Accident Overview
On June 14, 2015, about 1000 eastern daylight time, a Weatherly 201B, registration N1272W, was substantially damaged in an accident at St. Clair County Airport (PLR), Pell City, Alabama. The pilot was not injured. The airplane was operating under Title 14 Code of Federal Regulations Part 137 as an aerial application flight.
Pilot Account
The pilot reported landing on runway 21 under clear weather conditions with a slight wind favoring that runway. During a wheel landing in the tailwheel-equipped airplane, the touchdown appeared normal. However, as the airplane rolled out and the pilot lowered the tail, he felt and heard "a jolt." The right main landing gear collapsed, causing the right wing to strike the runway. The airplane then veered "violently" to the right, exited the right side of the runway, and came to rest in the grass bordering runway 21. After exiting, the pilot observed that the right main landing gear had completely separated and was lying in the center of the runway about 500 ft past the touchdown point.
Wreckage Examination
Examination revealed substantial damage from the right main landing gear collapse. The fractured landing gear tubing impacted the forward-facing side of the wing spar, creating an approximate 4-inch-long jagged tear. The right main landing gear assembly itself was fractured at four attachment locations. At many of these attachment points, peeling paint exposed orange-colored metal consistent with oxidation. Fatigue features were identified at the upper inboard attachment point, with the crack initiating from the forward face of the attachment ear where it intersected the adjacent tube. Fatigue features extended through the thickness of the forward plate. The upper outboard attachment also showed indications of fatigue cracking initiating at a similar intersection. The fracture surfaces were heavily damaged, preventing determination of crack lengths before failure. Sliding contact damage in the forward direction was observed at the upper outboard attachment. The lower attachment points exhibited deformation and fracture features consistent with overstress fracture under bending loads, with the lower side of the tube in compression. Additionally, evidence of preexisting cracks was noted on the lower sides of the lower attachments, though the surfaces were damaged and on the compression side.
Inspection History
According to the pilot, the airplane's last annual inspection occurred about 25 days prior to the accident, on May 25, 2015. Appendix D to 14 CFR Part 43 details that annual and 100-hour inspections include inspecting landing gear units for poor condition and insecurity of attachment, as well as linkages, trusses, and members for undue or excessive wear, fatigue, and distortion.