Thorp T-18 — Kent, WA

What happened

The pilot had recently installed an overhauled carburetor and new air inlet on the airplane. Because the airplane had not been flown for about nine months, the pilot drained all of the old fuel out of the airplane and refueled it. Witnesses reported that the pilot performed an extensive engine run up that lasted 10 to 15 minutes, and with satisfactory results, the pilot decided to take the airplane around the airport traffic pattern. A witness based at the airport said that during the initial takeoff, the engine sound was smooth. As it continued, the witness heard the engine running rough. When the airplane flew past the witness about 300 feet above the runway, the witness saw two puffs of white smoke. The airplane appeared to have adequate airspeed and it was still climbing, although the engine was cutting out. The engine then cut out completely and the airplane continued straight ahead for about 1 second. The airplane entered a slow turn to the right, and when it had turned approximately 160 degrees, the right wing stalled and the airplane rolled into a spin. The airplane went out of view of the witness in a nose-down attitude of approximately 70 degrees. A friend of the pilot who was based at the airport said that when departing to the north as the pilot had done, there are limited options available for emergency landings. The fuel valve was found in the closed, or "off", position. Based on the length of the engine run up, the fuel selector was undoubtedly positioned correctly at takeoff and was most likely moved to the closed position by the pilot when he determined that a forced landing was inevitable. Post accident examination of the wreckage did not disclose any pre-impact mechanical anomalies. Due to damage sustained to the carburetor, no functional testing could be performed.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.