Accident Overview
A Fletcher aircraft operating from a private farm airstrip was destroyed in a sequence of events that began with a low pass over the landing area. The property owner, himself a pilot, had observed the aircraft make a low run to frighten cattle from the airstrip. After briefly losing sight of the airplane, he heard a bang and then saw the aircraft roll to the right until inverted, diving vertically into a hillside and exploding.
Sequence of Events
Ground evidence revealed that the Fletcher's right wingtip struck a 400-pound (180 kg) cow, killing the animal and dislodging the metal wingtip fairing. The fairing, found nearby, had its leading edge crushed. Starting a few meters further, a 46-meter-long scrape mark on the surface was made by the exposed end of the outer wing. The aircraft then collided with the corner of a hangar, the outboard end of the right wing contacting the building about 2.5 meters above ground and 1 meter below the top. This impact caused the separation of the right outer wing panel. The airplane, now out of control, cleared the top of another hangar and adjacent tall trees before diving into a hillside, exploding in flames and breaking up as it tumbled down the slope. The aircraft was destroyed and the pilot was killed.
Investigation Findings
The investigator determined that control was lost upon separation of the outer wing panel due to impact with the hangar. Aileron control had survived the earlier collision with the cow. Factors noted as possibly contributing to the accident included the altitude and azimuth of the morning sun, which may have dazzled the pilot, and the possibility that the aircraft was affected by its own wake turbulence generated during the initial low pass over the airstrip.