Introduction
On July 23, 2022, at approximately 1238 central daylight time, a Beech A35, registration N8466A, was substantially damaged in an accident near Centralia, Illinois. The pilot sustained serious injuries, and the passenger was fatally injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight Details
According to the pilot, he had purchased the airplane in April 2022. The flight departed from Marshall County Airport (C75) in Lacon, Illinois, with the fuel selector positioned to the left tank. About 1 hour and 13 minutes into the flight, while at a cruising altitude of 6,500 feet mean sea level on a southerly heading near Centralia Municipal Airport (ENL), the pilot switched the fuel selector to the right tank. He reported that he did not trust the wobble pump mechanism and found it difficult to feel the detents in the selector valve, noting that it was possible the valve was not fully engaged.
Accident Sequence
Approximately 4 to 5 minutes after switching the fuel selector, the engine lost total power without any sputtering or abnormal indications. The engine power dropped to 1,500 rpm, and engine and propeller noise decreased. The pilot realized they had overflown ENL and made a right turn to reverse course, intending to land on runway 18 with a left traffic pattern. He pumped the manual wobble fuel pump rapidly, but engine power was not restored. The airplane continued through the traffic pattern until it became too low with no viable landing area. Engine power then decreased further, and the airplane descended into terrain. The pilot later stated that, in hindsight, a straight-in approach to the opposite end of the runway with a slip would have been preferable.
Post-Accident Examination
Examination of the accident site revealed a 100-foot-long debris path beginning at a 50-foot tree and continuing on a true heading of about 265°. The main wreckage came to rest in a residential backyard above an in-ground swimming pool, approximately 0.5 nautical miles north of runway 18's threshold and 0.2 nautical miles left of the extended centerline. The fuselage was oriented on a heading of about 100°, and the engine was partially separated from the fuselage.
The right wing sustained leading-edge crush damage along most of its span, with a semicircular gouge containing leaves and small branches about 2 feet inboard of the tip. The left wing had leading-edge crush damage and paint transfer marks consistent with the pool's rim cap. Both fuel caps were secure and undamaged. Fuel recovery yielded approximately 15 gallons from the right tank and 2.5 gallons from the left tank. The flaps and landing gear were retracted.
Fuel System Findings
The fuel selector handle was found partially extended upward (pump position) and rotated toward the right tank position, but the fuel selector valve was in the left tank position. An electric switch mechanism designed to illuminate a warning light when the handle is disengaged was found unattached from the selector valve/pump mechanism and stored in a cockpit map pocket. A 1969 Federal Aviation Administration airworthiness directive (AD 69-18-01) required either the installation of this switch and warning light or replacement of the mechanism with separate controls.
Further examination at a salvage facility confirmed flight control continuity. The fuel selector valve/wobble pump assembly, when the handle was fully down, rotated smoothly with detents and an audible click for each position. The valve operated normally with compressed air, and the wobble pump functioned properly when tested with fuel. The fuel filter screen was clean. Both fuel tank bladders appeared intact, and vent lines were clear except for a crushed section on the left wing leading edge. The left fuel tank finger screen was pulled from the tank toward the fuselage and was debris-free. The right tank finger screen was inaccessible. All engine controls, propeller control, and fuel lines remained attached, and the engine showed no anomalies that would have precluded normal operation.