Air Asia Indonesia Lost Contact from Surabaya to Singapore
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Originally Posted by Volume
It is not required to fly full stalls in flight testing.
I cannot believe the uniformed nonsense being posted in respect of transport category aircraft stall testing, stall characteristics and what is required to demonstrate compliance with the certification standards.
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no need to kill a lot of pilots to teach basics
NigelOnDraft: Sorry , but -- without debating the cost & headaches of teaching people how to really fly -- I find the conclusion that this "will kill a lot of pilots" unjustified. In more than 20 years of teaching advanced aerobatics, as well as stalls/spin and unusual attitudes (including, for a time, dozens and dozens of Ab Initio China & Gulf Airline students) I, and my then colleagues, did not have a single aerobatic accident. Pray tell why this should change.
"The solution, if we wish to reduce LoC accidents (which are very rare), is to ensure pilots are genuinely competent in attitude flying, stalls even spins, UP recoveries - and keep current 2-3 times a year minimum. That is an awful lot of aerobatic aircraft hire, and will kill a lot of pilots in accidents. It won't happen, and I suspect we will just continue to see a small number of LoC accidents...
"The solution, if we wish to reduce LoC accidents (which are very rare), is to ensure pilots are genuinely competent in attitude flying, stalls even spins, UP recoveries - and keep current 2-3 times a year minimum. That is an awful lot of aerobatic aircraft hire, and will kill a lot of pilots in accidents. It won't happen, and I suspect we will just continue to see a small number of LoC accidents...
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@zzuf
I take it you meant "uninformed nonsense", in which case I would simply say that Gysbreght is better informed than most posters here on certification as John T may well confirm.
I cannot believe the uniformed nonsense being posted in respect of transport category aircraft stall testing, stall characteristics and what is required to demonstrate compliance with the certification standards.
zzuf is right.
Most comments on stalling are by those who have never stalled a swept wing jet at high altitude except once or twice in a simulator and even then not in a massive Cb at night. Certification is not an absolute safety measure; merely a best practice, commercial option that meet statistical requirements.
a
Most comments on stalling are by those who have never stalled a swept wing jet at high altitude except once or twice in a simulator and even then not in a massive Cb at night. Certification is not an absolute safety measure; merely a best practice, commercial option that meet statistical requirements.
a
Owain,
JT will also confirm that I was CTP for a regulatory authority. As this is about A320 I must add that I spent plenty of time with the late Nick Warner during various evaluations including stalling.
Cheers
JT will also confirm that I was CTP for a regulatory authority. As this is about A320 I must add that I spent plenty of time with the late Nick Warner during various evaluations including stalling.
Cheers
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Does anyone know what is the speed of response time of the THS ?
Mechanically it is adjusted by a Jackscrew that is wound in or out by motors... Looking at a previous FDR graph of a/p control input, to actual movement, it seems as if it takes in the order of 15 seconds to travel.
In other words the elevator control is not as responsive as on an aerobatic airplane.
Mechanically it is adjusted by a Jackscrew that is wound in or out by motors... Looking at a previous FDR graph of a/p control input, to actual movement, it seems as if it takes in the order of 15 seconds to travel.
In other words the elevator control is not as responsive as on an aerobatic airplane.
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Originally Posted by zzuf
JT will also confirm that I was CTP for a regulatory authority. As this is about A320 I must add that I spent plenty of time with the late Nick Warner during various evaluations including stalling.
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From the BEA report on AF 447:
"When there are no protections left, the aeroplane no longer possesses positive longitudinal static stability even on approach to stall. This absence specifically results in the fact that it is not necessary to make or increase a nose-up input to compensate for a loss of speed while maintaining aeroplane altitude. This behaviour, even if it may appear contrary to some provisions in the basic regulations, was judged to be acceptable by the certification authorities by taking into account special conditions and interpretation material. Indeed, the presence of flight envelope protections makes neutral longitudinal static stability acceptable.
However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to its point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the sidestick. It appears that this absence of positive static stability could have contributed to the PF not identifying the approach to stall."
"When there are no protections left, the aeroplane no longer possesses positive longitudinal static stability even on approach to stall. This absence specifically results in the fact that it is not necessary to make or increase a nose-up input to compensate for a loss of speed while maintaining aeroplane altitude. This behaviour, even if it may appear contrary to some provisions in the basic regulations, was judged to be acceptable by the certification authorities by taking into account special conditions and interpretation material. Indeed, the presence of flight envelope protections makes neutral longitudinal static stability acceptable.
