Accident Details
On September 10, 2023, at approximately 1200 eastern daylight time, an experimental Sonex airplane, N569SX, was substantially damaged when it impacted terrain near Dowagiac, Michigan. The pilot was fatally injured. The airplane was operating under Title 14 Code of Federal Regulations Part 91 as a personal flight. The accident time was estimated based on departure time and nominal fuel consumption.
The pilot departed Dowagiac Municipal Airport (C91) around 1100 for a local area flight. An alert notice (ALNOT) was issued at 2021 when the pilot had not returned. The wreckage was located four days later in a heavily wooded area about 4 miles north-northeast of C91. An open agricultural field was approximately 60 yards west of the site. No witnesses were known. The airplane came to rest inverted. Trees in the vicinity were up to about 100 ft tall. Fresh tree breaks and a downed tree were found about 30 ft north and 25 ft northwest of the wreckage, respectively.
Aircraft Information
The aft fuselage was crushed and resting on a fallen tree. Both wings exhibited leading-edge crushing damage consistent with impact to trees and terrain. The empennage was damaged consistent with impact forces. Flight control surfaces remained attached, and control continuity was confirmed to the cockpit controls. The engine appeared intact except for minor impact damage to the air filter/intake assembly. The propeller was secured, but both blades were damaged consistent with impact. The fuel tank was intact with about 10 gallons of fluid exhibiting a blue tint consistent with 100 low lead aviation fuel, clear and free of sediment.
Postcrash Examination
A postrecovery examination of the automobile engine revealed the ignition distributor rotor was fractured and separated from the driveshaft. The distributor cap interior showed rotational scoring with fine powder residue but was otherwise intact. Ignition harness leads were secure and undamaged. After installing a new distributor cap and rotor, the engine started and ran normally at idle power.
No ADS-B data associated with the airplane or flight was available. At the on-scene examination, the transponder was observed in the OFF position. The emergency locator transmitter (ELT) was separated from its mounting cradle, and the antenna cable was separated at the coaxial connector. The remaining cable and airframe-mounted antenna appeared intact. The ELT switch was in the OFF position. During postrecovery, the ELT was activated momentarily and its transmission was heard on an adjacent handheld transceiver tuned to 121.5 MHz.
Additional Findings
The Corvair engine had been installed on the airframe just over three years before the accident. The last condition inspection was completed on August 14, 2022, following a Sonex Condition Inspection checklist. The checklist included checking the distributor cap for condition and continuity but did not specifically list inspecting the distributor rotor. At that inspection, the engine had accrued 47.5 hours of operation since installation.
An autopsy performed by the Western Michigan University Homer Stryker M.D. School of Medicine reported the cause of death as blunt force injuries, with the manner of death accident. Toxicology testing at the FAA Forensic Sciences Laboratory found no drugs of abuse.