Casualties unknown

Helicopter Engine Loses Power After Being Serviced with Jet-A Fuel (N7470F)

Saipan, CQ

On March 20, 1989, a Hughes 269C (registration N7470F) was involved in an aviation accident near Saipan, CQ. Investigators recorded the probable cause as: FAILURE OF MAINTENANCE PERSONNEL TO ASSURE THE HELICOPTER WAS SERVICED WITH THE PROPER GRADE OF FUEL. A FACTOR REALATED TO THE ACCIDENT WAS: THE LACK OF A SUITABLE LANDING AREA, WHICH RESULTED IN HAVING TO DITCH THE HELICOPTER IN THE WATER. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A newly purchased piston helicopter, assembled on a dock in Saipan, lost engine power after being serviced with Jet-A fuel. The pilot performed an autorotation to a submerged reef in 3-4 feet of water.

Helicopter Assembly and Fueling

A newly purchased helicopter was transported to Saipan by ship inside a container. After unloading, the pilot, a mechanic, and a mechanic's helper reassembled the helicopter on the dock. The helper was sent to purchase fuel for the helicopter so it could be flown from the dock to the company base at the airport. The company had previously operated only turbine-powered helicopters; this was its first piston-powered model. The helper went to a fuel facility and bought 10 gallons of Jet-A fuel, which he used to service the helicopter.

Flight and Engine Failure

The pilot started the helicopter, performed a run-up, and took off for a 3-mile flight to the airport. However, the engine lost power during the flight. The pilot executed an autorotation and landed on a submerged reef in about 3 to 4 feet of water.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X27922. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.