Thanks JET11 for the fuel diagram, very helpful but notable that it does not show the position of the wing tank jettison pump. It is a fair bet that its location and pickup point is close to the fwd and aft boost pumps pickup points.
NSEU I am not suggesting at all that the jettison system can in some way get air into the fuel by surface mixing. What my suggestion is, is that with a jettison nozzle valve open, significant air could be drawn down the jettison manifold by the wing tank boost pump suction and introduced into the pump inlets. ( Provided the non-running jettison pump allowed reverse airflow)
MILT: Why don't you read the AAIB update? The pump damage was either due to a reduction in fuel flow, or fuel aeration, according to AAIB.
SWEDISH STEVE: I was not suggesting, in any way, the centre tank or its pumps are involved. I know that the jettison sytem is not part of the engine supply manifold but if you have one, look in the Boeing tech manual 12.20.07 ( jettison schematic) imagine the jettison valves open and see where air could go if all tank pump inlets are close together. The scenario I suggest is valid with wing tank to engine feed, cross feeds closed and the centre tank empty, with pumps off.
JETDOC: The wing tank boost pumps may very well filter air or vapour, but if a relatively huge amount of air was introduced at the pump inlets, the filter system could be overwhelmed and the result would be loss of fuel flow to the engine HP pumps.
Standing by for more flak, but I am simply suggesting a way that aeration of the fuel supply manifold could occur. I wonder if the AIMS or any recording system notes the jettison valve position, if the system is not activated.