Incident Overview
On a routine flight from Sacramento to San Diego with an intermediate stop in Los Angeles, PSA Flight 182 was descending toward San Diego-Lindbergh Field runway 27. The crew was notified of a Cessna 172M, registration N7711G, operated by Gibbs Flight Center, which had just departed San Diego Airport for a local training mission with one student pilot and one instructor on board.
At 0901:47, at an altitude of 2,600 feet and 3 nautical miles northeast of San Diego Airport, the two aircraft collided. Both airplanes went out of control and crashed into several houses and the 805 highway, located between the districts of Altadena and City Heights. The impact disintegrated both aircraft. All 137 occupants on both aircraft were killed, as were seven people on the ground. Nine other individuals on the ground sustained serious injuries, and dozens of houses were destroyed.
Probable Cause
The official investigation found the probable cause to be: "The failure of the flight crew of Flight 182 to comply with the provisions of a maintain-visual-separation clearance, including the requirement to inform the controller when visual contact was lost; and the air traffic control procedures in effect which authorized the controllers to use visual separation procedures in a terminal area environment when the capability was available to provide either lateral or vertical separation to either aircraft." Contributing factors included: the failure of the controller to advise Flight 182 of the direction of movement of the Cessna; the failure of the pilot of the Cessna to maintain his assigned heading; and the improper resolution by the controller of the conflict alert.