What was found
(CAN) AFTER TAKEOFF, THE LANDING GEAR FAILED TO RETRACT, THE AIRCRAFT RETURNED AND LANDED WITHOUT INCIDENT. A SUBSEQUENT INSPECTION REVEALED THAT THE LANDING GEAR SAFETY SWITCH HAD SLIPPED THUS NOT ACTUATING THE SWITCH WHEN THE GEAR WAS FULLY EXTENDED. THE SAFETY SWITCH WAS SECURED, ADJUSTED, AND THE AIRCRAFT WAS RETURNED TO SERVICE.