Incident Description
After takeoff, while the flight crew retracted the landing gear, the warning light for the right main landing gear (MLG) door remained illuminated. The crew cycled the landing gear in an attempt to correct the condition, but the light did not extinguish. Subsequent attempts to extend the right MLG were unsuccessful, and the gear remained partially extended. The aircraft landed with the left main landing gear and nose gear extended, while the right MLG remained partially extended.
Examination Findings
Following the landing, the aircraft was lifted from the runway. The right main landing gear then fell freely. The uplock hook was found in the up position. Inspection revealed that the door actuator bolts were loose and that the serrated plate had been displaced. The bolts, which are required to be torqued to between 25 and 42 foot-pounds, were found significantly under-torqued: the inboard bolt was torqued to 10 foot-pounds, while two other bolts were only finger-tight. The actuator fitting was displaced fully outboard.
Applicable Service Information
Boeing Service Letter 727-SL-32-47 applies to this condition.