A B727-200 WAS DISPATCHED IN NON COMPLIANCE WITH A KNOWN NOSE GEAR DOOR LOCKING MECHANISM DAMAGED AND NOT CORRECTED.

Narrative

PRIOR TO LUBING THE NOSE LNDG GEAR DRAG BRACE MECHANISM; I OPENED THE NOSE LNDG GEAR DOORS FOR EASE AND BETTER LIGHT. AFTER LUBING THE NOSE LNDG GEAR DRAG BRACE; I CLOSED AND LOCKED BOTH NOSE LNDG GEAR DOORS -- 100% POSITIVE OF PROPER DOOR CLOSURE AND SECURITY. DAY SHIFT CREW TOOK THE ACFT OVER AT SHIFT CHANGE. ACFT THEN WENT TO RUN-UP HOLE FOR ENG RUN; THEN TOWED BACK TO THE HANGAR PAD. GEAR DOORS WERE STILL UP AND LOCKED AT THIS TIME. SUPER TUG THEN TOOK THE ACFT TO THE GATE WHERE THEY SAY THEY SAW THE NOSE LNDG GEAR DOOR FALL. THEY TRIED TO PUSH DOOR UP; BUT DECIDED TO GET THE ACFT TO THE GATE AND DO IT THERE. THEY THEN TRIED TO PUSH TO NOSE LNDG GEAR DOOR UP AT THE GATE. THEY TOLD NOBODY OF THE PROB AND LEFT THE ACFT. THE ACFT DEPARTED ZZZ AND ON TKOF; THE NOSE LNDG GEAR DOOR DEPARTED THE ACFT CAUSING AN AIR TURN BACK. I WAS NOTIFIED OF THE INCIDENT THAT NIGHT WHEN I CAME IN TO WORK. I AM VERY COMPETENT IN MY WORK AND HAVE NO REASON TO QUESTION MY ABILITY TO DO AND COMPLETE A JOB LIKE CLOSING AND SECURING THE B727 NOSE LNDG GEAR DOORS PROPERLY. I AM CONFIDENT THAT THE NOSE LNDG GEAR DOORS WERE CLOSED; LOCKED AND SECURED PROPERLY.