What happened
The pilot intended to perform touch-and-go landings after replacing the nose landing gear micro switch two days prior. Due to a disabled aircraft on runway 23, runway 14 was in use. Following takeoff, the flight remained in the traffic pattern with winds from 230 degrees at 7 knots. The landing gear was extended during the downwind leg, and all gear positions were confirmed via indicator lights.
Upon turning from base to final approach, the aircraft landed with full flaps, making initial contact with the right main landing gear, followed by the left main, and then the nose landing gear. During the landing roll, while using full right aileron and slight left rudder, the right wing raised and the aircraft began to veer to the left. The pilot attempted to correct the deviation by adding power and right rudder, but the aircraft continued to slew harder to the left. Despite applying brakes and flight controls, the aircraft departed the left side of the runway.
The aircraft impacted the upslope of a drainage ditch and came to rest past the ditch. The impact resulted in a sheared nose landing gear and a collapsed left main landing gear, while the right main landing gear remained extended. There were no injuries reported. Marks in the grass were consistent with the movement of the main and nose landing gears, and propeller contact was noted only in the soft ground of the ravine area.
The investigation
An FAA airworthiness inspector examined the left and right main landing gears and found no evidence of failure or malfunction. The downlock rigging was correct, both downlocks functioned as required, and the squat switches were correctly rigged and functional. Additionally, the landing gear warning system and emergency extension system were found to be performing properly. An engineering firm also tested a landing gear relay, which showed no evidence of malfunction.