Event Summary
A flight instructor reported observing a discharge indication on the aircraft's ammeter during a flight. The crew, which consisted of a pilot undergoing a flight review and her flight instructor, were unable to restore a positive charge indication. Despite this, they elected to continue the flight.
Loss of Electrical Power
As the aircraft approached the airport, it experienced a complete loss of electrical power. The landing gear, which is electrically actuated and retractable, subsequently collapsed upon landing.
Landing Gear Indications
The crew reported that they had observed a gear-down indication prior to the loss of electrical power. However, a witness who observed the aircraft from a vantage point near the approach end of the runway reported that the landing gear was not fully extended during the final approach.
Post-Accident Examination
A post-accident inspection of the aircraft's electrical system revealed a normally functioning alternator. However, when the aircraft battery (nominally 12 volts) was used to energize the system, the bus voltage measured 11.35 volts. Additionally, the alternator drive belt was found to be loose.