What happened
Upon arriving at the airport, the pilot found that the aircraft's battery was weak. To start the engine, the pilot requested an electrical boost from a local mechanic. After successfully starting the engine, the pilot allowed it to run for several minutes before taxiing to the runway for takeoff. The pilot reported that the pre-takeoff runup procedure was normal. During this process, the pilot turned off all electrical equipment except for one communication radio.
After liftoff, the pilot discovered that the landing gear would not retract completely. The pilot elected to continue the flight. While en route, an attempt was made to manually lower the main landing gear; however, after feeling pressure on the emergency extension handle, the pilot decided to discontinue the extension operation.
During the landing roll at the destination airport, the right main landing gear collapsed, causing the aircraft to veer off the right side of the runway. During the subsequent wreckage recovery phase, as the right wing was lifted, the pilot used the emergency extension handle to lower the right main gear.
The investigation
An examination of the electrical system revealed that a diode in the alternator had slipped from its normally installed position.