What was found
PILOT REPORTED THAT ENGINE BEGAN RUNNING ROUGH. READINGS FORM THE ENGINE MONITOR SHOWED THAT NR 2 CYLINDER FAILED. PILOT ELECTED TO LAND. INVESTIGATION SHOWED THAT BOTH UPPER THROUGH BOLTS AND BOTH UPPER CYLINDER ATTACH STUDS FOR NR 2 CYLINDER HAD FAILED AT THE CYLINDER FLANGE. THE LOWER AT THROUGH BOLT FOR NR 1 CYLINDER WAS ALSO FOUND FAILED AT THE CYLINDER FLANGE. ALL 4 CYLINDERS HAD BEEN REPLACED 205.2. HOURS PREVIOUSLY AT 4177.7 HOURS. FAILURE OF THE STUDS AND BOLTS APPEARS TO BE CONSISTENT WITH EITHER UNDER TORQUE OR OVER-TORQUE OF THE NUTS AT INSTALLATION. (K)