What was found
STIFFENER, P/N 0412521-3, WAS FOUND CRACKED IN 4 PLACES, .25 INCH TO .3750 INCH LONG. THIS CONDITION WAS CAUSED BY LOOSE BOLTS IN PLATE, P/N 0412010-1, FITTINGS, P/N 0432005-1, AND P/N 0432005-2. BOLTS AND BOLT HOLES WERE WORN EXCESSVIELY. THIS CONDITION CAN BE CHECKED BY PLACING FINGERS ON FITTINGS AND PLATES WHILE SHAKING HORIZONTAL STABILIZER. SUBMITTER STATED THIS LOOSE CONDITION HAS BEEN FOUND ON 3 AIRCRAFT IN THE LAST MONTH. NOTE: ONLY 1 OF 3 AIRCRAFT HAD STIFFENER CRACKED. ACFT TT: 3,520.0 HOURS.