What happened
The pilot reported that he was conducting a routine approach to land on a 1700-foot airstrip that he had used frequently. During the final phase of the flight, the pilot stated he experienced difficulty with the approach due to sun glare. He described landing slightly short and below the runway grade.
Upon touchdown, the right main landing gear struck the lip of the runway. The impact caused the right main gear to fail and separate from the wing. This separation resulted in damage to the wing spar. On a subsequent application for a medical certificate dated March 28, 1990, the pilot reported having accumulated 8000 hours of flight time.
The investigation
The physical examination of the aircraft revealed that the right main landing gear had failed and separated from the wing structure. The impact with the runway lip caused significant damage to the wing spar. No other mechanical failures were noted in the provided narrative.
Findings
Contributing factors included the pilot's difficulty with the approach due to sun glare and the decision to land slightly short and below the runway grade on a short airstrip. The collision with the runway lip was the direct cause of the structural failure.