2 fatalities

Two Aircraft Collide During Military Exercise, Four Killed (N97DM)

San Clemente Island NAS, United States of AmericaFlight

On March 5, 1986, a Learjet 24 (registration N97DM) operated by Flight International was involved in an aviation accident near San Clemente Island NAS, United States of America in flight. 2 people were killed. Investigators recorded the probable cause as: In-flight collision for unknown reasons. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 6 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-11Data APIEditorial standards

Two aircraft collided during a military exercise involving an aerial attack on a US Navy vessel. The collision occurred about 27 miles southeast of San Clemente Island, killing all four crew members.

Accident

Two aircraft were involved in a mid-air collision during a military exercise that simulated an aerial attack on a US Navy vessel. One aircraft, whose type was not specified, carried two crew members. The second aircraft was a Flight International Learjet 35, registered N39DM, also with two crew on board. Under unknown circumstances, the two aircraft collided. Following the collision, both aircraft crashed into the sea approximately 27 miles southeast of San Clemente Island. All four crew members were killed in the accident.

Investigation

The official investigation concluded that the accident was an in-flight collision for unknown reasons. No further details regarding the specific sequence of events, communications, or maneuvers leading to the collision were provided. The investigation did not identify any additional causal factors.

Probable cause

In-flight collision for unknown reasons.