Stinson 108 N955C accident near Red Lodge, Montana

Probable cause

A deer running across the runway and impacting the left side of the airplane, resulting in a loss of directional control, a runway excursion, and a ground loop.

NTSB analysis

The pilot of the tailwheel equipped airplane reported that during takeoff he noticed movement from the left as a deer ran onto the runway. He further reported that he applied right rudder to avoid hitting the deer, but the deer impacted the airplane between the left pilot's door and the horizontal stabilizer causing the airplane to veer to the left. The pilot stated that he attempted to recover by applying maximum right brake and right rudder, however it was ineffective and the airplane exited the runway to the left, ground looped, and nosed over. The airplane sustained substantial damage to both wings, empennage and fuselage.

The pilot reported that there were no pre impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for GAA16CA369 for the full record.