2 fatalities

Two Aircraft Collide During US Navy Exercise, Four Killed (N39DM)

San Clemente Island NAS, United States of AmericaFlight

On March 5, 1986, a Learjet 35 (registration N39DM) 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

A mid-air collision occurred during a military exercise off San Clemente Island, involving a Learjet 24D and another aircraft. All four crew members were killed. The cause of the collision is unknown.

Incident Details

The accident occurred during a military exercise that involved a simulated aerial attack on a United States Navy vessel. Two aircraft were participating in the exercise when, under unknown circumstances, they collided in flight. One of the aircraft was a Flight International Learjet 24D bearing registration N97DM. The type and registration of the other aircraft were not disclosed in the official report.

Location and Aftermath

The collision took place over the Pacific Ocean, approximately 27 miles southeast of San Clemente Island, California. Following the collision, both aircraft descended uncontrolled and impacted the water. All four individuals on board—two crew members per aircraft—were killed in the accident. The wreckage sank into the sea.

Probable Cause

The official investigation into the accident determined the probable cause to be an in-flight collision for unknown reasons. No further causal factors were identified.