NTSB Probable Cause

INADEQUATE MAINTENANCE AND INSPECTION OF THE FUEL INJECTOR SYSTEM RESULTING IN A LOSS OF POWER OF THE LEFT ENGINE, AND THE FAILURE OF THE PILOT TO MAINTAIN MINIMUM CONTROL SPEED WHICH RESULTED IN A FLAT SPIN. A FACTOR WHICH CONTRIBUTED TO THE ACCIDENT WAS THE PILOT LOADING THE AIRPLANE OVER THE MAXIMUM GROSS WEIGHT AND BEYOND THE AFT CENTER OF GRAVITY LIMIT, THUS RAISING THE MINIMUM CONTROL SPEED.