A B727-200 WAS DISPATCHED IN NON COMPLIANCE WITH THE R MAIN GEAR FLYING DOOR INSTALLED INCORRECTLY. DOOR DEPARTED ACFT AFTER TKOF.

Narrative

I RECEIVED TURNOVER FROM PREVIOUS SHIFT. THE FLAP TRACK INSPECTION WAS COMPLETE AND WE NEEDED TO REINSTALL THE FLYING DOOR AND FINISH INSTALLING THE FLAP TRACK FAIRING. WHILE INSTALLING THE FLYING DOOR WE HAD DIFFICULTY POSITIONING THE LINKAGE ON THE DOOR ATTACH POINT WITH LINKAGE OVER THE DRAG BRACE. SEVERAL TIMES WE HAD REPOSITIONED THE DOOR FOR BETTER ACCESS TO INSTALL FAIRING HARDWARE. WE HAD FINISHED THE TASK AND RETURNED THE ACFT TO SVC. I WAS TOLD THAT SOMETIME AFTER TKOF THE FLYING DOOR DEPARTED THE ACFT; UNKNOWN TO THE CREW; AND THEY CONTINUED TO THEIR DEST. UPON ARR IT WAS DISCOVERED MISSING. AFTER REVIEWING THE JOB WE FIRST QUESTIONED THE FORWARD ATTACH FITTING AS BEING AT FAULT. WE ALSO FEEL THERE IS A SLIGHT POSSIBILITY; DURING THE REPOSITIONING OF THE ATTACH LINKAGE IT COULD HAVE BEEN INSTALLED BELOW THE DRAG BRACE. PREVENTION: CONTINUED INSPECTIONS OF FORWARD ATTACH FITTINGS. I BELIEVE WE CAN HAVE BETTER ACCOUNTABILITY FOR THE FLYING DOOR IF THERE WAS A SEPARATE SIGN OFF DETAILING IT. NOTE: THERE IS NO DOOR INDICATION SWITCH FOR THE FLYING DOOR.