Airbus crash/training flight

[NigelOnDraft]

CONF

NoD,
I think you’re a bit too eager to blame the crew but don’t realize how during a "normal approach" level at 3000 AGL you could end up 20 knots below your minimum clean speed just because the system did not deem necessary to warn you that maybe something was wrong … isn’t it a matter of concern for you ?

To get a "normal ops" accident we need to mutiply the probablilities of:

1. The maint error leading to double AoA water ingress / freezing.
2. Nobody noticing the speed tape discrepencies / PFR / Check GW messages
3. The aircraft being stalled on a Line Flight

1 is very low P, 3 is also very low P, and in fact in this case just removed the FBW active protections and left it with a "Stall Warning" which worked as design - which is the bottom line in most types.

2 is more interesting, but my best guess would be the anomaly would not last more than 1 or 2 sectors... either by PFR or crew observation.

So my view is that the circs leading to a similar accident in normal Ops is very small, smaller probably that what certification requirements dictate / require of the design. We got an accident, which again should be prevented, since the P of 3 was 1 - the crew deliberately (almost) stalled the aircraft [I cannot recall if it actually did stall].

I think you’re a bit too eager to blame the crew

I have tried to avoid blaming the "crew", but have said I feel the root cause was HF. Some of that HF was the position / task the crew were given / found themselves in. To re-iterate, the basic rules of the test were:

• Flown by a "Test" crew
• Flown above 12,000'
• The Min Speed deduced from the table in the schedule
• The aircraft not flown significantly lower than that Min Speed
• The purpose of the test understood, and the "what if's" briefed

Adhering to (just) one of those factors and no accident.

Bottom line: this was a test to determine if the AoA sensors / systems were working. If you are going to stake your life on the fact that they are working, there is little point in doing the test? All in all, the approach to the test(s) was a box ticking exercise, and if people undertake check/test flying in that manner, it will bite

NoD