A B737-800 ACFT MECHANIC REALIZED AFTER TURNING IN HIS JOB CARD; THAT ANOTHER MECHANIC COULD HAVE LOOSENED THE FWD ATTACH POINTS OF THE R OUTBOARD AFT FLAP; AFT SUPPORT FAIRINGS.

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I WAS ASSIGNED TO WORK ACFT X NON-ROUTINE WORK CARD. I WAS ASSIGNED THE TASK OF ASSISTING 3 OTHER TECHNICIANS TO REMOVE AND REPLACE A LEASED R OUTBOARD AFT FLAP. WHEN I ARRIVED ON THE JOB; 2 OF THE TECHNICIANS WERE ALREADY ON THE JOB AND THE AFT FLAP WAS ALREADY REMOVED. THE 2 TECHNICIANS WITH THE HELP OF A THIRD TECHNICIAN INSTALLED AND ADJUSTED THE REPLACEMENT AFT FLAP. ONE OF THE TECHNICIANS ASSIGNED TO THE TASK ORIGINALLY; SHORT SIGNED FOR THE INSTALLATION OF THE FLAP AND LEFT THE JOB. IN ORDER TO REMOVE AND INSTALL THE AFT FLAP; THE FLAP SUPPORT AFT FAIRINGS MUST BE DISCONNECTED. THIS WAS DONE BEFORE I WAS ON THE JOB. THE 2 REMAINING TECHNICIANS AND MYSELF; CONNECTED THE AFT PORTION OF THE FLAP SUPPORT FAIRINGS. THE FORWARD CONNECTION OF THE AFT SUPPORT FAIRINGS; APPEARED TO BE UNDISTURBED. THE FAIRING WAS SUSPENDED FROM THE FORWARD CONNECTION WITH THE ACCESS COVERS TO THE CONNECTION OPEN. THE FORWARD CONNECTION COVERS WERE CLOSED BY THE 2 OTHER TECHNICIANS. TO COMPLETE THE TASK; THE FLAPS WERE OPERATED WHILE AN INSPECTOR CHKED THE INSTALLATION AND ADJUSTMENT OF THE AFT FLAP. I SIGNED FOR OPS CHK 'OK' AND SIGNED THE CARD AS COMPLETED. THE INSPECTOR SIGNED THE CARD AS COMPLETED ALSO. AFTER TURNING THE WORK CARD IN I REALIZED SOMEONE COULD HAVE LOOSENED THE FORWARD ATTACH POINT OF THE FLAP SUPPORT FAIRINGS AND THE ATTACH POINTS MAY HAVE NEEDED TO BE TORQUE CHKED. AT THE TIME I REALIZED THE POTENTIAL PROB; IT WAS SHIFT CHANGE. I FOUND THE ONCOMING INSPECTOR FOR THE ACFT AND ASKED HIM TO WRITE A NON-ROUTINE WORK CARD TO HAVE THE FORWARD ATTACH POINTS OF THE FLAP SUPPORT FAIRINGS TORQUE CHKED. HE SAID HE WOULD DO SO. I AM FILING THIS RPT BECAUSE THE ATTACH POINTS COULD BE LOOSE AND TO ENSURE THE ATTACHMENTS ARE CHKED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED HE WANTED THE FWD ATTACH POINTS OF THE AFT FAIRING TO BE TORQUE CHECKED BECAUSE HE DID NOT BELIEVE ANY ONE OF THE MECHANICS WORKING EARLIER; OR THE THREE WITH HIM; HAD TORQUED CHECKED THE FWD ATTACH POINTS OF THE AFT FAIRING. REPORTER ALSO STATED THE OUTBOARD AFT FLAP; AFT SUPPORT FAIRINGS ARE EASIER TO INSTALL ON THE -800'S; THAN THE OLDER 737-300'S AND-500'S.