Machinbird

Owain Glyndwr
That seems to be a pretty good answer (Once I figured out that centering the ball is a form of turn coordination-even if flying straight and level.) And yes, you do not need much rudder in most jets in cruise (CONF 0). Therefore it would seem that the Ny input is used solely in higher numbered Configurations for turn coordination.

Since I have seen a number of "unmasking" events in other aircraft, and the switch to ALT2 from Normal law, opens possibilities for unmasking events, I will reserve final judgement. Maybe looking at the yaw trim problem from the other direction, ie Normal law masking a slight out of trim condition rather than Alt 2 law creating a condition.

Nemrytter

Hi, I have two questions about the weather conditions experienced by AF447. A search hasn't shown up anything similar, so hopefully it's not duplicating what's been said before.

First: What was the OAT during the icing formation? I found some numbers in the BEA report that indicate a temperature of around -38C. Is that correct?

Second: Did the flight deck get any weather updates in-flight, or was their information based on pre-departure forecasts and their radar?

LIke I say, hopefully these haven't been discussed already, if they have it'd be great to get a link towards the relevant posts!

mm43

AF447 thread, page 27 will be a good place to start.

Also check the links to the three Interim Reports from the BEA which can be found on the 1st page of this current thread. You could also put "AF447 search index" (including the quotes) into the Google search engine and use the customized search engine that will be returned.

Nemrytter

Thanks for the tips. I've already read the interim reports but the info in the thread you link to is interesting.

roulishollandais

It is in French, excuse me :

franceinter y a-t-il trop de pilotes dans l'avion

They did not seem to have heard anything about a stall in RIO-PAR flight ! But everything is merveillous in french airlines and French pilot schools !

http://www.franceinter.fr/emission-s...s-dans-l-avion

april 30. 2012

Yves DESHAYES (CDB AF) Président du SNPL (Syndicat National des Pilotes de Ligne)

Michel POLACKO journaliste radio spécialiste aeronautique et défense Franceinfo

Christian MOREL sociologue autor de "Les décisions absurdes : comment les éviter", tome 2 Edition Gallimard Paris

infrequentflyer789

Sooner or later they are going to have to blame French pilots, French airline, French plane, or French pitots.

Might be why the report is taking so long...

bubbers44

I wonder how many of those 2900 hrs the PF had actually handflying and not monitoring? Not many I am sure and that is probably why he pulled up into a full stall at high altitude because he didn't understand he was in Alt law and had no stall protection. The second pilot in the left seat couldn't see what he was doing so got confused too. Then the captain comes up at the end and can't see what they are doing either with his limited time watching so can't see what he is doing with the SS. Why would any pilot at FL350 pull full back on the controls because he lost airspeed? All jets have loss of airspeed checklists showing proper pitch and power for weight and altitude. None say pull up to the stops. Boeings wouldn't let pilots do that. Unless both pilots were incredibly stupid.

Old Carthusian

A very good question Bubbers but it rather suggests that he was unaware of the aircraft and how it functioned. Never a good thing. The PNFs display should have supplied him with all the information he needed to determine the aircraft's attitude (but missing the IAS of course). But rest assured you can pulll the same trick in a Boeing - before this accident no doubt it was thought you couldn't stall an Airbus in this way. This accident is not aircraft design philosophy related.

bubbers44

It wasn't that long ago, 9 years, that we could all hand fly and an autopilot disconnect was a non event. Now that I have retired I hope things haven't changed much. Pilots need to be in control of their aircraft at all times. Automation is there to assist them, not fly the airplane instead of them. The great pilots I flew with 9 years ago knew how to hand fly. They didn't have a problem so only the new ones with little real hands on experience are the problem. All pilots should be competent at hand flying because your passengers deserve this.

roulishollandais

It would be necessary that the pilots have control before to start the system, and may reverse initial conditions :

In the (relative) "old" time the pilot opened brackets for the PA/system. The pilot was "MASTER" in the effective aircraft , and the PA/system was "SLAVE" .

