What happened
During the landing roll, the pilot of the aircraft felt a vibration simulating a wheel shimmy condition. As the aircraft crossed the intersection of runway 14 and runway 23, the pilot reported that the airplane became "light." While attempting to maintain control, the right wing collided with the runway. The aircraft then slid to the right and came to a stop in the grass on the south side of the intersection of runway 14 and taxiway A, approximately 2,650 feet from the approach end of runway 14. The pilot was not injured.
The investigation
An examination of the aircraft revealed damage to the propeller, a broken drag brace, an upwardly bent left flap, damage to the underbelly of the fuselage, a collapsed right main gear, and a scraped right elevator tip. Further inspection showed that the inboard section of the right wing was bent, and there was damage to the right aileron, the right flap, and the right wing rear spar.
An examination of the right landing gear assembly revealed that the down lock adjustment stud was broken. A mechanic's visual examination of the fracture face on the stud showed that approximately 3/4 of the surface appeared to be an old fracture, while 1/4 appeared to be a fresh fracture. The maintenance history regarding the down lock adjustment stud could not be determined, and efforts to secure the fractured stud for further study were unsuccessful.