Casualties unknown

1982-05-04: Hughes 369HS (N9239F) — Ronald M. & Linda S. Warbelow — Tok, AK

Tok, AK, US

On May 4, 1982, a Hughes 369HS (registration N9239F) operated by Ronald M. & Linda S. Warbelow was involved in an aviation accident near Tok, AK. 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 helicopter conducting a sling-load operation on Mount Neuberer experienced engine issues and forward acceleration, leading to a nose-down ground impact. The pilot lacked FAA approval for external load operations.

Accident Overview

A helicopter pilot was conducting a non-revenue sling-load operation on Mount Neuberer, donating services to Tok Community TV, Inc. The operation involved lifting three empty propane bottles from a snow field at an elevation of approximately 5,800 feet. During the lift, the pilot observed the auto relight lamp flash. Almost immediately, the engine-out light and horn activated, and the load may have contacted the ground.

Sequence of Events

Following the engine indications, the helicopter began to accelerate forward despite the pilot's aft cyclic control input. The pilot activated the electric sling release switch, but the helicopter continued accelerating forward and downward. The aircraft struck the ground in a vertical, nose-down attitude while the pilot was applying nearly full aft cyclic. Subsequent examination found the electric sling load latch in the closed position.

Engine Examination

The engine was removed and tested on a test stand. During testing, several hung starts occurred at 45% to 50% until a slight adjustment was made to increase fuel flow. After adjustment, the engine operated well but produced approximately 5% below maximum power.

Pilot Qualifications

The pilot lacked Federal Aviation Administration (FAA) approval for external load operations.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20020917X02635. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.