The U.S. commercial aviation system is safe despite reports of increasing numbers of near mid-air collisions, the head of the Federal Aviation Administration said. "There are too many airplanes for the facilities available at which to land, and we do need more airports," Donald D. Engen said on ABC's "This Week With David Brinkley." However, Jim Burnett, chairman of the National Transportation Safety Board, blasted the FAA for refusing to limit the number of flights in rush hours. Appearing on CBS's "Face the Nation," Burnett said: "I want to make very clear I think . . . at this time there is cause for alarm."