On July 8, 2000, a Schweizer G-164B (registration N3629T) operated by Paynes Flying Service, Inc. was involved in an aviation accident near Moscow, TX. Investigators recorded the probable cause as: The failure of the turboprop engine's power output reduction gear to the propeller, which resulted in a total loss of engine power. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A turboprop aircraft suffered total engine failure during a crop dusting run due to a reduced gear failure, resulting in a forced landing where the left wing struck a tree.
What happened
The incident occurred while the pilot was conducting an agricultural application flight, specifically a swath run to fertilize trees. During this operation, the pilot reported hearing a loud noise described as a scream, which was immediately followed by a complete loss of engine power. In response to the emergency, the pilot initiated a forced landing procedure. As part of this process, the aircraft dumped its load of fertilizer. During the approach and impact phase of the forced landing, the left wing of the airplane struck a tree before the aircraft subsequently impacted the ground.
The investigation
Following the accident, a detailed teardown examination was conducted on the turboprop engine involved in the incident. This mechanical analysis focused on identifying the root cause of the sudden power loss. The inspection revealed that the reduced gear connecting the engine to the propeller had failed. This mechanical failure is consistent with the reported total loss of power experienced by the pilot during the agricultural operation.
Findings
The investigation determined that the primary factor leading to the accident was the mechanical failure of the engine's power output reduction gear. This component failure resulted in the immediate cessation of propeller rotation and engine power. The subsequent collision with a tree during the forced landing was a direct consequence of the inability to maintain controlled flight following this catastrophic mechanical event.
Probable cause
The failure of the turboprop engine's power output reduction gear to the propeller, which resulted in a total loss of engine power.