And United has been hit especially hard because many of its pilots, protesting the pace of labor negotiations for a new contract, refuse to work overtime on their days off, forcing the airline to fly less even as demand rises. By far, the biggest problem has been the weather. In June, one of the worst months in aviation history for thunderstorms, weather accounted for 79 percent of all aviation delays. The Federal Aviation Administration was forced to institute special air traffic programs to deal with severe weather in the Northeast on 19 days, compared with five days in June 1999. But weather wasn't the only reason for delays.
Planes have mechanical problems.
And after years of mistakes and mismanagement, the air traffic control system is straining to handle the amount of traffic that airlines want to offer. After last year's problems, the FAA and the airlines set up a cooperative program to manage delays, efforts that were credited with preventing a bad situation from becoming worse. The FAA and the airlines agree early in the day about how they will handle bad weather, runway closings and other problems that cause delays. Avoiding decisions at the last minute allows them to cancel or delay flights in a more orderly fashion. Early Intervention At O'Hare last Monday, things hardly seemed orderly, at least to passengers.