1 fatality

US Navy Training Aircraft Crashes into Ocean; Pilot Killed (N701DM)

San Diego, United States of AmericaFlight

On February 28, 1989, a Mitsubishi MU-2 Marquise (registration N701DM) operated by Flight International was involved in an aviation accident near San Diego, United States of America in flight. One person was killed. Investigators recorded the probable cause as: Pilot incapacitation for an unknown reason. 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 US Navy aircraft, FNT701, crashed into the ocean after a training mission. The pilot was killed. Investigations cite pilot incapacitation as the probable cause.

Incident Overview

A US Navy aircraft, designated FNT701, crashed into the ocean while returning from an airborne intercept training mission. The flight, conducted in support of US Navy training, had just completed its mission, and FNT701 was returning home alongside another aircraft, FNT492, when the accident occurred.

Flight Path and Descent

Radar data revealed that FNT701 was cruising at 22,700 feet before descending slightly to 22,500 feet. The aircraft maintained this altitude for approximately 2 minutes and 37 seconds. It then initiated a descent that ultimately led to impact with the ocean. The rate of descent initially measured about 5,000 feet per minute and increased to 19,000 feet per minute.

Communication and Observations

No distress calls were transmitted from FNT701. However, two transmissions lasting approximately 30 seconds in total were recorded. These transmissions contained no voice communication; only an open microphone and the sound of the propeller(s) were audible. During the first transmission, the word "oh" could be heard.

FNT492, the accompanying aircraft, observed FNT701 descending below cloud cover but detected no distress signals from the aircraft.

Recovery and Pilot

Search and rescue operations recovered little wreckage. The pilot, who was the sole occupant on board, was killed in the accident.

Probable Cause

The official investigation determined that the probable cause of the accident was pilot incapacitation for an unknown reason.