But although all the divers had been shown photographs of the auxiliary fuel pump, a beer-can-sized unit called a scavenge pump, the part has not been recovered.
22.
We do not believe that the scavenge pump, fuel probes, static electricity, or faulty wiring could create a spark with enough energy to ignite a center wing tank,
23.
Dry sumps also allow for more power because they reduce the amount of windage, oil sloshing up into the rotating assembly, and the vacuum from the scavenge pump improves ring seal.
24.
A scavenge pump that sucks out the last dregs of fuel from the center tank remains a suspect, even though it is designed to avoid introducing a spark; it was never found.
25.
But the scavenge pump, which is used infrequently on the jetliner and normally would not have been on during the 11 minutes the plane was in the air, has not been recovered.
26.
The scavenge pump, a low-capacity pump that empties all but the last few gallons from the center tank, is a suspect in the Flight 800 crash, partly because it was never found.
27.
Engines are both lubricated and cooled by oil that circulates throughout the engine, feeding various inverted engines ( aircraft engine ) it is necessary to employ separate scavenge pumps for each cylinder bank.
28.
Investigators think the third pump, the scavenge pump, is an unlikely culprit since the switches in the cockpit indicate that the pump was off and there is no reason it would have been turned on.
29.
Another example is the oil pan of an aircraft engines are " dry sumped " using scavenge pumps and a swirl tank to separate oil from air, which is also sucked up by the pumps.
30.
Ivor Thomas, a Boeing fuel systems expert, testified that Boeing was testing such an arrestor " even as we speak, " to " provide protection against some strange ignition source in the scavenge pump itself ."
