777fly: I agree, a scenario such as you describe could be amongst the plausible possibilities if both left and right engine feed systems had low manifold pressure due to ice contaminated boost pumps (all 4 pumps in the main tanks) and enough vapor trapped near the suction feed bypass valves. Or, if not vapor, leaking connections in both left and right engine feed manifolds, which would reduce suction feed effectiveness with boost pumps failing to deliver. On the other hand, if boost pump pressure dropped due to ice in the pumps, the crew would have been alerted (pressure lights in the pump switches on the overhead panel and the master caution light (including aural alert) would most likely have been presented). No such alerts have been reported by the AAIB. So even if there was no evidence of it after the event, there should have been evidence of it just prior to- and while the event took place, in the form of alerts mentioned above. Green-dot