch the control". Not perfect but it worked after great height loss

Clandestino

This thread and ten previous are treasure trove of information... for psychologist interested in obstinacy.

Xcitation's link is at least 10th time it is mentioned that analysis of "What would happen if no control input had been made" was performed and has shown very moderate roll and pitch excursions yet folks still harp about turbulence and unstable aeroplane.

Many a time were referenced parts of report that mention that crew was flying through area frequented by thunderstorms but they made a good job of avoiding and yet every now and then someone shouts "They entered CB!"

Interim 2 was very clear that almost every incident (about 30 of them) in cruise resulted in AP disconnect and degradation to alternate law but none resulted in any injury, damage, overstress or departing the envelope. Still we have folks shouting from their soapboxes of how difficult it is to manually fly the modern airliner at altitude and that we need more actual practice in doing so or otherwise we'll face dire consequences.

Of course, there are usual suspects whose last escapade was to hint that what happened to sloppily maintained and then tragically slipshod test flown 320 is in some mysterious way applicable to all FBW Airbi.

While there were a lot of posts that were relevant, informative and stemming from some excellent expert analysis, if we were to employ noise reduction technique on the AF447 threads we'd be hard pressed to fill a single thread with signal, let alone ten.

roulishollandais

It shows that PPRuNe is not an adept of the "final solution".