Event Description
On June 8, 2012, about 1015 Pacific daylight time, a Cessna 120, registration N1875N, experienced a runway excursion during landing at Farias Wheel Airport (NV33) in Smith Valley, Nevada. Valley View Flyers LLC operated the airplane under 14 CFR Part 91. The private pilot was not injured, but the airplane sustained substantial damage. The cross-country personal flight departed Yerington, Nevada, about 0955, with a planned destination of NV33. Visual meteorological conditions prevailed, and no flight plan had been filed.
Pilot Report
The pilot reported that during landing, the airplane bounced. Upon touchdown, it suddenly veered to the left. He applied power to abort the landing, but the airplane continued left and departed the runway surface into sagebrush. The right main landing gear collapsed, and the right wing and propeller contacted the ground. The pilot turned off the master switch, shut off the fuel, and exited the airplane.
Examination
A Federal Aviation Administration (FAA) inspector examined the wreckage on site. He noted that the fracture surface of the right main landing gear was flat with beach marks. The part was submitted to the National Transportation Safety Board (NTSB) Materials Laboratory for examination.
Metallurgical Analysis
An NTSB metallurgist observed that the main landing gear strut was transversely fractured through the upper attachment hole for the step bracket. The upper fracture face was mechanically damaged, while the lower face was mostly undamaged. Optical examinations revealed chevron markings indicative of fracture initiation on both sides of the hole at the corners formed by the hole’s bore and the upper surface of the strut. Closer magnified examinations uncovered small fatigue cracks at both corners of the hole. The fatigue on the forward side of the hole initiated at three locations in a corrosion pitted area of the bore surface. The aft fatigue region initiated at a single origin at the corner in a corroded area. Corrosion was visible in unpainted areas. Removing the remnant paint from the bore revealed corrosion and corrosion pitting over the entire bore surface.
The airplane was built in 1946 and had a total airframe time of 8,934 hours.