Accident Overview
On September 8, 2012, at approximately 1330 Pacific daylight time, a Great Lakes 2T-1A-2 biplane, registration N3702F, experienced a loss of engine power while maneuvering. The pilot performed a forced landing in an open field near Monroe, Washington. The airplane was substantially damaged, but neither the pilot/owner nor the certified flight instructor (CFI) onboard sustained injuries. The flight operated under 14 Code of Federal Regulations Part 91 as a local area aerobatics instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed. The aircraft had departed Harvey Field Airport (S43) in Snohomish, Washington, about 1245.
Flight Sequence
According to the pilot/owner, the purpose of the flight was to improve his aerobatic skills. After spending a couple of hours on the ground reviewing maneuvers with the CFI, they boarded the airplane with the CFI in the front seat and the pilot in the rear. Start-up, taxi, and run-up were normal. They departed to the north and flew to a valley between Monroe and Duvall, where they conducted a series of aerobatic maneuvers including advanced stalls, slow flight, aileron rolls, and inverted emergency roll recovery procedures. After completing the aerobatics, they headed back toward S43. The pilot reported that the airplane did not feel right, and shortly thereafter the engine began losing power. He adjusted the mixture and throttle without effect. The engine then quit, and he asked the CFI to fly while he attempted to restart it unsuccessfully.
The CFI's written statement corroborated the sequence. After about 40 minutes of flying, they began the return to S43. In level cruise flight, the engine showed signs of power loss. The pilots decided to continue toward S43 while remaining over open fields. When the pilot could not restore full power, he asked the CFI to take control. The CFI established best glide speed and identified a plowed field for the forced landing. The CFI reported the airplane was at 3,000 feet when the engine stopped.
Forced Landing and Ground Impact
The CFI executed a successful three-point landing. During the rollout on the soft dirt, the main landing gear sank into the freshly plowed field, causing the airplane to nose over onto its back. This resulted in structural damage to the rudder and vertical stabilizer.
Post-Accident Examination
A Federal Aviation Administration (FAA) inspector examined the engine along with maintenance personnel. The report is part of the public docket. Visual examination revealed no obvious damage; engine controls moved freely to their stops with no binding. The exhaust and induction systems showed no blockages. Fuel sampled from the header tank quick drains appeared and smelled like 100 low-lead aviation fuel, with no contaminants noted. An engine run was performed, and the engine operated normally with no mechanical anomalies.