What was found
ACFT IN CRUISE AT 4,000 FEET ON IFR FLIGHT PLAN WHEN ENGINE SUDDENLY LOST POWER. ALL ATTEMPTS MADE BY PILOT TO RESTART THE ENGINE UNSUCCESSFUL. PILOT WAS ABLE TO MAKE A FORCED LANDING IN A COW POSTURE. INVESTIGATION AND ENG TEAR DOWN REVEALED LT MAG HAD SEIZED. MORE SPECIFICALLY, THE RIVETS WHICH RETAIN PAWLS INSIDE IMPULSE COUPLING ASSY, PN M3635, HAD FAILED CAUSING PAWLS TO JAM BETWEEN MAG HOUSING AND THE IMPULSE COUPLING ASSY. THIS PREVENTED MAG FROM TURNING WHICH DAMAGED BOTH THE CRANKSHAFT AND IDLER GEARS IN ENG ACCY HOUSING. INSP OF THE IMPULSE COUPLING ASSY AND RETAINING RIVETS ARE DETAILED IN SLICK L-1363 MAIN AND O/H MANUAL, WHICH, ACCORDING TO SLICK, IS REFERENCED IN THEIR 500 HOUR INSP.