Casualties unknown

Helicopter Engine Failure Leads to Autorotation and Ground Strike During Sightseeing Flight (N1105B)

Yamhill, OR, US

On July 20, 1997, a Hughes 269C (registration N1105B) was involved in an aviation accident near Yamhill, OR. Investigators recorded the probable cause as: Loss of engine power for undetermined reasons. 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 helicopter experienced an engine power fluctuation and total loss shortly after takeoff during a sightseeing flight. The pilot performed an autorotation, but the helicopter struck the ground and rolled over, resulting in substantial damage.

Accident Overview

A helicopter departed for a sightseeing flight with a pilot and one passenger. Immediately after takeoff, at an altitude of approximately 100 feet above ground level, the engine experienced a power fluctuation followed by a total loss of engine power. Despite the pilot's attempts to restore power, an autorotation landing became necessary. During the landing, the helicopter struck the ground and rolled over, sustaining substantial damage.

Examination Findings

Following the accident, sufficient fuel was found on board the helicopter for engine operation. A detailed examination of both the engine and airframe was conducted, along with a functional test of the engine. The examination revealed no evidence of preimpact mechanical malfunction, and no abnormal operation was observed during the functional test.

Possible Causes

Investigators noted that inadvertent selection of the cyclic governor switch to the off position could affect engine performance during takeoff. Additionally, an improper adjustment of the RPM selector dial could also impact engine operation. However, no conclusive evidence was found to indicate that these specific situations occurred in this case.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001208X08513. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.