Casualties unknown

1988-05-17: Hughes 369E (N5258C) — W I D Industries, Inc. — Chemult, OR

Chemult, OR, US

On May 17, 1988, a Hughes 369E (registration N5258C) operated by W I D Industries, Inc. was involved in an aviation accident near Chemult, OR. Investigators recorded the probable cause as: The pilot's failure to maintain visual reference with the ground during takeoff due to dust and debris stirred up by the main rotor, which resulted in the helicopter striking a tree. 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 struck a tree shortly after takeoff from a road surface, resulting in a rollover to the left side due to loss of visual reference and high density altitude conditions.

What happened

The pilot was attempting to initiate takeoff from a road surface under challenging atmospheric conditions. The environment presented a density altitude of 6,300 feet, significantly reducing aircraft performance capabilities. Additionally, the helicopter was being operated in close proximity to its maximum gross weight limitation, further compounding the difficulty of achieving safe lift.

Approximately 150 feet from the initial point of takeoff, the helicopter's main rotor system engaged with the ground surface. This action stirred up a substantial amount of dust and debris from the road. The resulting particulate cloud rapidly obscured the pilot's visual reference to the ground. Without adequate external visual cues to maintain orientation and altitude awareness, the pilot lost control of the aircraft's trajectory.

The helicopter subsequently descended into a tree. Upon impact with the vegetation, the main rotor blade struck the tree trunk or branches. The force of this collision caused the helicopter to roll violently to its left side, bringing the flight to an abrupt end on the ground.

Findings

Several critical factors contributed to the accident sequence. The high density altitude reduced the available lift and engine power, making it difficult for the aircraft to climb effectively while near its weight limits. The operation from a road surface created a significant hazard through rotor wash-induced dust clouds. This loss of visual reference is a well-documented risk in helicopter operations, particularly during low-level maneuvers or takeoffs from unprepared surfaces.

The combination of reduced performance margins due to weight and altitude, coupled with the immediate loss of situational awareness caused by debris ingestion into the pilot's field of view, led directly to the loss of control and subsequent impact with the tree.

Probable cause

The pilot's failure to maintain visual reference with the ground during takeoff due to dust and debris stirred up by the main rotor, which resulted in the helicopter striking a tree. Contributing factors were the high density altitude and operation near the maximum gross weight limitation.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X25825. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.