AF447 wreckage found
RWA-
Amongst all the hot air generated on this topic, I think your analysis may pretty well hit the nail on the head. Unfortunately, a lot of people may not be seeing things in quite the same light. Quite a few posts ago, I made the comment that a very small pull on the stick at high altitude, if you were heavy and close to max altitude, (should'nt be there in the first place, especially if turbulence is present, as the FCTM clearly states), could put you in stick shaker very quickly, together with a zoom up into "coffin corner" territory, (don' t hear much talk about that phrase these days, do we!)
Combine that startle factor (for the unprepared/untrained) with a full up THS and you can see why a certain element of confusion may have arisen. I think we will eventually find there is more to this than simple pilot error. Not bashing Airbus, (they build great aircraft, and I speak from experience of operating the type as well as Boeing), but nevertheless Toulouse will have some explaining to do here.
Regrettably, over the years, Airbus have usually blamed the pilots in most accidents ("they did not understand the systems"), but then they quietly go ahead and change some bit of software/hardware.
be interesting to know whether Airbus, Air France, or the BEA had warned pilots that this sort of 'impasse' could occur; and indeed had occurred, as far back as Perpignan in 2008? I very much doubt it........
Combine that startle factor (for the unprepared/untrained) with a full up THS and you can see why a certain element of confusion may have arisen. I think we will eventually find there is more to this than simple pilot error. Not bashing Airbus, (they build great aircraft, and I speak from experience of operating the type as well as Boeing), but nevertheless Toulouse will have some explaining to do here.
Regrettably, over the years, Airbus have usually blamed the pilots in most accidents ("they did not understand the systems"), but then they quietly go ahead and change some bit of software/hardware.
Last edited by Phantom Driver; 6th Aug 2011 at 17:36.
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But it seems to have been up (for whatever reason) and stayed up. Has the BEA explained why?
He didn't keep the stick forward far enough or long enough to move the elevator back to neutral, and then into the "down" position. The THS would only have started moving "down" again once the elevators were pushed beyond neutral.
The THS behaved exactly as designed.
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Neither, importantly, did he exercise the option to re-trim the aircraft manually using the trim wheels, which would have taken significantly less time - presumably because he was not taught how.
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Hi,
One from head is Mount St Odile (some changes after .. despite pilots made some mistake about descent rate settings if remember well) about interface
Not wishing to sound facetious, but would you care to provide examples of where this has been the case any later than, say, 1994 (when the death of senior test pilot Nick Warner on a demonstration flight caused them to re-examine their priorites)?
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The systems only imposed the 13 degree up angle because the pilot asked for it by backwards pressure on the SS that increased the pitch angle to the point where the aircraft stalled - the system was doing exactly what the pilot requested.
If I turn the thermostat up on my heating system I wouldn't expect the temperature to get hottor and hotter indefinitely.
If I turn the steering wheel of my car I wouldn't expect the turn to get tighter and tighter until the steering rack is on full lock.
Even the accelerator pedal on my car mostly behaves like a speed control rather than an accelerator. Once I have reached the desired speed I don't lift off the pedal to maintain that speed. I have to keep it pressed.
What other familiar systems have a "runaway" behavior like the auto trim?
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puzzling...
One thing that is puzzling me is the speed of PF's hand on his movements aft and forward on the sidestick.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
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Originally Posted by Denise Moore
Why the initial climb?
When AP disconnected the a/c was pointed down slightly (Pitch=0 deg) and it was descending. Also altimeter might have jumped down a few hundred feet because of impared pitots and air temperature sensors due to a possible ice build up from the strom they were in.
Pilots are trained to maintain altitude in cruise so he correctly pulls the stick back to keep at FL350. It appears he was in a down draft because it took a large stick deflection to maintain altitude for a few seconds. At high altitude and speed his strong stick input has dangerous effects and a stall warning is triggered. He then notices airspeed is broken. We can speculate that he was distracted, took his attention away from altitude and tried to process what was happening. More errors occur further distracting him. Finally the a/c has risen to FL375 before he figures out he has climbed, he had exited the downdraft and had held the nose up attitude.
Climbing the aircraft without adding power results in a drop in speed. Same as a pendulum swing up. Now a/c was in a dangerous high altitude and low speed condition with impared flight controls (ALT LAW).
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What other familiar systems have a "runaway" behavior like the auto trim?
If I turn the thermostat up on my heating system I wouldn't expect the temperature to get hottor and hotter indefinitely
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Originally Posted by Rob21
puzzling...
One thing that is puzzling me is the speed of PF's hand on his movements aft and forward on the sidestick.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
One thing that is puzzling me is the speed of PF's hand on his movements aft and forward on the sidestick.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
Looks to me like he was over sticking then having to correct for each input.
Instead i imagine he should have used smooth gentle deflections.
Ever seen a nervous person drive a car like this? Constantly twitching the wheel having to correct over steer in each direction. A smooth small input is all that is required. I have also seen people use accelerator and brake in the same way, constantly pressing one peddle then the other. Instead of just calmly pressing accelerator to desired speed. You are pulled back and forwards in your seat. Can't say i've seen that behaviour much in pilots.
Totally speculative - is this consistent with anxious/un-trained behaviour from the onset.
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Flickering Flight Display
xcitation, it looks to me that he is "chasing" a flickering PFD.
It was an attitude indicator, because he is correcting roll also.
But anyway, at least to my knowledge, the normal is to be "quick" on ailerons and "easy" on elevators.
The graphics show the opposite.
It was an attitude indicator, because he is correcting roll also.
But anyway, at least to my knowledge, the normal is to be "quick" on ailerons and "easy" on elevators.
The graphics show the opposite.
