Afghan evacuees left on planes for hours at Dulles International Airport before being cleared for entry

Earlier groups of evacuees have flown to the U.S. on flights operated by the military, but this week, several U.S. carriers, including American, Atlas, Delta, Hawaiian, Omni and United, joined the effort as part of the Department of Defense’s Civil Reserve Air Fleet program. The little-used post-World War II program is using 18 commercial airplanes to aid the military evacuation.