TLB;
Originally Posted by TLB @ 29th May 2011 15:44
Originally Posted by JD-EE
TLB - TO/GA was not asserted until the second stall warning. At about the time of the first stall warning, perhaps before it upon AP/AT disconnect, the PF simply raised the nose a little and left the CLB default throttle setting.
JD-EE,
Thanks. But this is exactly the point I am trying to raise. If the PF initially thought his main problem was an unreliable airspeed situation, then his initial response (raised the nose a little and left the CLB default throttle setting - your words) was exactly the right thing to do, according to the C/L.
With respect
TLB, no, this is
not "exactly the right thing to do" for an Unreliable Airspeed event in cruise.
Please reference
post #2269, and the First BEA Interim Report, Page 69 and Appendix 7.
The UAS drill has two sections - the memorized items are to be executed when the safety of the flight is at immediate risk, which is primarily at and just after takeoff, (as the Birgenair and Aeroperu accidents demonstrate). When to apply the memorized items is stated in the expanded training documents for the A330 and so should be no mystery to those who know their stuff. It's how drills and checklists are run.
After the qualifying conditional, (is the flight at immediate risk, yes/no), and the AP/AT are disengaged etc, there are the three conditional statements which refer to the A330 acceleration altitudes, stating pitch and thrust settings which provide an immediate "safe zone" until the aircraft is at a suitable altitude.
The qualifying conditional statement at the bottom of the memorized drill,
is actually the second statement in this drill IF the flight is not in immediate danger.
The statement requires that the aircraft be leveled off for troubleshooting. Troubleshooting means, while stabilizing the aircraft (essentially "doing nothing"), getting out the QRH for the pitch and power settings for the weight and altitude, (in this case, FL350), and then calling for the "ECAM Actions" when the aircraft flight path is stabilized.
This guidance is in a number of Flight Crew Training Manuals and has been the SOP for a UAS event since around 2005, perhaps earlier.
Whether the pitch-up is this particular response, or a response which is entirely unrelated to the UAS event remains to be determined and we cannot determine this with the information we have. But there are documents cited here which tell us that such a response was a concern. As I have said a number of times when discussing this scenario, one way or another, it needs to be confirmed or dismissed as part of the overall investigation as to why such a response was executed.
mm43;
I know that you will know this but, for the benefit of those who don't, the ACARS messages do not capture any information about a stall, nor the associated warnings or indications, just as the CMC does not record Overspeed warnings. It is, after all, a
maintenance system, not a diagnostic flight data tool as some have tried to make it.