Operations in Iraq have been supported by over 30,000 aircraft sorties so far. Most of these were support flights. Some 19 percent were air transports brining in personnel and cargo. Most of these aircraft are C-17s and C-130s. Another 20 percent were refueling sorties, mostly by KC-135 aircraft. The KC-135s tend to fly one sortie a day, refueling 4-6 aircraft while in the air.