WASHINGTON (AP) - The Federal Aviation Administration is requiring about 3,500 Boeing jets to fly with extra fuel to prevent fuel pumps from overheating and possibly causing an explosion. The FAA has sent airlines three safety warnings about the problem since August. The latest was issued last weekend after pumps in three planes overheated, the FAA said Tuesday. The warning is intended as a precaution while the FAA figures out what's causing the problem with the pumps, made by Hydro-Aire Inc. of Burbank, Calif. James McKenna, managing editor of Aviation Maintenance magazine, said the FAA doesn't ordinarily need to make...