Boeing employees at the red-white-and-blue rally in Everett.

THE COMPETITION TO REPLACE the Air Force’s aging fleet of KC-135 air-to-air refueling tankers has seen two of this country’s biggest defense firms–Northrop Grumman and Boeing–square off for one of the biggest defense contracts in history. The initial contract for 80 aircraft is valued at $40 billion, and the service has plans to purchase as many as 100 more at an as yet undetermined cost. Factor in the high probability that allied air forces will follow the Pentagon’s lead and the numbers add up to maybe as much as $80 billion over the life of the program (the Air Force currently flies 531 KC-135s, all built before 1965), with a final decision from the Pentagon likely to come down at the end of the year.