Airbus crash/training flight
However as I understand, it is being fairly strongly sugested in some quarters, that in this incident there was a sudden & very excessive pitch up. Was this not exactly what happened a few months ago to the Airbus over North West Australia? Not making any point at all, but might this be food for thought?
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Originally Posted by hetfield
Autothrust pulls suddenly the speed back in cruise flight to achieve Vapp, but stops at green dot (protection), nobody knows why.....
Originally Posted by kaikohe76
Was this not exactly what happened a few months ago to the Airbus over North West Australia?
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20 January 2009
"The remains of four of the five New Zealanders lost in the A320 accident in France will arrive in Auckland accompanied by some family members and Air New Zealand Chief Executive Officer Rob Fyfe later this morning.The group will arrive in Auckland on NZ38 at around 11am today (NZ time).
When all other passengers have disembarked the Boeing 747-400, the aircraft with the families and remains of the lost men will be towed to an Air New Zealand hangar to be welcomed home by family, friends and several hundred colleagues in a private ceremony around midday."
"The remains of four of the five New Zealanders lost in the A320 accident in France will arrive in Auckland accompanied by some family members and Air New Zealand Chief Executive Officer Rob Fyfe later this morning.
The group will arrive in Auckland on NZ38 at around 11am today (NZ time). When all other passengers have disembarked the Boeing 747-400, the aircraft with the families and remains of the lost men will be towed to an Air New Zealand hangar to be welcomed home by family, friends and several hundred colleagues in a private ceremony around midday."
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A dozen years ago, I was told by a UAL training Capt. they had a 757 on low approach to KLAX when an engine (FADEC P&W) went full thrust. They were climbing faster than ATC could clear them, and got it sorted out at altitude.
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After the report I have read on the page 22 of this forum, I might have possible explanation of what happened. They said, there was some sudden surge of engine power, pitch up and than it came down. What if they slowed down the aircraft to a point of alfa-floor activation (don't know for what reason, but may be inadvertantly) and the engines at that moment did not spool up evenly? Alpha floor comes on, if you slow down to a critical angle of attack. It automatically gives toga (max power) to both engines. It is supposed to get you out of low energy situation. But if max power comes on at low speed and one engine spools up and the other is slow to spool up, it would be a perfect introduction into a spin (slow and yawing). Of course, all this is just an idea. We still have to wait for the official investigation.
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There should be ample rudder authority to control the yaw in the case of assymetric spool up. The aircraft can cope with a single-engine go around from low speed without any problems at all. I'm also fairly confident that alpha floor remains operative in the event of a single engine failure, which means it has been certified to operate in conditions more extreme than your example.
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You are wrong. Have a look at FCTM A320:
If you are below vmc there is not ample control available.
ALPHA floor is available, when the flight controls are in NORMAL LAW, from
liftoff to 100 ft R/A at landing. It is inhibited in some cases of engine failureIf you are below vmc there is not ample control available.
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I would be very suprised if this aircraft was in 'Normal Law' at the time of the accident. Lets not forget that in Normal Law there is NO pitch power couple and there are angle of attack protections. Certainly in Alternate law without protections a large power change (Go-arounds) can take a 'normal' airbus pilot by suprise with the resulting large pitch up, often needing a quick and positive nose down input. All pure speculation though and will have to wait for the report.
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@ PBY
I can follow you…
In this light I would like to share some thoughts…
I used to do flight tests on a Dornier 228 to enable the correct rigging of the engines and propellers, so they would produce a resultant forward force as evenly as possible during flight. Especially important in the crucial low speed region. Most critical stages would be during stall recovery and wave off… Flare, speed bleed off, etc…
We went just a little beyond the absolute necessary, as we were testing, as we were relatively high and of course as we were fully aware of what we were doing and as we were very attentive... We knew what could be coming and we would very easily just pull the throttles back as soon as things would go out of hand.
Procedure was to let the speed bleed off to around stall and then very rapidly (slam…) advance the throttles to max. On purpose we would not use rudder and if things would go astray we simply retarded the throttles… And again…: We knew what could be coming…
We would then land, readjust the engines and/or propellers as necessary and then take off again for another try. We would repeat this scenario until the aircraft would fly out precisely straight ahead hands off…
We had the ‘luxury’ to just retard the throttles…
If, unexpectedly (I do not know if this would be possible…) A-Floor would come in asymmetrically, just instinctively pulling the thrust levers to idle in the Airbus won’t work… This is (not very much, but...) in unexpected, surprising circumstances a little more complex.
