Accident Overview
On April 16, 2020, at approximately 1145 Eastern standard time, a Beech A36, registration N66FN, sustained substantial damage during an accident near Cincinnati, Ohio. The pilot, the sole occupant, was not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Events Leading to Engine Failure
The pilot reported that the flight originated from Indianapolis, Indiana (UMP), with a destination of Cincinnati, Ohio (LUK), for planned maintenance. En route, the pilot was performing an altitude leaning schedule to diagnose high exhaust gas temperature (EGT) readings. During the flight, he performed step-up climbs to 14,000 ft to record power settings. After completing the test schedule, while descending to about 2,500 ft, the pilot noticed an "unusual" vibration not previously experienced. He checked the engine analyzer and observed that one cylinder was not producing an EGT reading. Shortly thereafter, a second cylinder EGT dropped offline, followed by a third. Cylinder EGTs continued to drop offline, and subsequently the engine quit.
Emergency Landing
The pilot was unable to restart the engine and declared an emergency. The airplane was over a heavily populated area north of downtown Cincinnati, so the pilot maneuvered for an emergency landing on a roadway. During the landing, the left wing struck a wooden post along the edge of the road. The nose pitched left, and the airplane landed hard on the right main landing gear and nose gear, causing the landing gear to collapse. The airplane then pitched right and struck another wooden post on the opposite side of the roadway with the right wing. The nose contacted a concrete bridge abutment, and the airplane slid under an overpass. The pilot secured the fuel and master switch before exiting.
Postaccident Examination
A postaccident examination of the airplane and engine was conducted. The top spark plugs were removed, and compression was verified to the cylinders. Air intake hoses and clamps were secure and tight with no obstructions. Magnetos sparked at all terminals. Engine controls were free and had full travel. The mixture control screen was removed and found free of debris. Fittings and hoses on the mixture control, fuel manifold valve, and fuel pump were checked for security. Both the fuel inlet and fuel return line fittings on the fuel pump were found loose and could be turned by hand. No adjacent impact damage was noted around the loose fittings. According to maintenance records, the fuel pump had been removed and replaced on April 14, 2020, two days prior to the accident. According to the engine manufacturer, a loose inlet fitting could result in a loss of engine power.