What was found
DURING AN ANNUAL INSPECTION, THE LEFT ENGINE, ENGINE MOUNT BEAM ASSEMBLY WAS FOUND CRACKED. THE CRACK WAS MIDWAY IN THE BEAM AND WAS 60-70 PERCENT OF THE WAY THROUGH THE BEAM. THERE WAS A CLAMP ON THE ENGINE DIRECTLY BEHIND THE CRACK, AND THE BEAM MAY HAVE BEEN SCRATCHED BY A TOOL OR BY THE CLAMP UPON INSTALLATION. (THIS WAS INDICATED ON THE RIGHT ENGINE, WHICH HAD THE CLAMP IN THE SAME PLACE, AND HAD A DEEP SCRATCH IN IT). ANOTHER FACTOR THAT CONTRIBUTED TO THE CRACK WAS THAT ALL THE RUBBER SHOCK MOUNTS ON THE ENGINE HAD SAGGED TO A POINT WHERE THE ENGINE WAS RESTING DIRECTLY ON THE BEAM, SO THERE WAS NO ISOLATION FROM ENGINE VIBRATION.