Of course, keeping it simple and basic here, whilst sitting behind the desk, it is very easy to say: “Just put the thrust levers to toga/max (normal procedure, but may be not in this situation…) and push either red button momentarily and then pull the thrust levers (back) to idle (again)… etc…”
But that is now… And here... At ease… Behind the computor…
@ Carnage Matey!
I can follow you too. But I think an ‘asymmetric spool up’ is different from an ‘unexpected sudden surprise to MAX/TOGA on one side…’
Indeed, all just pure speculation...
In sympathy… Kind regards, learner . . .
I can follow you…
In this light I would like to share some thoughts…
I used to do flight tests on a Dornier 228 to enable the correct rigging of the engines and propellers, so they would produce a resultant forward force as evenly as possible during flight. Especially important in the crucial low speed region. Most critical stages would be during stall recovery and wave off… Flare, speed bleed off, etc…
We went just a little beyond the absolute necessary, as we were testing, as we were relatively high and of course as we were fully aware of what we were doing and as we were very attentive... We knew what could be coming and we would very easily just pull the throttles back as soon as things would go out of hand.
Procedure was to let the speed bleed off to around stall and then very rapidly (slam…) advance the throttles to max. On purpose we would not use rudder and if things would go astray we simply retarded the throttles… And again…: We knew what could be coming…
We would then land, readjust the engines and/or propellers as necessary and then take off again for another try. We would repeat this scenario until the aircraft would fly out precisely straight ahead hands off…
We had the ‘luxury’ to just retard the throttles…
If, unexpectedly (I do not know if this would be possible…) A-Floor would come in asymmetrically, just instinctively pulling the thrust levers to idle in the Airbus won’t work… This is (not very much, but...) in unexpected, surprising circumstances a little more complex.
Of course, keeping it simple and basic here, whilst sitting behind the desk, it is very easy to say: “Just put the thrust levers to toga/max (normal procedure, but may be not in this situation…) and push either red button momentarily and then pull the thrust levers (back) to idle (again)… etc…”
But that is now… And here... At ease… Behind the computor…
@ Carnage Matey!
I can follow you too. But I think an ‘asymmetric spool up’ is different from an ‘unexpected sudden surprise to MAX/TOGA on one side…’
Indeed, all just pure speculation...
In sympathy… Kind regards, learner . . .
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PBY - alpha floor remains operative in normal law with an engine inop until flaps/slats are deployed. Given there's no prior indication of an engine failure it would be interesting to see precisely what triggers the AoA protection to consider an engine failed. In this case with normal law and an assymetrical spool up you'd require one engine to spool up slowly, the system to consider it an engine failure and then drop from normal law straight to direct law (probably the only way to get that sort of pitch up) whilst the aircraft drops below Vmc. Not an impossible chain of events if the landing gear was already down but one would expect some serious ECAM chimes on the CVR to accompany such a sequence.
Here is just a thought:
A double rad alt failure will send the bus straight from normal to direct law when the gear is selected down and the autopilot is disconnected.Approach mode is not available.It helps to fly the approach in manual thrust as well in this case.
The workload can get very busy if you are manoeuvring on base leg,trying to get the FD to capture( because it will not in this case,and you haven't twigged why) and you ask for the gear down - and go straight into direct law and the autopilot disconnects!
A double rad alt failure will send the bus straight from normal to direct law when the gear is selected down and the autopilot is disconnected.Approach mode is not available.It helps to fly the approach in manual thrust as well in this case.
The workload can get very busy if you are manoeuvring on base leg,trying to get the FD to capture( because it will not in this case,and you haven't twigged why) and you ask for the gear down - and go straight into direct law and the autopilot disconnects!
While I am pleased there appears to be progress being made on determining the cause of the crash, is anyone else concerned about the CVR details being released to the media? I know they haven't released exact transcripts, however telling everyone the crew were screaming before impact serves little purpose other than to titillate curious public and media. This is not the purpose of CVRs nor what pilots agreed to when accepting their presence.
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While I am pleased there appears to be progress being made on determining the cause of the crash, is anyone else concerned about the CVR details being released to the media? I know they haven't released exact transcripts, however telling everyone the crew were screaming before impact serves little purpose other than to titillate curious public and media. This is not the purpose of CVRs nor what pilots agreed to when accepting their presence.
Two other notes:
the aircraft was on a DME arc about 16 to 20 NM from touchdown as far as I understand. This is a time when all flight tests should have been done and the gear would not have been extended yet.
Given the Easyjet and Ryanair (BOH) test flight incidents and their possible reason a glance to the XL airways fleet shows only 3 (now 2) A320 and 5 B737. This was probably the first A320 handover flight for the XL crew.