NTSB Probable Cause

INADEQUATE MAINTENANCE, AND OPERATION BY THE PILOT WITH KNOWN DEFICIENCIES IN THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT WERE: EXCESSIVE WEAR IN BOTH ENGINES, IMPROPER USE OF POWERPLANT CONTROLS BY THE PILOT, SUBSEQUENT OVERTEMPERATURE/DETONATION IN BOTH ENGINES, IMPROPER EMERGENCY PROCEDURES BY THE PILOT (INCLUDING PREMATURE GEAR EXTENSION AND/OR FAILURE TO PROPERLY REDUCE DRAG ON THE AIRCRAFT AFTER LOSS OF ENGINE POWER), AND THE PILOT'S LACK OF EXPERIENCE IN MULTI-ENGINE AND THIS MAKE AND MODEL OF AIRCRAFT.