ERA25LA226

The pilot reported that as he descended toward the destination airport, about 35 to 40 miles out, the engine “stuttered.” He switched the fuel tanks, put the mixture in the full rich position, and the engine returned to normal. About 3 to 4 miles from the destination airport, the engine stuttered again and “went almost idle.” He again switched the fuel tanks and ensured that the mixture was full rich, but the engine did not regain power. He declared an emergency and requested to land on the nearest runway. He realized he would not be able to make it to the runway, so he turned left toward a cemetery and attempted a forced landing; however, the airplane impacted trees and came to rest nose down in heavy vegetation. Postaccident examination of the airplane revealed that 3 gallons of fuel remained in the left fuel tank, which was equal to the unusable quantity for the airplane’s individual fuel tanks. The right fuel tank contained 10 gallons. The examination also revealed no evidence of any preimpact mechanical malfunction or failure that would have precluded normal operation. Additionally, a partial-power engine test run was performed using the airplane’s fuel system with no anomaly found. An engine monitor was recovered from the airplane and a review of the data revealed that, based on the assumption that the pilot started the flight with the left fuel tank selected and that there were 77 gallons of fuel onboard at takeoff, the pilot switched the fuel tanks a total of 7 times, resulting in about 13 gallons of fuel being consumed from the right fuel tank and about 32 gallons of fuel being consumed from the left tank. Based on this calculation, and the 3 gallons of fuel recovered from the left fuel tank after the accident, it is likely that there was only unusable fuel remaining in the left wing fuel tank when the engine lost power. Additionally, the right fuel tank would have contained at least 7 gallons of usable fuel at the time the engine lost power. The pilot indicated that when he lost engine power, he did not attempt to restart the engine because he believed it was running but that it did not have any power. If the pilot had attempted to restart the engine with the right fuel tank selected, the engine likely would have regained power.

On June 10, 2025, about 1124 central daylight time, a Beech A36 airplane, N15PM, was substantially damaged when it was involved in an accident near Murfreesboro, Tennessee. The private pilot and a passenger were not injured. A second passenger was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, the flight departed from Douglas Municipal Airport (DQH), Douglas, Georgia, and was enroute to Murfreesboro Municipal Airport (MBT), Murfreesboro, Tennessee. While approaching MBT from the southeast at about 4,500 ft mean sea level (msl) and 35-40 miles from the airport, the pilot reported experiencing a “stumble” of the engine. He switched from the left fuel tank to the right fuel tank and pushed the mixture control in, which initially “cleared up” the problem. He continued toward the destination airport, but about 3-4 miles out and at 2,500 ft msl, the engine stuttered again and “went almost idle” and the pilot declared an emergency. He assessed that he would not be able to glide to MBT and, as a result, attempted to turn left toward a cemetery. He lowered the landing gear, pitched the nose up, and attempted to clear trees. The airplane contacted the trees before reaching the cemetery and came to rest nose down, suspended in vegetation. Postaccident examination of the wreckage revealed that the left fuel tank contained 3 gallons of fuel and the right fuel tank contained about 10 gallons of fuel. The fuel selector was observed to be on the right fuel tank position. The ignition key was observed on the both setting; the mixture control, propeller control, and throttle were observed to be in the full forward position. Postaccident examination of the engine revealed that it remained attached to the engine mount and the propeller remained attached to the engine crankshaft flange. The engine was not damaged, except for minor scuffing on the No. 6 engine rocker box cover. The top spark plugs were removed and the cylinders were inspected with a borescope . The top spark plug electrodes had normal wear and coloration consistent with lean engine operation. The cylinder combustion chambers and valve sets were unremarkable. The spark plugs were reinstalled to facilitate an engine test run. The left and right fuel tank bladders remained intact and were not breached. Tree impact damage just outboard of the right fuel tank fractured the fuel vent line. The engine was tested using the airplane’s fuel system from the fuselage, through the fuel selector valve, and out to the engine. The engine was started on the right fuel tank position and operated with no discrepancies. The engine was then operated on the Left fuel tank position and operated with no discrepancies. When the engine was started and idled the throttle was increased to 1,700 rpm, but could not be operated higher due to vibrations from the damaged propeller. Engine data from an electronic monitor were downloaded andreviewed. Data from the accident flight and engine test run were present. Review of the data for the accident flight showed that at 1123:35, fuel flow was recorded at 16.4 gallons per hour (gph) at 2,200 rpm, which was consistent with the previous 2 minutes of flight. At 1123:36, the fuel flow began to decrease, and reached 0 gph at 1123:47. Subsequent drops in engine speed, oil pressure, and exhaust gas temperature followed the drop in fuel flow, and were consistent with a loss of engine power. Fuel flow was not regained for the rest of the accident flight. A review of the fuel consumption during the accident flight was conducted using the engine monitor data and the Pilot’s Operating Handbook (POH) performance section. The airplane’s fuel system capacity was 80 gallons total, or 40 gallons per fuel tank, with 74 gallons of total usable fuel or 37 gallons of usable fuel per side. The pilot reported topping the fuel off the day before the accident flight and stated that the fuel onboard at takeoff was 77 gallons. The pilot stated that he was unsure which fuel tank he started the engine from initially, but he thought he started the engine on the left fuel tank based on how the airplane’s POH read. Given this information, the accident flight data showed that fuel was consumed from the left fuel tank from start up until climb, where a switch of the fuel tanks occurred for about 2 minutes (based on a brief fuel flow decrease observed at this and several other points throughout the data), before the pilot switched back to the left fuel tank. In total, the fuel selector remained on the left fuel tank for about 1 hour after engine startup, and since the engine start, it had consumed about 18 gallons of fuel. The fuel selector was switched to the right fuel tank in cruise and remained there for about 30 minutes, which consumed about 10 gallons of fuel before being switched back to the left fuel tank. The selector remained on the left fuel tank for about 45 minutes and consumed about 12 gallons. During the descent, the right fuel tank was selected for about 5 minutes and consumed about 2 gallons of fuel before being switched back to the left fuel tank. The engine ran on the left fuel tank for about 4 minutes and consumed about 2 gallons of fuel before the engine power was lost. The data shows one final fuel selector switch after the loss of engine power to the right fuel tank and fuel flow climbed slightly, but the engine did not regain power. Based on these calculations, 32 gallons of fuel were consumed from the left fuel tank and 13 gallons of fuel from the right fuel tank. The pilot stated that when he lost engine power, he did not attempt to restart the engine because he believed it was running but that it did not have any power.