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(The fact that Air Inter specifically ordered A320s with GPWS deleted didn't help in that case either)
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One thing that is puzzling me is the speed of PF's hand on his movements aft and forward on the sidestick.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
__
I've flown with a few FO's that did that all the time hand flying. They have plenty of experience but don't seem to trust themselves hand flying so keep doing PIO's to touchdown. You would think some hands on flying would stop this but a lot of airlines discourage hand flying these days. The PF in the AF447 crash didn't seem to have a clue when the automatics failed. They need to look at the Bob Hoover you tube flick where he pours an iced tea pitcher into a glass while inverted in a roll in a Shrike on page 83 of the tech forum. I know Bob and he knows how to fly an airplane. He will be at Reno at the air races in mid Sept.But he has retired from demo flying.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second...
And with significant amplitude also.
What was he chasing?
__
I've flown with a few FO's that did that all the time hand flying. They have plenty of experience but don't seem to trust themselves hand flying so keep doing PIO's to touchdown. You would think some hands on flying would stop this but a lot of airlines discourage hand flying these days. The PF in the AF447 crash didn't seem to have a clue when the automatics failed. They need to look at the Bob Hoover you tube flick where he pours an iced tea pitcher into a glass while inverted in a roll in a Shrike on page 83 of the tech forum. I know Bob and he knows how to fly an airplane. He will be at Reno at the air races in mid Sept.But he has retired from demo flying.
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That was in 1992 (2 years before the cutoff date I specified),
So what are you implying?That there was conspiracy to deceive and obfuscate prior 1994 but everything 's been above board since?
Would you say there are any latent dangers in this autotrim design in abnormal ops or that the pilots always instantly and intuitively recognize the transition from auto to manual?
Would you say that the stall inhibit below 60 is excusable in design terms as its outside the realms of probability?
Would you say that the SS is ideal in a multi crew environment especially when considering scenarios where stick input must be timely and CORRECT(stall/x-wind/sev turb etc)?They have the stick in fighters but thats one man.Why did AIrbus employ it in commercial airliners?To be NEW?You seem to be an avid Airbus apologist so I'd like to know.
Do you have an opinion on why BEA withdrew the stall logic recommendation(factors affecting safety can and must be included in initial/interim reports but maybe theres a valid reason)?
Do you have an opinion on why no mention was made of the Captain's decision to leave the cockpit even though he now appears to have known that weather was up ahead?
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Not at all. They were overconfident in the abilites of their systems prior to 1994, that's for certain - and as such predisposed to put things down to pilot error when interface issues should have been looked at (the dual-mode Vertical Speed and Flight Path Angle in the Honeywell FMC being a major case in point, but the same computers were used in other manufacturer's aircraft). Airbus weren't alone in trying to point the finger at pilots in the '90s - Aircraft manufacturers are billion-dollar corporations open to massive liabilities claims and as such their legal departments will tend to demand it - look at how Boeing tried to pass the 737 rudder PCU issue off as pilot error until the NTSB had the "eureka" moment and tried a thermal shock test.
Would you say there are any latent dangers in this autotrim design in abnormal ops or that the pilots always instantly and intuitively recognize the transition from auto to manual?
Would you say that the stall inhibit below 60 is excusable in design terms as its outside the realms of probability?
Would you say that the SS is ideal in a multi crew environment especially when considering scenarios where stick input must be timely and CORRECT(stall/x-wind/sev turb etc)?They have the stick in fighters but thats one man.Why did AIrbus employ it in commercial airliners?To be NEW?You seem to be an avid Airbus apologist so I'd like to know.
Do you have an opinion on why BEA withdrew the stall logic recommendation(factors affecting safety can and must be included in initial/interim reports but maybe theres a valid reason)?
Do you have an opinion on why no mention was made of the Captain's decision to leave the cockpit even though he now appears to have known that weather was up ahead?
Last edited by DozyWannabe; 7th Aug 2011 at 02:07.
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Do you have an opinion on why BEA withdrew the stall logic recommendation(factors affecting safety can and must be included in initial/interim reports but maybe theres a valid reason)?
communiqué 3 août 2011
Google site translation:
Google Vertaling
Transcrypt of press meeting is also now available (english)
Transcript de la conférence de presse du 29 juillet 2011
Last edited by Jetdriver; 7th Aug 2011 at 03:11.
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If the PNF had a yoke in front of him flailing all over the place mostly in his lap don't you think he would have responded and put it where it was required to be for the no airspeed situation? I know the yoke costs money and weight but isn't it a wonderful way to see what your fellow pilot is doing? Maybe Airbus should put yokes back in their aircraft.
What the lawyers lawsuits are going to cost them negates all the years of SS controls to reduce weight and cost.
This could happen again.
Recovering a Cessna 152 from a students stall is easy with dual yokes. It would be more problematic with a side stick of Airbus design.
What the lawyers lawsuits are going to cost them negates all the years of SS controls to reduce weight and cost.
This could happen again.
Recovering a Cessna 152 from a students stall is easy with dual yokes. It would be more problematic with a side stick of Airbus design.
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One would hope that by the time someone has ended up in the flight deck of an airliner that they would have the requisite training for controlling the aircraft at that level (in terms of ability and altitude!). Airbus certainly haven't condoned pilots being certified without that training, but it would appear Air France let it happen anyway. Why the desire to crucify Airbus, when Air France seem to be the problem here?
Airbus's ace-up-the-sleeve has always been the ease of type conversion between their narrowbody short-haul types and their widebody long-haul types - weight saving was simply an added bonus. The advantages of starting from a clean sheet in that manner seemed at the time to have provoked a severe case of sour grapes from the other side of the Atlantic, which at one point considered the monopoly of western airliner design it's god-given right. The early years of competition between the two were bitter, but it seems to have resolved into a more friendly rivalry these days - unfortunately some seem to not to want to let it go.