Cessna U206F N592KB accident near Kodiak, Alaska

Probable cause

The failure of the right main landing gear leg due to fatigue cracks that initiated from corrosion pitting.

NTSB analysis

The airplane was the fourth air tour company airplane to land at a remote beach site as part of a bear viewing flight. The pilot set up for a landing on the same tracks as the three previous company airplanes. During the landing, the left main landing gear wheel touched down first, followed by the right main landing gear wheel. When the right wheel touched down, the pilot heard a “pop” sound and the airplane veered to the right. The airplane slowly came to rest upright and sustained substantial damage to the left wing and right horizontal stabilizer. Postaccident examination revealed that the right main landing gear leg was fractured near the wheel attachment fitting.

Materials laboratory examination of the right main landing gear leg revealed that the gear leg fractured during landing due to fatigue cracks that initiated from localized corrosion pitting. The area of the fatigue cracks which was absent paint and primer, contained many elements typical of salt corrosion in a marine environment. Repeated abrasive wear from landings on rough terrain or runway asphalt had likely removed the protective coatings in the area of the fatigue cracks.

Text from the NTSB. Open the NTSB docket for ANC22LA040 for the full record.