What happened
During the initial departure climb following takeoff, the pilot experienced an issue where the landing gear would not retract. The pilot subsequently returned to the airport, where a mechanic inspected the gear, serviced the struts, and conducted a retraction test by extending and retracting the gear three consecutive times.
The aircraft later departed on a cross-country flight that included a planned refueling stop. During the approach phase of the second leg, the landing gear failed to extend. The pilot maneuvered the aircraft in the area and attempted emergency gear extension procedures, but the gear would not extend beyond a half-extension position. During the final approach to the runway, the pilot shut down the engine, resulting in the airplane landing short of the runway.
The investigation
An FAA inspector and a mechanic examined the aircraft and determined that the slide tubes on the main gear had accumulated significant dirt, which caused binding during normal operation. This binding was found to consistently cause the electric motor circuit breaker for the gear to pop. While the gear remained stuck during flight, the inspector and mechanic were able to extend the gear manually. At the time of the incident, the aircraft had flown 57 hours since its last annual inspection.