In the bad designed today's effective aricraft, the system puts pilots between brackets before he is sitting in the cockpit . The system is "MASTER" in the effective aircraft , and the pilot is "SLAVE" . ECAM throws him biscuits to keep him busy .

In the 8 billions Ariane 501 crash (Arianespace 4.june1996) the initial condition had been added, to compute the ground position of the rocket. At take-off the bug needed only 37 seconds to show it was the master of the rocket.
The perfect inquiry conducted by Jacques-Louis LIONS finished in less than 24 hours, written in 15 days, published in 6 weeks, showed that in computer systems we must not trust the system if we see no failures, but we must take it for faulty so long we have not been able to Proof it is safe, with all the best knowlege at this time.

promani

All pilots should be competent at hand flying because your passengers deserve this.

Obviously the airlines and their shareholders, in the case of AF447 the French Govt, do not agree with you. It is all about making a profit. As someone said in one of these threads, I think, that if airlines had their way there would be no flight crew, just like no staff on some subways.

Lyman

promani. see roulishollandais. I agree with both of you. It is ironic that the tables are turned on those whose allegiance is to machinery, that when faulted, the mechanism cannot solve its problem. It is done, finished. No escape....but for the humans who control the mechanism, who can reason, and problem solve.

Stubborn fealty to a false god. Make no mistake, the 447 flight was doomed at UAS onset, doomed, without the flight crew. That she crashed is perhaps due poor communication among the three pilot, but the a/c was lost prior anyway.

The problem was soluble up to well into STALL (likely), but only by the hands of man. Yet it is pilots who take the blame for the shortcomings of the automations. Once the a/c gives up, there is no pathway back to stable, save for the intervention of the safety pilots. The interventions were inadequate, but those who believe in pilotless travel would be wise to consider that because the rescuers failed, the new way may not be safe without at least the chance of salvation. Keep the Mark I, yes?

gums

Salute!

Good grief, are we now supposed to train our pilots to do fault analysis for 99% of the flight and then decide if Hal is doing O.K., and then "save the day" when Hal says "I can't do any more and don't know what's wrong"? BEAM ME UP!

Even if that approach is taken, then the humans still have to have the abilities and skills and judgement to fly the jet and get all the folks to the ramp. And they better have lottsa training for unusual flight conditions and loss of indicators.

Only reason I cut the crew some slack is the complicated reversion laws, unusual warning sounds and displays and such. I still think the PF thot he couldn't stall the jet due to the AoA protections ( poor term, but for another thread). Otherwise, I blame the crew.

I do not agree that the jet is so well designed that it is fool proof. Nor do I buy the argument that it did what it was supposed to, so no problem with the jet. I throw the foul flag, and point to the displays, confusing warnings, and on and on....

I see no point in discussing the yaw dampers and sideslip angles and all that stuff. Best I can tell is that the jet was fairly controllable, even at an extreme AoA and slow speed. So an attaboy to Airbus aero folks. And many "aw $hits" to the display and sfwe folks and training program. Takes 20 of gums' "attaboys" to equal one "aw $hit".

My feeling is that most of the pilots here think that better training and more hand-flying is vital. And then there's the human factors such as displays, warnings and complicated control law reversions. Am I way off base?

I thank the Lord that the primitive FBW system I flew had AoA as the prime limit, and the gee and rate limits secondary. Our yaw damper for the rudder commands was decent, but prolly no better than any jet that flew from the mid-fifties.

I say again that you could not get into the stall or "deep stall" without zooming up at 70 or 80 degrees of pitch and let the jet zip past the control law limits, then settle into the infamous "deep stall". If you were rolling and such, it was really hard to do.

I look forward to the final report and recommendations. Will be extremely interesting.

bubbers44

gums, I agree, yaw had nothing to do with this crash. Pulling back on the SS for no reason did and they would have been better rolling off into a steep bank than pitching up into a deep stall. He must have thought he was stall protected and forgot he was in alternate law. I still would like to know of those 2900 hrs how many were flying and how many merely monitoring an autopilot.

