NTSB Factual Report

The pilot reported that he and the passenger, who was the owner of the airplane, were going for a local flight. The airplane was powered by an 85 horsepower engine and manufactured in 1946. Approximately 0.5-miles from their departure airport, the airplane suddenly began to sink so the pilot turned the airplane into the wind. The airplane began to climb and then encountered downdrafts and an excessive sink rate developed. The pilot was unable to maintain altitude and force-landed the airplane in a gravel quarry. During the forced landing, the airplane sustained substantial damage to the wings and fuselage. The temperature at the time was approximately 95 degrees Fahrenheit.

NTSB Probable Cause

The pilot's inadequate weather evaluation which resulted in the airplane's lack of climb performance and subsequent collision with terrain. Contributing factors included the downdraft and the high temperature.