On December 6, 1997, an Enstrom F-28F (registration N171HH) was involved in an aviation accident near John Day, OR. Investigators recorded the probable cause as: a loss of engine power for undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter pilot experienced rotor droop while maneuvering with a full seed bucket. During a forced landing, the bucket swung forward, causing the helicopter to land on it and overturn. No mechanical failure was found.
Accident Sequence
The pilot was maneuvering with a full seed bucket to the work area when he noticed some rotor droop. He lowered the collective and twisted on more throttle to regain rpm, but the throttle reached its stop with no effect. The pilot initiated a forced landing and reduced forward speed. During the landing, the seed bucket swung forward, and the helicopter landed on top of the bucket. The helicopter bounced twice and came to rest on its left side.
Postaccident Investigation
A postaccident investigation of the engine revealed it was in a condition for a test run. The engine was started and run for five to ten minutes without any noted problems before being shut down. Further inspection of the wreckage did not reveal any evidence of a mechanical failure or malfunction.