As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT ROLL ON TAKE-OFF. DURING CLIMB FLIGHT CREW SELECTED GEAR UP. MAIN LANDING DOOR CYCLES UP AND DOWN, UNTIL THE PILOT RE-SELECTED GEAR IN DOWN POSITION. AIRCRAFT CAME BACK LANDING AT IT'S MAINTENANCE BASE. MAINTENANCE PERSONNEL FOUND THAT THE LT FREE FALL CLEVIS CABLE ON THE UPLOCK ASSY HAD'NT RESET TO IT'S PROPER POSITION. CABLE WAS RESET AND FUNCTION CHECK SERVICEABLE ON GROUND.