Incident Summary
A pilot reported that while approaching the destination airport, he extended the wing flaps and lowered the landing gear, observing three green gear lights. The airplane floated over the 3,640-foot-long runway and initially touched down approximately 800 to 900 feet beyond the threshold. Shortly after touchdown, the right main landing gear partially retracted. The right wing then contacted the runway surface, and the airplane veered off the runway into a ditch.
Investigation Findings
During the examination of the wreckage, the wing flaps were found in the retracted position, and the landing gear system functioned normally when tested. The physical evidence indicated that during the rollout, the landing gear motor was activated while some weight was on the left main landing gear. This activation resulted in a bending of the left gear actuator arm and the partial retraction of the right main gear. The flaps showed evidence of ground impact damage and were in the retracted position.
Physical Evidence
The investigation determined that the landing gear motor operation under load caused the bending of the left gear actuator arm. The partial retraction of the right gear occurred because of the motor's activation while the aircraft still had weight on the left gear. The flap position, as found, was consistent with impact damage from the ground contact, but no pre-impact malfunction was noted.