Accident Overview
On January 19, 2019, at approximately 1125 central standard time, a Stinson 108-1, registration N97969, was involved in an accident on the Menominee Indian Reservation near Keshena, Wisconsin. The aircraft was operated as a personal flight under Title 14 Code of Federal Regulations Part 91. The private pilot sustained serious injuries, and the three passengers suffered minor injuries. The airplane was substantially damaged.
Pilot Report
The pilot stated that the purpose of the flight was to travel to Ford Airport (IMT) in Iron Mountain, Michigan. Before departure, the airplane had 26 gallons of fuel onboard. During cruise flight, the engine experienced a sudden and significant drop in rpm, from about 2,300 rpm down to approximately 1,500 rpm. In response, the pilot moved the mixture to full rich, activated carburetor heat, and switched to the right fuel tank. The engine recovered, and the pilot left the carburetor heat engaged for about three minutes before slowly turning it off. Approximately two minutes after deactivating the carburetor heat, the engine ceased producing power entirely. The pilot noted that the propeller did not windmill after the power loss.
Forced Landing and Damage
The pilot attempted to engage the starter, but it did not engage. He spotted an asphalt road bordered by trees on both sides and decided to perform a forced landing. During the landing, the airplane struck trees, bounced on the road, and came to rest inverted on a snow-covered embankment. All occupants were able to exit the aircraft without further incident. The fuselage, both wings, and the empennage sustained substantial damage.
Postaccident Examination
A postaccident examination of the engine by the Federal Aviation Administration (FAA) revealed no preexisting mechanical malfunctions or failures that would have prevented normal operation. The temperature and dewpoint at the accident time were not conducive to carburetor icing formation, according to the carburetor icing probability graph from FAA Special Airworthiness Information Bulletin CE-09-35 Carburetor Icing Prevention. The pilot did not submit the required National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1, despite a request.