What happened
During the landing phase of flight, the aircraft encountered a ten-knot crosswind condition. The pilot reported losing directional control of the airplane, which resulted in a ground loop. As the aircraft rotated during this loss of control, the left main landing gear collapsed. Subsequently, the left wing struck the runway surface.
The pilot attributed the initial loss of directional control to unequal application of the brakes. It was noted that the airplane was equipped with twenty-nine-inch oversized tires, which may have influenced handling characteristics during the touchdown and rollout.
The investigation
A laboratory examination was conducted on the failed landing gear components. The analysis revealed that the welds on the landing gear had failed prematurely. The failure was determined to be the result of overstress combined with improper welding techniques used during the manufacturing or repair process.
Findings
- Loss of directional control occurred during a crosswind landing, leading to a ground loop.
- Left main landing gear collapse resulted from structural failure of the welds.
- Improper welding techniques contributed to the premature failure of the landing gear under overstress conditions.
- The pilot cited unequal brake application as a factor in the loss of control.