ANC18LA030 · Champion 7GC

The pilot was landing at the airport after a personal flight. After obtaining weather information for the destination airport, the pilot contacted the air traffic control (ATC) tower and requested to land on the runway that corresponded to the current wind condition. The pilot's intent was to land with a direct headwind. The controller responded that the requested runway was not available due to other airplanes landing and directed the pilot to land on another runway that would result in the airplane landing with a crosswind.

The pilot reported that the approach was stable. Upon touchdown, the airplane began to ground loop to the left, so she applied rudder and brake inputs as a corrective action, with no success. Subsequently, the right main landing gear separated, and the right wing impacted the runway; the airplane sustained substantial damage to the right wing and right aileron.

An examination of the main landing gear (right side) strut threaded sleeve and jam nut found that the oleo strut had fractured. Overstress fracture features were consistent with the sleeve fracturing from the end of the oleo strut assembly with the assembly loaded in tension.

No evidence of progressive or long-term cracking was observed on the fracture surface, which indicates that no cracks developed in the braze due to the low-tension loads during flight or due to attachment loads from assembly of the cap onto the strut cylinder assembly. Although the brazed joint between the sleeve and the oleo strut tube did not conform to the engineering drawing and the strength would have been substantially less than a properly brazed joint, there was no evidence to indicate that the joint would have separated if loaded as designed; the joint appeared to be strong enough to perform under normal operation given that there was no evidence of progressive fracture. Therefore, the strut likely fractured due to abnormal side loading of the wheel with little or no loads in the upward direction as the airplane tipped to the right during the landing sequence involving the ground loop to the left.

The pilot reported she should have "held firm" to her request to land with a headwind and not a direct crosswind or quartering tailwind. She further reported that in the "future I will be more firm in my requests as pilot in command for the runway that I feel comfortable with and will wait as necessary for tower permission to use my requested runway." It is likely that if the pilot had contacted the ATC tower again and waited to land to her original runway of choice, the landing would have had a direct headwind instead of a crosswind. The pilot's decision to land on a runway with a crosswind was likely due to self-induced pressure to land.

Verbatim NTSB analysis and probable cause from the NTSB dataset