N1654MBoeing E75 · 1943

On September 30, 2021, about 1330 eastern daylight time, a Boeing E75, N1654M, was substantially damaged when it was involved in an accident near Nicholson, Pennsylvania. The pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

According to the pilot, while the airplane was at an altitude of 3,500 ft, the engine suddenly lost total power. He adjusted the throttle, mixture control, fuel valve controls, and carburetor heat, but the engine would not restart. Shortly afterward, the pilot noticed a strong smell of fuel. He then flew the airplane toward a nearby private airstrip. While setting up an approach to the runway, the pilot determined that the airplane would not reach the airstrip and performed a forced landing into trees that bordered the airport property, which resulted in substantial damage to the fuselage and wings.

Postaccident examination of the airplane found that the engine separated from the fuselage during the accident sequence and that fuel had been draining from the fuel line for “some time” after the accident occurred. A subsequent examination of the engine revealed that the carburetor’s rotating mixture actuating rod was difficult to rotate, and binding occurred as the actuating rod was rotated by hand. (The cockpit mixture control lever, through a linkage of push-pull tubes and control arms, rotates the mixture actuating rod.) The carburetor was then disassembled, and the actuating rod and the metering needle connected to the inner end of the rod were found bent, as shown in the figure below. (The metering needle attaches to an offset pin at the inner end of the actuating rod. As the rod rotates, the metering needle moves up or down [out of or into its seat] to control the amount of fuel that flows through the carburetor, setting the mixture.)

Figure. - Mixture actuating rod and metering needle.

The carburetor was otherwise undamaged. No impact marks, deformation, or other damage was found to the housing or bushings that surround the actuating rod and the seat for the metering needle. Other than the mixture actuating rod and the metering needle, no preimpact anomalies were found with the engine or the airframe fuel system components that would have precluded normal operation.

The front spark plugs were removed from the cylinders. Two had gray-colored electrodes, four had black-colored electrodes, and three of the electrodes were oil soaked.

A review of the maintenance records revealed no entries related to the carburetor or its controls during the preceding 4 years. During that time, the engine accumulated 81 hours total time.