Incident Overview
A pilot reported that during the landing approach, the landing gear was extended and a safe gear-down indication was obtained. The approach was made with the flaps retracted. The pilot did not hear the gear warning horn. After touchdown, the aircraft rolled approximately 1,500 feet with all three landing gears on the surface. The right wing was then observed and felt to drop until the right propeller made contact with the runway.
Witness Observations
A mechanic employed by a fixed-base operator observed the landing. He noted that the approach was stable, the landing gear was down, and the flaps were up. After touchdown, the aircraft began its rollout, then "hopped a little, like he pulled back." The mechanic stated that the "doors closed, looked like gear went up and locked, went down and slid on its belly."
Post-Accident Examination
An FAA inspector examined the aircraft. The landing gear handle was found in the down position, the flaps were up, and no circuit breakers were found to be popped. Damage was discovered in the landing gear extension/retraction system, but no preimpact failure was found.
Conclusion
The investigation did not establish a probable cause for the event. The sequence of events suggests the landing gear may have retracted momentarily after touchdown, causing the right wing to drop and the propeller to strike the runway, but the exact mechanism remains undetermined.