However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to its point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the sidestick. It appears that this absence of positive static stability could have contributed to the PF not identifying the approach to stall."
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Work together
Sorry but even as a non pilot, all this talk about 'push the stick forward and you're saved' is bit insensitive on this thread without knowing what happened.
It certainly didn't help 2 very respectable pilots on D-AXLA A320-232 over Perpignan when THS stayed nose up, with the combination of the AOA sensors freezing and normal law dropping out they were unable to save it with the above aforementioned method. After reading the report, i was worried by the lack of notification to the pilots, in that moment id expect 'USE MAN PITCH TRIM' to be slapping me round the face.
Or a clear indication:
Warning - Normal law FAIL STATUS NOW MANUAL
Cause - AOA/ADIR mismatch(or the like)
Result - USE MAN PITCH TRIM(?(perhaps added flashing if stick forward/backward exceeds Xseconds)) or AUTO PITCH TRIM DISABLED!
Would of been even nicer. (In this instance above i believe the PITCH TRIM warning dropped off the display shortly after ie changing flight law.) i stand to be corrected.
Then again what if the warning is wrong and all of it is sending you up the garden path?
If something similar had happened here im not sure id want to be on-board with ANY pilot at FL25(risky i know) or FL370, in that moment attempting to recover a stall. IMHO the transition from 'automated' to 'manual' and not in 'neutral trim' in the wrong moment without any clear reason is a worry, using any automated transportation.
As we have learnt even the most simple things in that moment to react can go undetected (flaps not extended on takeoff due to FB pulled on warning circuit muting the reminder to pilots they're not extended). Whilst not automated, had there been a clear warning, reaction should/could of saved the day.
I'm also shocked to read about lack of stall training due to lack of capability to do so for some aircraft. And still we have not put more pressure on all airlines to enforce real time streaming on capable aircraft with the rest to follow. MH370 whilst is rare, it needs to be answered it cannot be swiped aside as a statistic as some have mentioned here.
On the plus, I salute the many informative posters on here who clearly are outstanding professionals in their field and appreciate their fascinating analysis and input. I hope all of this debate can be focused on making our airways safer, negating the swiss cheese effect ever happening. Hoping no more families suffer this loss of professionals doing their job and PAX in this way, once we have the ACTUAL cause from the experts.
Anyway what do i know, i can barely fly a quadcopter!
It certainly didn't help 2 very respectable pilots on D-AXLA A320-232 over Perpignan when THS stayed nose up, with the combination of the AOA sensors freezing and normal law dropping out they were unable to save it with the above aforementioned method. After reading the report, i was worried by the lack of notification to the pilots, in that moment id expect 'USE MAN PITCH TRIM' to be slapping me round the face.
Or a clear indication:
Warning - Normal law FAIL STATUS NOW MANUAL
Cause - AOA/ADIR mismatch(or the like)
Result - USE MAN PITCH TRIM(?(perhaps added flashing if stick forward/backward exceeds Xseconds)) or AUTO PITCH TRIM DISABLED!
Would of been even nicer. (In this instance above i believe the PITCH TRIM warning dropped off the display shortly after ie changing flight law.) i stand to be corrected.
Then again what if the warning is wrong and all of it is sending you up the garden path?
If something similar had happened here im not sure id want to be on-board with ANY pilot at FL25(risky i know) or FL370, in that moment attempting to recover a stall. IMHO the transition from 'automated' to 'manual' and not in 'neutral trim' in the wrong moment without any clear reason is a worry, using any automated transportation.
As we have learnt even the most simple things in that moment to react can go undetected (flaps not extended on takeoff due to FB pulled on warning circuit muting the reminder to pilots they're not extended). Whilst not automated, had there been a clear warning, reaction should/could of saved the day.
I'm also shocked to read about lack of stall training due to lack of capability to do so for some aircraft. And still we have not put more pressure on all airlines to enforce real time streaming on capable aircraft with the rest to follow. MH370 whilst is rare, it needs to be answered it cannot be swiped aside as a statistic as some have mentioned here.
On the plus, I salute the many informative posters on here who clearly are outstanding professionals in their field and appreciate their fascinating analysis and input. I hope all of this debate can be focused on making our airways safer, negating the swiss cheese effect ever happening. Hoping no more families suffer this loss of professionals doing their job and PAX in this way, once we have the ACTUAL cause from the experts.
Anyway what do i know, i can barely fly a quadcopter!