On May 27, 2021, about 1825 central daylight time, a Vans RV-8 airplane, N274CV, was substantially damaged when it was involved in an accident near San Angelo, Texas. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations personal flight. Shortly after takeoff, the airplane came to rest upright, with substantial damage to the fuselage and wings. The responding Federal Aviation Administration (FAA) inspector reported that the fuel tanks seemed empty but appeared to have been breached in the accident. The airplane had undergone maintenance with the installation of a Garmin G3 system, and the accident flight was the first flight after the installation. He also noted that the avionic shop drained about 40 gallons of fuel from the tanks and added the fuel back for calibration. The airplane was recovered to a salvage yard, where the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) conducted an examination. The top set of sparkplugs were removed from each cylinder, and the engine rotated by hand. Continuity through the valve train and to the accessory section was noted. The left and right magnetos were removed and, when rotated, produced a spark on each terminal. The fuel system was equipped with a fuel flow transducer located in the fuel line between the pressure side of the engine-driven fuel pump and carburetor (see figure 1). The addition of the fuel flow transducer was required to provide fuel flow reading on the new panel. Figure 1: “Red Cube” Fuel Flow Transducer The pressure side of the engine driven fuel pump outflow fitting had two fittings installed. The 3/8’s port was capped off with an AN929 fitting. The other port had a number 4 fitting installed in the fuel line (which ran to the fuel flow transducer – see figure 2 & 3). Figure 2: Fuel Line as it exited to the Engine Driven Fuel Pump Figure 3: Fuel Pump Fittings