Mariposa-Yosemite Airport
Aircraft Accident/Incident Report

Mariposa, California 95398
Tuesady, September 14, 1999 18:10 PDT

Following a local area flight the amateur-built airplane returned to the departure airport and entered the traffic pattern. Following a touch-and-go landing, the airplane climbed to about 200 feet agl over the departure end of the runway and made an abrupt right roll to nearly a 90-degree bank angle. It then turned to a northerly heading, and, as it turned, descended in a wings vertical attitude into terrain near the runway end. Three persons reported they had seen the pilot perform the steep right turn departure maneuver on previous occasions. One witness reported that the engine was operating smoothly during the touch-and-go and until impact; a second reported the engine was operating smoothly during the touch-and-go but did not recall the engine sound during the descent to impact; and a third witness reported that the engine 'sputtered' during the climb and descent to impact. The aircraft impacted in a steep nose down attitude. There was fuel spilling from the aircraft and the aircraft's flight controls were continuous at the accident site. No heavy aircraft were reported to have preceded the aircraft on the departure runway.

The pilot's failure to maintain an adequate airspeed margin while performing an intentional steep right bank turning maneuver, which resulted in a stall/mush and descent into terrain.