Accident Overview
On June 1, 2021, at approximately 1720 eastern daylight time, a Beech A23, registration N8780M, was substantially damaged in an accident near Pinnacle, North Carolina. The student pilot was fatally injured, and the flight instructor sustained serious injuries. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
Flight History
The flight instructor reported that after performing a series of maneuvers while transitioning between practice areas, the engine experienced a total loss of power. Multiple attempts to restart the engine were unsuccessful, and she performed a forced landing to a field. Flight track data indicated that the airplane departed runway 22 at Smith Reynolds Airport (INT) in Winston Salem, North Carolina, at about 1641. The airplane then tracked northwest, then east, executing turns, climbs, and descents consistent with maneuvering flight. At approximately 1718, while on an easterly track, the airplane entered a right descending 270-degree turn from about 2,100 feet mean sea level (msl). The last radar target was recorded at 1719 as the airplane descended through 1,075 feet msl at a groundspeed of 64 knots, about 16 miles northwest of INT. The accident site elevation was approximately 1,000 feet.
Wreckage Examination
The airplane impacted a grass field on a residential property. The wreckage debris path was approximately 65 feet long and oriented on a magnetic heading of 162 degrees. No postimpact fire occurred, and all major structural components were within the debris field. Flight control cables were continuous from cockpit controls to control surfaces, and manual manipulation of aileron, stabilator, and rudder cables operated their respective surfaces. The outboard portion of the left wing came to rest inverted next to the inboard portion; the left wing was impact-separated at the wing root, with aileron cables remaining attached. The empennage separated from the fuselage and came to rest behind the cabin; elevator and rudder cables remained attached. The engine was partially separated, with fuel hoses, throttle, and mixture control cables remaining attached. The nose and right main landing gear were separated.
Fuel System and Engine Examination
The engine fuel supply system remained intact. The fuel boost pump switch lever was fracture-separated, but the remaining portion was in the "ON" position. The left fuel tank was breached; the right fuel tank remained intact and contained about 1 pint of aviation fuel, free of water and debris. Grass blighting was evident at the initial left wing impact location and continued along the wreckage path. The fuel flow divider and fuel injector lines contained no fuel; they were disassembled and found free of debris. The fuel line from the engine-driven fuel pump to the fuel metering assembly contained fuel, and the line from the metering assembly to the flow divider contained a small amount of fuel. The fuel selector was in the right tank position, and the valve contained a small amount of fuel. Fuel outlet strainers in each wing and all fuel supply lines and vents were free of obstructions. No fuel supply lines forward of the firewall were breached. The electric fuel boost pump was removed, connected to a power supply, and successfully operated, pumping water.
Both magnetos were removed and manually operated; they produced spark on all leads. The top spark plugs were in new condition compared to a Champion Spark Aviation Check-A-Plug chart AV-27. The engine was manually rotated, continuity was confirmed, and thumb compression was verified on all cylinders. Cylinder valves appeared well lubricated, with associated rockers and springs functioning smoothly. The crankcase contained 6 quarts of oil. The oil filter was cut open, and the pleats were free of ferrous material or debris. The propeller remained attached to the crankshaft flange; Blade A was unremarkable, while Blade B was uniformly bent aft around the engine. Blade B was cut from the hub to facilitate engine rotation. Neither blade exhibited leading edge gouging or polishing.
Additional Information
According to the airplane flight log, the airplane flew 2.8 hours since being fueled to capacity one week before the accident. After 1 flight hour, the left and right fuel tanks were "1/2 and FULL," respectively. After the next flight of just over 1 hour, the tanks were "2/3 and 1/2," the same as preflight fuel levels for the accident flight. The flight instructor noted that they departed with about 30 gallons of fuel. The airplane was equipped with a 59.8-gallon fuel system, of which 58.8 gallons were usable; each wing tank held 29.9 gallons. Average fuel consumption was about 9 gallons per hour (gph), but the flight log indicated consumption of about 14 gph. The pilot operating handbook stated that the fuel return line from the engine-driven fuel pump returns about 3 to 6 gallons per hour to the left tank at 75% power or less. The handbook included emergency procedures for engine failure after liftoff or in flight at sufficient altitude: select other fuel tank, turn auxiliary fuel pump on, adjust mixture, and check magnetos. A note in the handbook stated: "The most probable cause of engine failure would be loss of fuel flow or improper functioning of the ignition system." According to the Federal Aviation Administration Airplane Flying Handbook, familiarity with and adherence to procedures developed by the manufacturer is key to managing emergency situations.