Amateur-built RV-9A N70720 accident near Oregon City, Oregon

Probable cause

The pilot's decision to depart with known mechanical anomalies and the loss of engine power for undetermined reasons.

NTSB analysis

The engine had recently been operating erratically and the day before the accident it lost power while the pilot was taxiing. Following numerous failed attempts to restart the engine, it eventually started and began to emit flames from the inlet port and a fire extinguisher was used to suppress the fire. The day of the accident, and after cleaning the residue left from the extinguishing agent, the pilot started the engine, performed a runup and then departed to fly the airplane back to his home airport. A short time after takeoff, the airplane was observed by witnesses to be maneuvering at a low altitude adjacent to a highway as if attempting to land on the road. The engine experienced a loss of engine power and the airplane collided with trees and powerlines during a forced landing; the airplane came to rest inverted and was partially consumed by a post crash fire. A postaccident inspection revealed that the extensive fire damage precluded testing the integrity of the fuel system. Numerous fittings and controls on the engine were loose or very low torque, most likely due to thermal damage from the post crash fire. The examination did not show any evidence of preimpact mechanical malfunction or abnormalities, although the damage was too extensive to definitively determine the reason for the loss of power.

Text from the NTSB. Open the NTSB docket for WPR10LA366 for the full record.