Amateur-built RV9-A N951DM accident near Twin Falls, Idaho

Probable cause

The pilot's loss of directional control during landing roll for an undetermined reason.

NTSB analysis

In near calm wind conditions, the pilot reported that after he made a normal traffic pattern approach and touchdown his airplane veered "sharply left," and he was unable to redirect the airplane's course back toward the runway using right rudder and right brake. The airplane departed the left side of the runway while rolling between 25 and 30 miles per hour. Thereafter, it rolled onto an open soft dirt field adjacent to the runway's edge, the nose gear dug into the dirt, and the airplane came to rest upside down. The pilot had recent flying experience in the airplane and was current. A Federal Aviation Administration inspector examined the accident site and airplane. He reported observing evidence on the runway of nose gear shimmy. Also, he reported observing evidence that the nose gear created a furrow in the soft dirt consistent with the nose gear wheel being canted sideways before breaking in an aft direction. No mechanical malfunction or anomalies were found with the airplane's flight controls, landing gear system, or brakes. Physical evidence related to the pilot’s loss of directional/steering control was not found. The pilot indicated that he does not know why the airplane's nose gear canted/twisted sideways and precluded him from maintaining directional control during rollout.

Text from the NTSB. Open the NTSB docket for WPR10LA160 for the full record.