Originally Posted by
CONF iture
...and a stall could not have happened after clearing the trees as alpha max is not alpha stall.
You clearly didn't read what I wrote, because I said they were comparing it to a *conventionally-controlled* aircraft. Alpha Max is irrelevant in that situation because full back-stick/yoke does not command Alpha Max in a conventional aircraft, it just moves the elevators to the stop - if the aircraft is moving fast enough, it will pitch up and climb, but if it is not, it will pitch up and stall.
Good for you ... what I was expecting is a BEA + Airbus analysis.
By the way if phugoid damping was involved, they could have detailed why Bechet was miraculously spared from it ... ?
As HN39 said, phugoid damping is not used when in pitch command (i.e. the mode Bechet was in), only in HAP mode (which Asseline was in).
As I said before, the fact that the investigation went as far as confirming the behaviour as normal, but no further, could be argued as a point that they missed an opportunity to further explore the mode switches (and consequences of those changes) involved. However, the events of the last three seconds in the context of an accident investigation could equally be considered a minor point when compared to the major systemic failures that led to the aircraft being put in that position. Namely:
- The airline provided woefully inadequate briefing materials
- The airline failed to perform even a cursory review and risk assessment of the flightplan
- The airline failed to check the flightplan against DGAC regs regarding minimum altitude for display flights
- The airline did not require the crew to submit an effective "Plan B" for each stage of the flight plan
- The airline did not require the flight crew to familiarise themselves with the airfield, other than how it appeared on the chart (i.e. no prior recce flight was required)
- Neither the airline nor the flight crew attempted to confirm which runway was in use for the airshow on that day
The result of these failures was that the flight crew were effectively entirely reliant on their ability to improvise at short notice - which, given the inherent riskiness of the manoeuvre, should have been completely unacceptable on the face of it. Even more so when you take into account that there were pax on board.
To the best of my knowledge, "Priority One" of accident investigation is working to ensure that the incident is never repeated.
Now, I'm no accident investigator, but if I were I'd be inclined to consider getting to the bottom of how the aircraft was permitted to get into that position in the first place as a much higher priority than getting too far into why the Alpha Max command was complied with more slowly than it otherwise might have been (especially given the fact that the flight had been woefully mismanaged long before Asseline pulled that stick back).
Put another way, if the mistakes and loopholes in the list above can be prevented and closed, then with all other things considered there should never be another aircraft put in that position again, making the assessment of precisely why the aircraft was slow to achieve Alpha Max somewhat of a moot point.
Again, I said before that Asseline's best hope of being able to get the investigation to look further into the matter of what the EFCS was doing in those last few seconds would have been to take his lumps and remain positively engaged with the investigation throughout. By disengaging from the investigation and subsequently actively briefing against it, he did his own cause more harm than good.