Event
During approach to the destination airport, the airplane experienced an electrical failure. The pilot reported concern about the potential for an electrical fire and elected not to attempt troubleshooting. He placed the landing gear lever in the "DOWN" position and visually confirmed the gear appeared extended using mirrors affixed to the wings, as the cockpit indicator lights were not illuminated due to the loss of electrical power. The pilot did not use the emergency gear extension system.
Landing
The airplane touched down on the runway with the landing gear appearing extended, but the main landing gear collapsed upon touchdown. The loss of electrical power had rendered the landing gear warning system inoperative; that system is designed to help prevent an inadvertent landing with the gear retracted.
Examination
Postimpact examination of the landing gear and the alternator/battery electrical system found no evidence of any mechanical malfunction. The underlying cause of the electrical system failure could not be determined. Investigators noted that if the pilot had used the emergency gear extension system per the procedures in the pilot's operating handbook, it is probable that the landing gear would have extended and locked.