AN A320 HAD AN AFT CARGO DOOR WARNING SENSOR ADJUSTED TO CORRECT A CHRONIC TIME DEFERRAL. ACCESS PANEL REMOVED FOR SENSOR ADJUSTMENT NOT SECURED AND DEPARTED THE ACFT.

Narrative

HAD A DEFERRED ITEM INBOUND AFT CARGO DOOR INDICATION INTERMITTENT WITH HISTORY. OPERATED DOOR AND SYS WORKED OK WITH NO FAULTS. FOREMAN INSTRUCTED ME TO CONTACT ONE OF OUR MAINT CTLRS FOR ADDITIONAL TROUBLESHOOTING PROCS. HE TOLD ME (MY FOREMAN) TO GET THE METER THE CTLR CALLED OUT FOR AND TAKE THE READINGS HE WANTED. I DID AND FOUND BOTH SENSORS TO BE OK AND THE ONE TO BE ON THE LOW SIDE OF ADJUSTMENT. MY FOREMAN INSTRUCTED ME TO ADJUST THE STRIKER MECHANISM TO GET THIS SENSOR IN THE MIDDLE OF THE READINGS THE CTLR CALLED OUT. TO DO THIS I HAD TO REMOVE A PANEL ON THE OUTSIDE OF THE CARGO DOOR. I REMOVED PANEL AND MADE ADJUSTMENTS TO GET THE READINGS THE CTLR AND FOREMAN WANTED. I TOLD THE FOREMAN I WAS GOING TO CALL CTLR AND TELL HIM MY ACTIONS. AT THIS TIME; I ASKED ANOTHER MECH TO REPLACE THE PANEL I REMOVED. THE FOREMAN AND HIM (MECH) REINSTALLED PANEL. I DISCUSSED MY ACTIONS WITH CTLR AND HE SAID TO USE HIS NAME IN SIGNOFF; SINCE IT WAS THE LAST DAY ON DEFERRAL. (THE ADJUSTMENTS WERE MADE USING THE CTLR'S INFO.) WE OPERATED DOOR HANDLE NUMEROUS TIMES AND INDICATION WAS GOOD. I SIGNED THE ITEM OFF. THE OTHER MECH WAS NOT AROUND SO I DID NOT PUT HIS NUMBER OR MAKE A SEPARATE ITEM FOR PANEL. THE LIGHT CAME ON AGAIN INFLT AND WHEN FLT CREW DID THEIR WALKAROUND; THEY FOUND PANEL MISSING FROM ACFT AT NEXT STATION.