What happened
During a flight intended for a flight review, the crew—consisting of a pilot and a flight instructor—noted a discharge indication on the aircraft's ammeter. Although the crew was unable to restore a positive charge indication, they decided to continue the flight to the destination airport.
As the aircraft approached the airport, it suffered a total loss of electrical power. Upon landing, the landing gear collapsed. While the crew reported seeing a gear-down indication prior to the loss of electrical power, an eyewitness positioned near the approach end of the runway observed that the landing gear was not fully extended during the final approach.
The investigation
Post-accident examination of the aircraft's electrical system revealed that the alternator was functioning normally. However, investigators found an aircraft bus voltage of 11.35 volts when energized by the battery (against a nominal 12 volts) and identified a loose alternator drive belt.