When I upgraded to captain from the MD80 to the B737 200 I did a lot of hand flying in the 80 to get my basic skills back to what they were. Flying skills can not be maintained by monitoring, only by doing.

jcjeant

Assuming that this pilot fly only long haul .. and taking an average of 8 hours flight for each trip
Assuming that the pilot fly manually (generous here) ten minutes after take off and ten minutes before landing ( I'm being generous as it's already almost impossible he perform all take off and landings) .. this gives a manual flying experience (at low altitude) of 120 hours!

gums

So I look up the reversion laws and sub-laws and sub-sub-laws. Then read the footnotes and such, and then I get upset. Sorry, but I want/need something to hang my hat on.

And only thing I have if my touch and feel and experience. You know, "talk to me baby. What's this thing doing? I can help."

So Here's the notes from the A330 flight control reversion when outta basic control laws.

I was pretty good in school, but would have trouble on a test with these footnotes. Sheesh.

If WOW, then I don't care about other things not agreeing as long as the AOA probes are not all reading the same value and don't move when I pull or push a bit ( and would expect a warning of some kind). Of course, I could prolly "feel" some burble" "buffet" or wing rock or other things that let me know I am getting where I don't want to be.

So I do not let the 'bus design off the hook. I go with lottsa crew error in technique and coordination, but also question the basic design philosophy and training.

NeoFit

Hi,

Sure, if such UAS event hapened while taking off or approach, the pilots were able to think about MAN PITCH TRIM, because they are trained for (ONLY at low altitude). [remember TAMRON 1994 LFPO]

Is there anybody believing at FL370 that THS had gone away -13 degrees ?

chris weston

All pilots should be competent at hand flying because your passengers deserve this.

Bubbers, 289 absolutely agree.

But ..... they don't deserve this they need this. The distinction between the two verbs is vital.

infrequentflyer789

This keeps coming up, in various forms, and I'm not sure I understand why.

If never trained in alt law I can see why he maybe missed the display and pnf call of it, and even the stall warning didn't give him a clue... but why was he anywhere near protection envelope in the first place ? The protections are there, I thought, to stop inadvertently straying outside the envelope, and (some modes) to give maximum performance within the protection envelope for specific circumstances - e.g. emergency terrain avoidance. What lead PF to desire maximum climb performance and then assume he was protected ?

Or put another way, you say PF was thinking:

"I can pull back as hard as I like to get maximum climb, because the plane will protect me"

But before that must be the thought:

"I need to pull back hard to climb fast (for several 000 ft) because... <???>"

This is right at the start, before the stall, to be clear.

What's the blank ? Surely unless we can fill that in the thought-he-was-protected is not relevant, and we are back to LOC in pitch being inadvertent. What little CVR there is seems also to support that - PNF says "why are you climbing" not "pull up mountain ahead". PF response seems to indicate he doesn't believe or understand he is climbing, PNF then insists he is.

chrisN

2.5.12


IF, re: “ . . . pull back as hard as I like to get maximum climb . . .”

You seem to think he did this from the outset. He didn’t. If you look at the “stirring mayonnaise” chart,

[see:
http://www.pprune.org/tech-log/46839...ml#post6819601 ]

his pitch up inputs were neither full nor consistent at that time. Some have postulated that the stick back was inadvertent while he was using (too) large movements in roll. (PNF was telling him to make more gentle movements.)

It was after getting roll under control that he went to full stick back, AIUI.

Nobody knows what he thought or why, but one possibility is that after getting roll sorted, and the nose had started rising, with whatever alert noises were going off, he became confused; could not believe speeds, started to disbelieve some or all other indications, talked about crazy speeds, ended up stalled but ignoring the stall warning, had huge cockpit noise, (noted by somebody who has heard the CVR, it was reported) and thought, at least at times, that he had overspeed. So maybe he was pulling the nose up to try to slow down. Remember, at one stage he tried to use the airbrakes too, until PNF stopped him.