As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON TAKEOFF, LANDING GEARS WOULD NOT RETRACT WITHOUT USING GEAR OVERRIDE. AIRCRAFT RETURNED. LANDING GEAR ACCESSORY MODULE REPLACED AS PER WORK CARD 4281. OFF CANADIAN PART 7-326-9-0010 SERIAL 0054, ON SERIAL #0438. FURTHER TROUBLESHOOTING FOUND AIR SENSOR OUT OF TOLERANCE. SENSOR ADJUSTED AS PER MM 32-09-200, PAGES 501. GEAR SWING ACCOMPLISHED AND CHECKED OK.