Accident Summary
A flight instructor and a commercial pilot were practicing landings on a hard-surfaced runway. During the accident landing roll, the airplane's right main landing gear collapsed, and the airplane veered off the runway. Prior to touchdown, the flight instructor stated that he verified the landing gear were in the down position, with all three gear down indicators illuminated.
Landing Gear Examination
A postaccident inspection of the landing gear mechanism disclosed that the left main landing gear and the nose gear were fully extended; however, the right main landing gear was almost fully retracted.
Actuator Findings
Examination of the right main landing gear actuator revealed that it had bulged and cracked along the axis of the hydraulic cylinder. The fracture surfaces of the crack were indicative of overload fracture, with no evidence of fatigue cracks.