ERA24LA311

The pilot reported that he departed with 32 gallons of fuel onboard. About 2.5 hours after departure, the engine exhibited a momentary loss of power. He momentarily applied carburetor heat and noted that the fuel gauge indicated about one-quarter tank remaining. The power loss recurred several times before the engine lost power completely. The pilot was unable to restore engine power and performed a forced landing to a road. The airplane sustained substantial damage to the wings and fuselage. No fuel was observed at the accident site, and no fuel was recovered from the airplane during recovery or the postaccident examination. With the right wing positioned to correspond to a level-flight position, the single fuel gauge indicated about 1/4 tank with no fuel present and about 1/2 tank when 5 gallons of fuel was added, which demonstrated that the gauge substantially over-indicated the actual fuel quantity. The recorded temperature and dew point near the accident site was conducive to carburetor icing at glide and cruise power settings. Additionally, an unsigned copy of the last annual inspection showed that the airplane’s tachometer time recorded at the last annual inspection was greater than the tachometer time observed during the postaccident examination. Therefore, the airplane’s recent operating history and the amount of fuel consumed before the accident flight could not be fully determined. Fueling records showed that 25.1 gallons of fuel were added to the airplane on the day of the accident flight. While the pilot reported that the airplane departed with about 32 gallons of fuel onboard, the exact amount of fuel onboard at departure could not be verified. Based on data from the engine manufacturer’s operator’s manual, the engine would have consumed between 22 and 25 gallons of fuel for the 2.5-hour flight (not including fuel used for startup, taxi, takeoff, or climb). Given this information, fuel should have remained onboard if the departure fuel quantity reported by the pilot was accurate. However, no fuel was observed at the accident site or during the postaccident examination, and examination of the fuel system revealed no evidence of fuel leakage. Postaccident testing also demonstrated that the airplane’s single fuel quantity gauge substantially over indicated the actual fuel quantity. Although carburetor icing conditions existed and could have contributed to the reported intermittent power losses, the available evidence indicates it is most likely that the pilot’s assessment of the fuel quantity onboard before departure was likely inaccurate and the airplane subsequently exhausted its supply of fuel.

On July 21, 2024, about 1933 eastern daylight time, a Champion 7ECA airplane, N9581S, was substantially damaged when it was involved in an accident near Beaufort, North Carolina. The commercial pilot received minor injuries and the passenger was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that at the time the airplane departed from Horse Feathers Airport (53VA), Midland, Virginia, destined for Michael J. Smith Field Airport (MRH), Beaufort, North Carolina, there were about 32 gallons of fuel onboard. About 2.5 hours after departure, the pilot reported a momentary loss of engine power. He momentarily applied carburetor heat and noted that the fuel gauge indicated about one-quarter tank remaining. The power loss recurred several times before the engine lost power completely. The pilot was unable to restore engine power and performed a forced landing to a road. During the landing, the left wing struck a pole, and the airplane came to rest inverted about 3 miles northwest of MRH. Fuel records obtained during the investigation showed that 25.1 gallons of fuel were dispensed to the airplane on July 21, 2024, before the accident flight. The records also indicated that 32.4 gallons of fuel were dispensed to the airplane on July 17, 2024. The quantity of fuel onboard the airplane at the time of departure for the accident flight could not be independently verified. An FAA inspector examined the airplane at the accident site and observed that the airplane’s left wing was partially separated and the firewall was separated from the fuselage. The airplane sustained substantial damage to its wings and fuselage. The inspector reported that no fuel odor was observed at the accident site and no fuel was recovered from the airplane. The airplane was recovered to a secure facility, and a postaccident examination was conducted. The left and right fuel tanks were visually inspected with no breaches or fuel staining observed. Both fuel caps remained attached to their receptacles with their vents in the forward position. No anomalies were noted to the fuel cap seals, and the fuel vents were clear of obstruction. The gascolator bowl was separated and corrosion was noted on the filter screen. The fuel lines were fractured at the firewall area. The airplane’s fuel quantity gauge was mounted in the right wing fuel tank. There was no fuel gauge for the left wing. With the right wing positioned to correspond to a level flight position, the fuel gauge indicated about 7/32 with no fuel present. The fuel gauge indicated about 15/32 when 5 gallons of fuel were added. There were no leaks observed during a leak check of the fuel tanks. The engine remained attached to the engine mount. The throttle, mixture, and carburetor heat control cables remained attached to their respective mounts and were cut at various locations by recovery personnel. The carburetor remained attached to the engine and itsfuel inlet screen was clear of debris. Disassembly of the carburetor revealed no anomalies to its internal floats and components, and no fuel was observed in the bowl. Both magnetos remained attached to the engine and produced spark from their ignition towers during hand rotation of their gears. The sparkplug electrodes were gray in color and exhibited normal wear when compared to the Champion Check-A-Plug card; oil was observed on the top and bottom sparkplug electrodes of the No. 2 cylinder. Oil was observed within the oil sump, and the oil pump suction screen and oil filter media were clear of debris. During rotation of the attached propeller, crankshaft and valvetrain continuity were established, and compression and suction were attained on all four cylinders. There were no anomalies noted to the interior of the cylinders during examination via illuminated borescope. During the valvetrain continuity check, the four intake rocker arms produced less lift than the exhaust rockers. Removal of cylinder Nos. 2 and 4 revealed pitting of the camshaft followers and abrasion of the camshaft intake lobes. The airplane’s maintenance records were not made available throughout the course of the investigation. An unsigned copy of the last annual inspection was provided and showed that the annual inspection was completed on August 1, 2023. At that time, the engine had accrued 1,733.5 hours since major overhaul. The date of the engine’s last overhaul was unknown. Additionally, the tachometer time was recorded as 530.4 hours at the last annual inspection; however, during the postaccident examination, the tachometer showed 432.22 hours. The airplane’s flight manual was not observed during the examination or made available during the investigation. The recorded temperature and dew point near the accident site were about 82.4 F and 75.2 degrees F, respectively. On a carburetor icing probability chart, those temperatures were in the “icing – glide and cruise power” range. The airplane was equipped with a Lycoming O-320-A2B rated at 150 hp at 2,700 rpm, and a two-blade fixed-pitch propeller. The Operator’s Manual for the Lycoming O-320 Series engine indicated that at 2,350 rpm, 65% economy cruise, the fuel consumption would be 8.8 gallons per hour, and 10.0 gallons per hour at 2,450 rpm, 75% performance cruise. The total fuel consumption for the 2.5-hour flight at 8.8 gph would have been 22.0 gallons, and 25 gallons at 10.0 gph. Note that none of the calculations accounted for fuel used during start, taxi, runup, takeoff, or climb.