Casualties unknown

1983-07-03: Bell 47G-2 (N2495B) — Bethany, OK

Bethany, OK, US

On July 3, 1983, a Bell 47G-2 (registration N2495B) was involved in an aviation accident near Bethany, OK. Investigators recorded the probable cause as: Oil depletion leading to engine failure. 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 collided with trees and rolled over during a forced landing after an engine failure. The engine had a history of high oil consumption and was found empty post-accident with signs of oil depletion.

Accident Overview

A helicopter experienced an engine failure and subsequently collided with trees, rolling over during a forced landing. The pilot had been conducting sightseeing flights with passengers for several hours prior to the accident. After the final flight, the pilot and his wife departed a city park to return to the aircraft's home base. Approximately two miles into the flight, the engine failed.

Forced Landing Attempt

Due to strong winds, the pilot was unable to reach a vacant school yard and was forced to land in an area with trees, resulting in the collision and rollover.

Engine History and Oil Consumption

The aircraft engine had a known history of oil consumption, using about one quart of oil per hour. The pilot stated that he had flown for over an hour since last checking the oil level. Following the accident, the engine oil tank was inspected. It was found empty, with no damage to the tank and no evidence of leakage.

Findings

Examination of the engine revealed damage consistent with extreme overheating. The manner of the engine failure was representative of an oil depletion failure.

Probable cause

Oil depletion leading to engine failure.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X43726. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.