Casualties unknown

1987-04-29: Hughes 369D (N10995) — Adriatic Sea — Tamunings

Tamunings, US

On April 29, 1987, a Hughes 369D (registration N10995) operated by Adriatic Sea was involved in an aviation accident near Tamunings. 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 1781061362Data APIEditorial standards

A Hughes 369D helicopter crashed into the Pacific Ocean near Guam after a main rotor blade separated in flight. The aircraft was operated from a fishing vessel and had experienced previous vibration issues.

Accident Overview

A Hughes 369D helicopter, operating from a fishing vessel, lost control and crashed into the Pacific Ocean near Guam. The ship's captain witnessed the accident and reported that one of the main rotor blades separated while the helicopter was orbiting the vessel at approximately 200 feet above mean sea level.

Previous Maintenance Actions

During an earlier flight, a vibration associated with the main rotor system was experienced. The discrepancy was referred to the A&P mechanic on board the fishing vessel, who worked on the helicopter for about one hour alongside the pilot. Following these repairs, the helicopter was test flown.

Rotor Blade Attachment and Corrosion Prevention

The main rotor blades of the Hughes 369D are attached to the main rotor hub using stainless steel retention straps. The manufacturer outlines a procedure designed to help prevent main rotor hub component corrosion on helicopters operated in marine environments. However, records maintained at the helicopter's maintenance base revealed that sufficient supplies were not available to accomplish this procedure on board the ship.

Aircraft Recovery

The aircraft was not recovered from the accident site.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X30734. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.