Accident Overview
On February 2, 2024, about 1042 central standard time, a Piper PA-24-260 airplane, registration N4284, was substantially damaged during an accident near Cherokee, Oklahoma. The pilot was not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot Actions and Diversion
The pilot reported that the engine began running very rough while in cruise flight at about 2,500 feet mean sea level (msl). He advanced the mixture, propeller, and throttle controls fully forward in an attempt to restore power. Additionally, he selected the left and right magnetos individually to isolate an ignition problem, but the roughness persisted during both magneto checks. Fuel quantity and fuel selector position were confirmed. Unable to determine the cause of the partial power loss, the pilot diverted to the nearest airport, Cherokee Municipal Airport (4O5). However, the airport was covered in ground fog, which hindered the approach. The pilot inadvertently landed long and attempted a go-around, but the airplane lacked sufficient power to climb. It departed the end of the runway, struck the airport perimeter fence, crossed a road, and impacted a second fence before coming to rest. The airframe sustained damage to both wings, the fuselage, and the empennage.
Flight Data Analysis
Ground-based video showed the airplane flying over as it neared the airport, with audio confirming a rough running engine. ADS-B data indicated the airplane was on a southerly course at about 2,254 ft msl, approximately 3.5 miles southeast of the airport. At about 1138:20, the pilot turned right onto a direct course for 4O5 and subsequently entered a modified left downwind before turning final for runway 17. The final ADS-B data point, recorded at 1142:17, placed the airplane over runway 17, about 1,014 ft from the departure end of the runway pavement, at an altitude of about 1,180 ft msl. Runway 17's arrival threshold elevation was 1,178 ft msl, and runway 35's threshold was 1,179 ft msl.
Engine Monitor and Post-Accident Examination
Data from an onboard engine monitor appeared stable until about 1038, when exhaust gas temperature (EGT) for cylinders 4, 5, and 6 decreased abruptly. EGT for cylinders 1 and 3 decreased to a lesser extent, while cylinder 2 remained stable. Fuel flow and fuel pressure parameters remained stable until 1042.
A post-recovery engine examination was unable to identify the cause of the partial loss of engine power. Internal engine and valvetrain continuity were confirmed. Spark plugs displayed normal combustion signatures. The magnetos were secure, and timing was approximately 25° before top dead center, within the specified range. A spark was observed across each ignition lead when the engine crankshaft was rotated. Fuel system continuity was confirmed, and the engine-driven fuel pump was operational. Engine control continuity was also confirmed.