What was found
(CAN) WHEN LANDING AT THE AIRPORT ON A TRAINING FLIGHT THE NLG PARTIALLY RETRACTED TOWARDS THE REAR OF THE ACFT. THE ACFT PITCHED RT AND FULL LT BRAKE WAS USED TO KEEP THE ACFT ON THE RUNWAY. THE ACFT MOMENTARILY LT THE RT SIDE OF THE RUNWAY AND STRUCK A RUNWAY LIGHT WITH THE RT PROPELLER. THE AFT THEN CAME TO A COMPLETE STOP ON THE RUNWAY. UPON INSP OF THE ACFT IT WAS FOUND THAT THE NLG STRUT HSG WAS BROKEN AT THE RT TRUNNION LINK. THIS ALLOWED THE GEAR LEG TO TURN AND MOVE REARWARD UNDER THE ACFT.