What was found
(CAN) AFTER T/O DEPARTING, THE LANDING GEAR COULD NOT BE SELECTED UP. CREW PERFORMED THE CHECKLIST AND RETURNED. MOC WAS CONTACTED AND A SPECIAL FERRY PERMIT WAS APPLIED FOR AND GRANTED FOR A GEAR DOWN, NON-STOP FERRY FLIGHT. MAINTENANCE FOUND A DEFECTIVE NLG WEIGHT OFF WHEELS SENSOR. PARTS WERE REPLACED AND AN EXTENSION/RETRACTION TEST CARRIED OUT IAW AMM 32-33-00. OPS CHECKED SERVICEABLE. NO FURTHER OCCURENCE.