What was found
ON TWO DIFFERENT SCHWEIZER HELICOPTERS EQUIPPED WITH HIO360D1A ENGINES, NR 2 CYLINDER BROKE 6 BASE STUDS. THE TWO THROUGH-STUDS REMAINED INTACT IN BOTH CASES. ONE ENGINE HAD 932 HOURS AND THE OTHER 1,424 HOURS SINCE MAJOR OVERHAUL. BREAKS ARE CLEAN WITH NO SIGNS OF WORKING OR LOOSENESS AND OCCURS JUST BELOW NUT.