Lyman:
5. Loss of dedicated cooling to the avionics. A lot of stacks of heat producing equipment. If I was a smartie, I might exhaust the heated cooling air from the avionics bay into the cockpit environment? Might that explain the smell?
Lyman, have you taken a look at where the avionics are located in an A330? I refer to the heat producing items.
Might be easy to check, it could be entirely off base... If a fan motor went tu, could it produce the noise referenced by BEA as "increased cockpit noise" (unidentified)?
A fan motor might, but which one are you referring to? A vent fan?
Long ago, I reminded myself that a return up the aisle to his (Captain Dubois) office would be seriously "uphill"... Quite a climb actually...About four times as steep as he may have "expected". He walked into three seconds of STALL WARN, so combined with the uphill climb and the chirp of STALL: "hey knucklehead, get the nose down, you looking for a swim
Lyman, even with an uphill walk, Captain Dubois did not have an altimeter at his rest seat. He has no way to know the altitude and airspeed of the aircraft until he enters the cockpit, even though I think by this time the engines have been at TOGA (and perhaps back to idle before he returns? don't have the time line in front of me) so his aural cues might be a red herring as he heads up toward the cockpit to find out why Robert has summoned him.
He enters, and may or may not see an airspeed that makes sense to him. I am not sure if speed indications were valid or not at that point. If they were, and he's already stalled, they'd not be at values that would make any sense to a man who left the cockpit at Mach 0.82 in straight and level flight. He's got to play catch up immediately. Sadly the man who summons him is not recorded as providing a concise situation brief of "our story so far" in the cockpit.
I get the idea that Captain Dubois enters, and looks at various instruments.
He sees an airspeed value that makes no sense.
He then look at the back up instruments that are more or less in the center of the display area, and again sees an airspeed value that makes no immediate sense. (Perhaps this explains his "this is not possible" remark).
His pilot in the Right Hand Seat, Bonin, is explaining that he hasn't got control of the aircraft, that his speeds are all wrong, but I never get the impression that he gets across to Captain Dubois just what is wrong. (Since he doesn't seem to know that he's stalled, that is no surprise ...)
Dubois has to establish an instrument scan (while not sitting in his usual seat, and with airspeed indications that may or may not be reliable, and most likely are values that he finds strange) and talk the flying pilot back into flying the aircraft. (See my points to jc up there a few). He has to, since Bonin is obviously having trouble with that.
While Captain Dubois' instincts seem to be right, his situational awareness isn't matched with his situation. (I may be hanging on the "not possible" thing far too thoroughly here). He has to piece together what his airspeed, Rate of Descent, and Altitude inputs mean all while being told that there is something wrong with the aircraft by the guy at the controls.
In other words, I belive he has no idea if the crew had descended and was climbing back up as he walks to the cockpit, or if the rumbling and turb he feels is from ITCZ weather, other turbulence, or what, but I don't think his brain is associating "buffet and turbulence" with "stall." At least not initially.
He has a lot to soak up and may not actually have been utterly focused on the walk up, other than thinking
"What's wrong that Robert has called me?"
and only really gets the brain in gear as he look at the displays and has to overcome the
WTF???
reflex.
I work under the assumption that Captain Dubois had no idea that things were AFU as he walked up the aisle to the cockpit. He had left the aircraft straight and level. He MAY have assumed that he was being called forward due to increase in turbulence. (Buffet mistaken as turbulence by a pilot who'd not been in an actual A330 stall buffet, eh?) (See notes about cabin crew reports to the cockpit).
That's my take on it, and I may be waaaaaaaaaaay out to lunch.