Incident Description
About 30 minutes after departure, electrical equipment began to fail. The pilot turned off the alternator and reset it, but the issue persisted. Switching to the #1 regulator did not correct the problem. While turning onto the downwind leg, the pilot moved the landing gear handle to the down position, which resulted in a complete loss of electrical power. The pilot then manually cranked the landing gear down until he met resistance, but he did not note the number of revolutions. The aircraft subsequently touched down with the landing gear only partially extended.
Post-Incident Examination
After landing, both batteries were found to be dry. The left alternator produced no output, and the right alternator's current limiter was burned open. During a subsequent interview, the pilot stated that he did not turn off any electrical equipment during the flight. He also indicated that he had not practiced the emergency landing gear extension procedure in flight prior to this occurrence.
Summary of Pilot Actions
The pilot attempted to address the electrical failure by turning off and resetting the alternator and switching to the alternate regulator. He then manually extended the landing gear when power was lost, but he did not track the number of turns. The pilot did not reduce the electrical load by deactivating non-essential systems.