Good points Glueball:
Were the pumps in certain fuselage tanks in the KC-135 (etc) very similar to any civilian center tank pumps?
The mechanic who recently worked on our plane at a small airport had worked on some -135s at Elmendorf AFB, in Anchorage, Alaska. He told us recently that many years ago, he warned a pilot to keep the fuselage pumps off, unless a little fuel was still indicated on the gauges, to prevent overheating, and when the pilot saw that the mechanic had turned the pump (s) off, the aircraft commander quickly switched the pumps back on. The fact that the mechanic/engineer was enlisted might have been a factor. We know how certain officers will prefer to disregard an experienced enlisted man's advice...
The same pilot later died, along with the rest of his airborne crew (of course) when, as Aircraft Commander (maybe such a decision was made only to demonstrate his authority?), he operated those pump long after the tank was dry, the pumps overheated and exploded debris ignited fumes or whatever else was nearby. I can't remember if he said whether the -135's aircraft "Dash One" pilot manual had cautions or warnings about such pump(s).
This is not to suggest that anything like this happened to the TWA 747. On the contrary, are any of the other allegations, about the FBI, the unusually high level of security for the debris or the missile residue true??
