Originally Posted by OldBristolFreighter
Surely if this left hand air supply theory is correct then it can only be a matter of time before a cabinful of S.L.F. become incapacitated, if the R.H. system is the same as the L.H.
The BFU report is very specific that:
- technicians who entered the cockpit 15 minutes after the plane had been parked still noticed an unusual smell, distinctive enough to identify it as "definitely not fuel, oil, or electricity, but most likely deicing fluid",
- except for related announcements by the flight crew, the event was not even noticed in the cabin at all.
I don't know if the BFU will take these witness statements about deicing fluid at face value. But it seems to be a fact that the toxic fumes were confined to the cockpit, so understanding how that could be would help to narrow down their possible origin. Frustratingly, the report doesn't even attempt to do so.
I looked at the A319 air conditioning systems manual available at smartcockpit.com, but I don't think I really understand it. For example, it says that when the zone controller primary channel fails: "Pack 1 controls the cockpit temperature. Pack 2 controls the FWD and AFT cabin temperatures." But I can't reconcile that with the general flow chart at the beginning of the document, where it looks like the output of pack 1 and pack 2 is always combined first, before it is distributed to the three air conditioning zones. Oh well.