NTSB Factual Report

On December 26, 2001, about 1510 Pacific standard time, an Aeronca 7AC, N83136, impacted mountainous terrain near Winters, California. The unoccupied airplane was destroyed, and there were no injuries. The airplane took off with no one aboard when the private pilot started the engine from outside the airplane by pulling the propeller. Visual meteorological conditions prevailed for the personal flight operated by the owner under 14 CFR Part 91. The airplane departed from a private airstrip near Petaluma, California, at 1545, and the pilot's intent was to land at Gnoss Field at Novato, California. No flight plan was filed.

According to a spokesman for the owner/pilot, the aircraft was not equipped with an electric starter motor and the pilot normally and routinely started it by "propping" (pulling the propeller by hand). The pilot (who was alone) stood behind the propeller when pulling on it.

The pilot reported that, after "propping" the engine about 4 times without achieving engine start, he perceived the engine was "flooded" and returned to the cockpit where he turned the magneto switch "off" and advanced the throttle to the full throttle position. He then turned the engine backwards 10 revolutions. He next returned to the cockpit again and turned the magneto switch back to the "both" position; however, he forgot to retard the throttle back to the idle position. When he next "propped" the engine it started at maximum power. The pilot attempted to restrain the airplane but was unable to do so and the airplane moved forward and took off with no one aboard.

The airplane was located the following morning about 45 miles northeast of the departure point, having crashed in mountainous terrain near Lake Berryessa.

NTSB Probable Cause

The failure of the pilot to retard the engine throttle to idle while hand-propping the engine, which resulted in the engine starting at full (takeoff) power and the airplane taking off with no one aboard.