What happened
A pilot and mechanic was conducting a test flight to verify the rigging of the flight controls. During the approach for landing, the engine lost power. The pilot was utilizing a steep, nose-low attitude during this phase of flight when the loss of power occurred. The aircraft landed short of the runway threshold and encountered a puddle of water approximately one foot deep, which caused the airplane to nose over.
The pilot reported that the aircraft was low on fuel and was operating in turbulent air at the time of the incident. Following the nose-over, the aircraft was destroyed by an explosion and fire during the recovery process. The pilot was not injured.