Having had the opportunity to look at the B747 and MD11 stall, and additionally B737 stall behavior, I would be surprised if the spanwise flow of the A330 wing caused any aberrant pitch effects in the stall, and would expect that the aircraft would respond in time to a nose down elevator input if introduced, if the elevator authority has not been reduced by the stabiliser setting. In cruise flight, notwithstanding the use of fuel trimming tanks, the stabiliser setting is NOT a high nose up position. For the B744 (44%MAC, way outside limits...)and B777 (42%MAC) with aft CG, this still is not the case. The washout and engine pylons act to reduce the spanwise flow effect which is otherwise the principle cause of premature tip stalling.
The A310 AFL593 accident was a stall/spin event;
The CAL140 A300-600R event at NGO was due to engine thrust pitch up moment coupling with the nose up trim of the autopilot in opposition to the pilots nose down elevator response.
"* The F/O inadvertently triggered the Go lever. It is considered that the design of the GO lever contributed to it: normal operation of the thrust lever allows the possibility of an inadvertent triggering of the GO lever.
* The crew engaged the APs while GO AROUND mode was still engaged, and continued approach.
* The F/O continued pushing the control wheel in accordance with the CAP's instructions, despite its strong resistive force, in order to continue the approach.
* The movement of the THS conflicted with that of the elevators, causing an abnormal out-of-trim situation.
* There was no warning and recognition function to alert the crew directly and actively to the onset of the abnormal out-of-trim condition.
* The CAP and F/O did not sufficiently understand the FD mode change and the AP override function.
It is considered that unclear descriptions of the AFS (Automatic Flight System) in the FCOM (Flight Crew Operating Manual) prepared by the aircraft manufacturer contributed to this.
* The CAP's judgment of the flight situation while continuing approach was inadequate, control take-over was delayed, and appropriate actions were not taken.
* The Alpha-Floor function was activated; this was incompatible with the abnormal out-of-trim situation, and generated a large pitch-up moment. This narrowed the range of selection for recovery operations and reduced the time allowance for such operations.
* The CAP's and F/O's awareness of the flight conditions, after the PlC took over the controls and during their recovery operation, was inadequate respectively.
* Crew coordination between the CAP and the F/O was inadequate.
* The modification prescribed in Service Bulletin SB A300-22-602 1 had not been incorporated into the aircraft.
* The aircraft manufacturer did not categorise the SB A300-22-6021 as "Mandatory", which would have given it the highest priority. The airworthiness authority of the nation of design and manufacture did not issue promptly an airworthiness directive pertaining to implementation of the above SB."
There was no stall related pitch up...
The CAL676 A300-600R event at TPE was due to an out of trim stabiliser and thrust pitch up moment not being countered by the pilot.
"The investigation team determined that the the following factors combination caused the accident:
1. during all the descent and the approach, the aircraft was higher than the normal path;
2. the crew coordination between the captain and the first officer was inadequate.
3. during 12 seconds, the crew did not counteract the pitch up tendency due to the thrust increase after go around, and then the reaction of the crew was not sufficient.
As a consequence the pitch up increased until the aircraft stalled."
there was no stall related pitch up....
AFL593 pitch was responsive to elevator throughout the upset, even when the aircraft remained in stall and post stall autorotation.
There have been numerous pitch up events with the A310 and A300-600, as well as some with the A320, such as Interflug @ UUEE,
YouTube - Blackbox - 05 - Blaming the Pilot - Part 5 of 5 TAROM at CDG,
http://www.bea.aero/docspa/1994/yr-a...r-a940924a.pdfUSAir @ Washington Reagan. They have invariably been the result of out of trim condition of the stabiliser ("THS" - Airbus...) and rapid pitch up trim related to the application of full TOGA thrust. Numerous of these resulted in aerodynamic stall, none resulted in stall related pitch up.
The A330 has (and it pains me to say so
) a beautifully designed wing. Doesn't look like it but it truly is a great bit of aerodynamics. It is a far better wing than the A300/310/320. The leading edge radius is much larger than any Boeing design, and promotes a gentle aerodynamic stall break.
I have only ever looked at one stall event of an A330, which resulted from an overspeed causing a FCS related uncommanded pitch up which also exceeded max operating altitude of the aircraft, and resulted in a short duration of the aircraft being below VS1g, with varying gz causing short period stall. The recovery was normal, and I cannot recall any evidence of a further uncommanded pitch moment developing. Don't try this at home, but the A330 is a docile handling aircraft. (I remain unconvinced about the justification of having a full rating TOGA setting for day to day go arounds)
This is not Airbus bashing; I have seen B744 events where the crew have ended up in a fairly spectacular unusual attitude through the application of TOGA x2 pushes, and getting full TOGA thrust on a light weight go around. As good as an airshow, and the pax don't have to pay extra!
At altitude, the AFR447 engines would not generate that much thrust, a little over 50% of sea level rated thrust, so the potential for pitch up resulting from thrust couple is reduced, but still exists to an extent.
The touchdown attitude some minutes after the precipitating event does not necessarily bear any direct relation to the initial upset.
regards,
FDR