Accident Summary
On October 27, 2018, at approximately 0750 Pacific daylight time, a Cessna 182G airplane, registration N3267S, was substantially damaged during a landing accident near Burns, Oregon. The private pilot and two passengers were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Sequence of Events
The pilot reported that while approaching the intended landing area in the Alvord Desert, he performed a high reconnaissance to assess wind conditions. After observing two other airplanes land successfully, he configured the aircraft with wing flaps fully down. During the landing roll, the left wing dipped downward. The pilot applied left rudder and right aileron to correct, but the left wing contacted the ground, causing the left main landing gear to shear off and the nose gear to collapse.
Witness Account
A witness observed the landing and photographed part of the accident sequence. She stated that the airplane touched down, then suddenly pitched up before the nose was pushed into the desert terrain.
Landing Gear Examination
The National Transportation Safety Board's Materials Laboratory examined the left main landing gear components. The inboard support showed two rounded rectangular cavities that had contained an attachment bolt. The lower portion of the bolt and nut remained, but the bolt head was missing, with a 45° slanted fracture surface. A V-shaped impact mark indicated a component colliding with the support. Fatigue cracks were found in the threads of both bolts, with corrosion pitting present despite cadmium plating. The right bolt exhibited smaller cracks (less than 100 µm deep). The bolts' hardness corresponded to a tensile strength of 141,000 psi; with a crack depth of 0.13 inch (32% of the cross section), fracture toughness was reduced by at least 45%.
The Textron Aviation Maintenance Manual specified that the bolts securing the outboard channel must be torqued between 660 and 750 inch-pounds with at least 80% contact between the channel and strut.