A B737-400 WAS DISPATCHED AFTER MAINT WITH THE POSSIBILITY OF A TOOL LEFT IN THE #1 ENG COWLING AND SUBSEQUENT INSPECTION FOUND NO TOOL IN COWLING.

Narrative

ON OCT/XX/97; DURING THE INSTALLATION OF THE WIRING OF ENGINEERING ORDER #XYZ (THRUST REVERSE SYNC LOCK MODIFICATION) I WAS INSTALLING SAFETY WIRE ON THE SYNC LOCK CANNON PLUG BACKSHELL ON THE #1 ENG. THIS TOOK PLACE DURING THE LAST PHASE OF THIS ENGINEERING ORDER AND NEAR THE COMPLETION OF THIS ACFT'S VISIT FOR SCHEDULED MAINT (QCHK). THE ACFT WAS RELEASED FOR SVC ON OCT/XA/97. IT SEEMS I MAY HAVE LOST A PAIR OF SAFETY WIRE PLIERS AT THIS TIME. THE NEXT TIME I NEEDED TO USE THE SAFETY WIRE PLIERS WAS ON OCT/XB/97. I LOOKED FOR THE PLIERS AND WAS UNABLE TO FIND THEM AT MY WORK AREA OR IN MY TOOL BOX. ON OCT/XC/97; I REMEMBERED THE LAST PLACE I USED THE PLIERS WHICH WAS ON THE #1 ENG ON THE OUTBOARD SIDE. THE PLIERS MAY HAVE FALLEN AND LODGED BEHIND THE MECHANISM DURING THE CLEAN UP AND COMPLETION OF THE SYNC LOCK ENGINEERING ORDER. AT THIS POINT I CONTACTED MAINT CTL THROUGH A SAFETY COORDINATOR TO HAVE THE ENG COWL OPENED FOR INSPECTION AS SOON AS MAINT WAS AVAILABLE AT A STATION WHERE THE ACFT HAD ARRIVED. ACFT #1 ENG COWL OPENED AT XYZ ON OCT/XD/97 XY00 HRS (NOTHING FOUND).