Originally Posted by AAIB

After the aircraft crashed, a BMA engineerentered the flight deck and switched off the main battery switchand the standby power switch. He later returned to the flightdeck and switched off the engine ignition (engine start switches)and the fuel booster pumps. The engine start levers (fuel valves)were found in the cut-off position. No witness was found whocould testify to having moved them.