Originally Posted by BOAC
I have only seen the AAIB report 6/2001, and would be grateful if you could elaborate on the 'massive overreaction' which according to that report was to close the throttles and disconnect the autothrust, which is pretty much what I would have expected? Perhaps a quote from your report copy would help?
Sure, its not an easy read for someone not acquainted with Airbus peculiarities.
Originally Posted by AAIB
Five seconds after the autopilot disengaged, the thrust levers were closed and then the autothrust was disconnected, probably by the handling pilot in an effort to prevent another overspeed condition.
As thrust levers on FBW Airbi set the thrust limit, closing them commands idle thrust, which is also what you get when you override autothrottle on B and D brands when pulling to idle. Nowadays putting TLs into idle detent also disconnects ATHR but I cannot comment whether this feature was installed at the time of the occurrence. Nevertheless, result was engines trying to spool down to flight idle. Only thing stopping them was activation of alpha floor - you can think of it as automatic low speed protection via autothrust.
Now, I would not expect 0.02 overmach in level flight to be dealt with by closing the TLs shut and keeping them there until high alpha protection kicks in and then watching and doing nothing for 17 seconds as aeroplane pitches up but that's just me.
Originally Posted by GretchenFrage
My quote was not attached to any race or region.
So I see. I am puzzled why in the Welt would you feel my comment to be written in response to your post.
Think of it as pre-emptive non-agression and not reaction.
Originally Posted by Captainplaystation
Clandestino, I was thinking principally of the similar AF A340 "whoopsy" last Summer, where they ended up within (if I remember) about 5 -7(?) kts of the KIAS stalling speed
I am glad to read that, as it strongly indicates you have information regarding the aforementioned AF471 incident that confirm there was:
Originally Posted by captainplaystation
instrument failure/false overspeed indications & uncommanded climb by the "wonder-plane", to counter this
I would appreciate if you share your info with the rest of us. Thank you.
Originally Posted by captplaystation
when I read things like this I maintain an open mind
Very well sir, your open-mindedness will certainly help you appreciate that due to clogging of all three pitots, AF447 slipped into ALT2 law where there is only G protection left. No high sped prot. No alpha prot. No bank prot. Nothing to pitch you up except hitting the -1G, which was never approached.
Originally Posted by Mac the Knife
Would not the attitude indicator(s) have been showing an unusually NU attitude?
Well...yes. They would show attitude not normally met while flying at cruise altitudes, yet they were far from extreme, maximum being +17.9 ANU just before the aeroplane stalled. If the CM2 believed that aeroplane's behaviour and performance were the same at MSL and at FL330, then we are deeply and truly effed.
Originally Posted by GretchenFrage
I simply have to say it again:
It is a puerile reflex to defend any design shortcoming by stating that the "other" design had accidents too!
Grow up, please!
1. The same design has suffered at least 36 times from the failure so similar to the one affecting AF447 it can be considered the same. All other 36 flights continued and landed uneventfully. Therefore, design of the airbus flight controls does not imply accident is inevitable or even probable when all reliable airspeed data is lost.
2. Tu-154, B727 and Q400 were lost when their crews pulled into stall despite the ample warnings. All of them had interconnected yokes installed. Therefore, yokes do not provide absolute protection.
3. Wolfgang Langewiesche in 1944. wrote about pilots that did not understand that pitch flight control does not actually control pitch but rather AoA through elevator and kept pulling into stall until the ground put them out of their misery. Therefore, behaviour of CM2 is not unprecedented and similar cases can be traced as far back as there were three-axis fixed wings.
Care to revise that little statement of yours?
Originally Posted by bubber44
The Airbus computer system algorithm is designed by a bunch of computer nerds who have no understanding of aviation.
Fact that there are thousands of flights safely performed by FBW Airbi every day for last two decades would then to be ascribed to pure luck, eh?
Those who lack capacity, will or both to understand Airbus control system can do far better than ignorantly insult everyone who put their effort into creating pretty fine and functional system.
Originally Posted by A33Zab
IMO there's one common weak link (flaw) in ALL modern A/C design.......and it is called ADIRU!
Airspeed indicators were failing ever since there were first ASIs and ADIRU can not overcome that. Pilots unprepared to deal with their demise in safe manner have no business in aviation, from microlights to 380s.