Accident Overview
A pilot reported that after flying around an airstrip for approximately 45 minutes and making several passes, an electronic control unit (ECU) failure indication light illuminated. The engine subsequently lost power, prompting the pilot to enter an autorotation. During the touchdown phase of the autorotation, the helicopter rolled over onto its left side.
Examination and Testing
Examination of the helicopter revealed no fuel in the fuel tanks or at the accident site. The ECUs were removed and subjected to bench testing. The test data indicated that during the last 30 seconds of the flight, throttle position increased while engine RPM decreased. During the final 12 seconds prior to complete engine shutdown, rapid cycling of throttle and RPM was observed.
Flight History
Data retrieved from the ECUs showed that the flight prior to the accident lasted 10 minutes with a three-minute ground run. The accident flight itself lasted approximately 57 minutes. The pilot stated that the helicopter's fuel tank capacity is 14 gallons, and with full fuel the helicopter can fly for 2 hours or 180 miles. According to the pilot, the helicopter departed with 14 gallons of automotive fuel.