What was found
ENGINE FAILURE OCCURRED UPON REACHING 4,500 FEET. EMERGENCY LANDING AT AIRPORT WAS MADE. INVESTIGATION DETERMINED MAGNETO HAD FALLEN OFF ENGINE. INSPECTION REVEALED MAGNETO HAD BEEN REMOVED 4 MONTHS EARLIER TO C/W AD 78-09-07RE. UPON REINSTALLATION OF MAGNETO, A FLANGED TYPE GASKET P/N 62224 HAD BEEN USED INSTEAD OF PROPER ROUND GASKET, P/N CW12681. THIS ALLOWED GASKET MATERIAL TO BE COMPRESSED BETWEEN MAGNETO HOLD-DOWN CLAMPS AND ACCESSORY HOUSING RESULTING IN IMPROPER TORQUING AND SUBSEQUENT FAILURE.