The aircraft was engaged on a circuit training detail at EIWF. After the second landing, the aircraft developed a swing to the right during the ground roll along the runway. The Commander called that he had control; however the handling Pilot did not release the flight controls. The aircraft continued its swing and departed from the runway surface, coming to rest in the grass approximately 17 metres (m) from the runway edge. The right hand undercarriage leg collapsed. There were no injuries.