Originally Posted by
CONF iture
but what you confirm here is that the phugoid damping (if it is actually the guy behind the restriction ...) was useless and detrimental performance wise.
Not quite - as OG says:
Originally Posted by
Owain Glyndwr
The “job” the EFCS was being asked to do has been stated as “Provide the commanded alphamax”, but ... [that] is in fact simplistic. A more accurate task description would be “Provide the commanded alphamax in a controlled manner so as to minimise the risk and potential magnitude of overshoots above alphamax”
This is because it's an airliner, not a fighter - HAP mode is designed to maintain stability and trajectory, and Alpha Max is the upper AoA limit of that mode - it is *not* necessarily for use as an escape manoeuvre. In fact it can only really be expected to perform that function in concert with either sufficient airspeed, sufficient manual thrust applied (and available) or with Alpha Floor enabled. Asseline set the situation up so as to have neither.
Bechet did much better without it than Asseline with it.
As the graphs demonstrate (and OG has helped describe), Bechet initially got to a higher AoA in less time, but the overall performance was more or less similar. Whichever way you slice it, the fundamental aspect that cannot be ignored is that, possibly as a result of task saturation, Asseline did not recognise the danger in time and therefore did not act swiftly and decisively enough. That in itself is not the main reason he shoulders the responsibility he does - it's more to do with his decisions prior to then, when he had ample opportunity to turn around and do the run with more margin for error - but instead elected to press on and continue improvising with an ever-narrowing safety margin.
Airbus's own Alpha Max demonstrations were performed with sufficient thrust to achieve and maintain Alpha Max while preserving trajectory, and they were properly prepared such that they had a clear path ahead of the aircraft while in that state, because in that mode and at higher alphas, the room for evasive manoeuvre is significantly reduced.