As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB APPROXIMATELY 1 MINUTE AFTER GEAR HANDLE PLACED IN THE OFF POSITION THE LANDING GEAR EXTENDED. GEAR HANDLE WAS PLACED IN THE UP POSITION, FOR GEAR RETRACTION, AND WAS LEFT THERE WHILE THE FLIGHT PROCEEDED AT REDUCED AIR SPEED. RIGGED LGVB AND LGVA CABLES PER MM 32-31-0 DUE TO LOW TENSION AND MISALIGNMENT OF THE SHAFT DRUM ASSEMBLY. CHECK-C 9-7-99 MCI.