Narrative:

Upon landing gear retraction the right main landing gear indicator light remained red/unsafe. I requested the gear be lowered with all 3 subsequently indicating green/safe and then again retracted with the right main gear once again showing red/unsafe. Again I asked the gear be lowered and again received a green/safe indication at which time the gear was left in the down and locked position. I mentally concluded since there was no adverse yaw or heavy buffeting that the problem was either a) a landing gear door not connected or B) a misaligned/misadjusted sensor microswitch. However, not being able to determine which condition actually existed, a return to sjc was initiated. Departure control was immediately informed of our difficulty and assisted with vectors for the ILS to runway 30L and alerting the emergency equipment I requested to be standing by. F/a's were notified along with the passenger that a return to sjc was necessary due to 'a minor' cockpit warning light illumination, however F/a 'a' was instructed specifically not to prepare the cabin for an emergency landing, but to follow normal landing preparation procedures. The landing was textbook and upon arriving at gate the maintenance lead came to the flight station and stated that the right main landing gear door had not been properly reconnected last night upon completion of changing the right main outboard tire. He further stated that the mechanic responsible for the work had omitted this on previous occasions and that he would get the maintenance supervisor. The maintenance supervisor informed me that this mechanic had been advised/counseled re: his work, that this was the last error they could afford to allow him to make and that he would take steps to insure the proper disciplinary action was taken. I questioned my first officer re: his exterior walk around procedures and he assured me that the landing gear door appeared normal, although he did not specifically attempt to lift or move the door. The door was reconnected within 2 mins and upon receiving a new/amended dispatch release we again departed for san diego--this time uneventfully.

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Original NASA ASRS Text

Title: ACR MLG UNABLE OBTAIN SAFE GEAR UP INDICATION AFTER TKOF, RETURN AND LAND.

Narrative: UPON LNDG GEAR RETRACTION THE RIGHT MAIN LNDG GEAR INDICATOR LIGHT REMAINED RED/UNSAFE. I REQUESTED THE GEAR BE LOWERED WITH ALL 3 SUBSEQUENTLY INDICATING GREEN/SAFE AND THEN AGAIN RETRACTED WITH THE RIGHT MAIN GEAR ONCE AGAIN SHOWING RED/UNSAFE. AGAIN I ASKED THE GEAR BE LOWERED AND AGAIN RECEIVED A GREEN/SAFE INDICATION AT WHICH TIME THE GEAR WAS LEFT IN THE DOWN AND LOCKED POS. I MENTALLY CONCLUDED SINCE THERE WAS NO ADVERSE YAW OR HVY BUFFETING THAT THE PROB WAS EITHER A) A LNDG GEAR DOOR NOT CONNECTED OR B) A MISALIGNED/MISADJUSTED SENSOR MICROSWITCH. HOWEVER, NOT BEING ABLE TO DETERMINE WHICH CONDITION ACTUALLY EXISTED, A RETURN TO SJC WAS INITIATED. DEP CTL WAS IMMEDIATELY INFORMED OF OUR DIFFICULTY AND ASSISTED WITH VECTORS FOR THE ILS TO RWY 30L AND ALERTING THE EMER EQUIPMENT I REQUESTED TO BE STANDING BY. F/A'S WERE NOTIFIED ALONG WITH THE PAX THAT A RETURN TO SJC WAS NECESSARY DUE TO 'A MINOR' COCKPIT WARNING LIGHT ILLUMINATION, HOWEVER F/A 'A' WAS INSTRUCTED SPECIFICALLY NOT TO PREPARE THE CABIN FOR AN EMER LNDG, BUT TO FOLLOW NORMAL LNDG PREPARATION PROCS. THE LNDG WAS TEXTBOOK AND UPON ARRIVING AT GATE THE MAINT LEAD CAME TO THE FLT STATION AND STATED THAT THE RIGHT MAIN LNDG GEAR DOOR HAD NOT BEEN PROPERLY RECONNECTED LAST NIGHT UPON COMPLETION OF CHANGING THE RIGHT MAIN OUTBOARD TIRE. HE FURTHER STATED THAT THE MECH RESPONSIBLE FOR THE WORK HAD OMITTED THIS ON PREVIOUS OCCASIONS AND THAT HE WOULD GET THE MAINT SUPVR. THE MAINT SUPVR INFORMED ME THAT THIS MECH HAD BEEN ADVISED/COUNSELED RE: HIS WORK, THAT THIS WAS THE LAST ERROR THEY COULD AFFORD TO ALLOW HIM TO MAKE AND THAT HE WOULD TAKE STEPS TO INSURE THE PROPER DISCIPLINARY ACTION WAS TAKEN. I QUESTIONED MY F/O RE: HIS EXTERIOR WALK AROUND PROCS AND HE ASSURED ME THAT THE LNDG GEAR DOOR APPEARED NORMAL, ALTHOUGH HE DID NOT SPECIFICALLY ATTEMPT TO LIFT OR MOVE THE DOOR. THE DOOR WAS RECONNECTED WITHIN 2 MINS AND UPON RECEIVING A NEW/AMENDED DISPATCH RELEASE WE AGAIN DEPARTED FOR SAN DIEGO--THIS TIME UNEVENTFULLY.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.