Accident Overview
On July 20, 2022, at about 0815 mountain daylight time, a Maule M-5-235C, registration N6224M, sustained substantial damage during a forced landing in Three Forks, Montana. The commercial pilot, who also held a mechanic certificate with airframe and powerplant ratings and inspection authorization, was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot's Account
According to the pilot, this was the first flight following an engine and magneto overhaul, as well as the installation of new avionics. He reported completing several engine test runs and multiple full-power, high-speed test runs before departure. Confident of the engine's performance, he departed for a local flight to continue engine break-in procedures. He conducted several flight maneuvers, and the engine operated normally.
While established in the right traffic downwind leg of the airport traffic pattern with the intent to land, the pilot noticed that the engine rpm was winding down slowly. He attempted to troubleshoot the anomaly without success. He pitched for best glide with no flaps and made a right 180° turn for runway 03, but the airplane's sink rate was too high to reach the runway. The airplane touched down about 1,000 feet short of the runway threshold on an unplowed pasture and collided with a barbed wire fence.
Damage Assessment
The airplane sustained substantial damage to its longerons near the wing's attach points, the left-wing spar, and lift struts.
Postaccident Examination
Examination of the engine's single-drive dual magneto revealed that the right magneto capacitor wire was attached using an automotive-style terminal bent 90°, rather than a right-angle flag terminal. The wire had separated within the crimped section of the terminal. Additionally, the left magneto P-lead was deteriorated and had an area of exposed wire that resulted in a ground fault when tested with a multimeter.
Pilot's Reflection
The pilot reported that he could have avoided the accident if he had immediately turned toward the runway when the engine began losing power, rather than continuing the downwind leg while troubleshooting.