What was found
DURING ROUTINE VISUAL INSPECTION WHILE REFUELING, CRACK IN TAILBOOM SPAR CAP WAS DETECTED. MECHANIC STATED NO CRACK WAS NOTED DURING PRE-FLIGHT INDICATING IT FORMED WITHIN AN HOUR OF OPERATION. NO FRETTING NOTED TO SUPPORT THIS. GARLICK HELICOPTERS ALERT SB NR UH1-96-04 WAS C/W BY REMOVAL OF RIVET AT FIN STA 70.3. THIS TAILBOOM HAD ACCUMULATED APPROXIMATELY 2,500 HRS OF CIVILIAN SERVICE PERFORMING LOGGING OPERATIONS UNDER PART 133.