As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER NORMAL TAKEOFF, GEAR IN OFF POSITION, LIGHTS OUT, AT 29,000 FT. SPEED AT 290-300 LANDING GEAR CAME DOWN WITH THREE GREEN LIGHTS, AIR DID AN AIR TURN BACK TO REGINA. FOUND TO BE THE SELECTOR VALVE AT FAULT. LANDING GEAR SELECTOR VALVE REPLACED.