CEN20LA197

A fuel injection system leak at or near the No. 3 cylinder that resulted in a partial loss of engine power during cruise flight.

The pilot was conducting a ferry flight after the engine was disassembled, inspected, and reinstalled following a wheels-up landing incident that occurred a few months before the accident. About 51 minutes after takeoff the pilot declared an emergency with the air traffic controller due to a loss of engine power and stated that the airplane did not have sufficient altitude to land at the nearest airport. The pilot maneuvered the airplane to land in a nearby field, but he was unable to touch down before the end of the field where the airplane impacted trees a few feet above the ground in a level pitch attitude. Several witnesses reported seeing the airplane flying at a low altitude with a noticeable engine issue. Some of these witnesses reported hearing the engine "sputtering" or "misfiring" before the airplane descended out of their sightline behind trees. One witness reported seeing a “noticeable but faint, wispy, transparent film” trailing the aircraft and “white or light gray puffs” near the exhaust. According to recorded engine monitor data, during takeoff and initial climb, the fuel flow was 22 to 23 gallons per hour (gph), which was consistent with the airframe manufacturer’s engine performance charts at rated horsepower and manifold pressure. However, as the flight continued, the fuel flow increased to 29 to 30 gph, which was more than double the expected fuel flow for a leaned engine operating at 75% power during cruise flight. About 41 minutes into the flight, the No. 3 cylinder exhaust gas temperature (EGT) and cylinder head temperature (CHT) began decreasing and at a higher rate when compared to the other cylinders. Similarly, about 4 minutes before the accident, the No. 5 cylinder EGT/CHT also decreased and was inconsistent with the remaining four cylinders. Postaccident examination of the airplane revealed fuel streaks emerging from a louvered vent and access panel at the lower right side of the engine compartment, continuing aft along the lower right fuselage. There was no evidence of pooling or fuel streaking on the internal surfaces of the engine cowling. The fuel lines forward of the firewall exhibited no evidence of fuel leaks or obstructions, and all fractured fuel line fittings exhibited features consistent with impact related damage. The No. 3 cylinder head exhibited fuel stains on several cooling fins located on the forward-facing side of the intake port; however, there were no apparent cracks or fuel stains around the fuel injector nozzle or spark plug ports, and the No. 3 fuel injector line did not exhibit any damage or leaks. The No. 3 intake flange gasket compression faces were flattened around the inner diameter hole and there were no apparent kinks or tears. The No. 3 cylinder intake elbow and cylinder intake port flange face did not exhibit any fuel stains. The inter-cylinder baffle between the No. 3 and 5 cylinders exhibited prominent fuel straining and streaking. The remaining cylinders and engine components did not exhibit any visible fuel stains. The postaccident engine examination did not reveal a mechanical failure that would have prevented normal operation. Based on the excessive fuel flow and engine operation irregularities with the Nos. 3 and 5 cylinders during the flight, the fuel stains on the No. 3 engine cylinder near the intake, and the fuel streaks on the inter-cylinder baffle and the lower right side of the fuselage, the loss of engine power was likely due to a fuel injection system leak at or near the No. 3 cylinder.

An autopsy of the pilot was performed by the Franklin County Forensic Science Center, Office of the Coroner, Columbus, Ohio, which identified the cause of death as blunt force injuries of the head, and the manner of death was accident. No significant natural disease was identified during the autopsy. Toxicological testing completed by the Federal Aviation Administration’s Forensic Sciences Laboratory identified the sedating antihistamine diphenhydramine in the pilot’s urine but not in his blood. The gastric reflux medication famotidine was detected in his urine and in his muscle tissue and the asthma medication albuterol was detected in his lung tissue; these two medications are considered non-impairing. According to maintenance documentation, on February 5, 2019, at 3,861.1 total airframe hours, the installed Continental IO-470-K engine was removed and replaced with a factory rebuilt Continental IO-470-N engine, s/n 1036858, in accordance with supplemental type certificate (STC) No. SA5527SW. Additionally, a McCauley 3A36C434/80VEA propeller, s/n 190011, and McCauley C290D3/T35 propeller governor, part number (p/n) D20309-31, s/n 180680, were installed in accordance with STC No. SA00718CH. The last annual inspection of the airplane was completed on March 15, 2019, at 3,872.9 total airframe hours, at which time the engine had accumulated 11.8 hours since the factory rebuild. According to a Federal Aviation Administration (FAA) incident data, on February 3, 2020, the pilot inadvertently landed the airplane with the landing gear retracted at Ohio State University Airport (OSU), Columbus, Ohio. According to maintenance logbook documentation, after the wheels-up landing, the Continental IO-470-N engine, s/n 1036858, was shipped to Continental Services, Fairhope, Alabama, to be disassembled, inspected, and repaired for any propeller strike damage. After the engine was inspected, it was reinstalled on the airplane on May 22, 2020, at 4,056.8 total airframe hours, by the Ohio State University Airport certified repair station with a new McCauley 3A36C434/80VEA propeller, s/n 191236, and an overhauled McCauley C290D3-R/T35 propeller governor, s/n 180680. Postaccident review of recorded engine data revealed that on May 22, 2020, following the engine/propeller installation, the engine was run at least twice, accumulating about 10.8 minutes. The first engine run was 9 minutes in duration and included a fuel flow of 22.3 gph during an evident max power cycle. The second engine run was about 1.8 minutes in duration and did not appear to include a max power cycle. A review of the engine data for both test runs did not reveal any anomalies, and the maximum fuel flow during the first test run was consistent with the manufacturer’s specification of 22 gph for the engine at rated power. On May 27, 2020, at 4,057 total airframe hours, the damaged flaps were removed, and a serviceable pair of flaps were installed by a mechanic representing Plane Care, LLC, a certified repair station at Hagerstown Regional Airport (HGR), Hagerstown, Maryland. The mechanic disabled the flaps in the up position by pulling and collaring the flap circuit breaker. The landing gear was disabled in the extended position by pulling and collaring the landing gear circuit breaker. On May 27, 2020, the FAA issued a ferry permit for the airplane to be flown from OSU to HGR where additional airframe repairs were to be completed. At the time of the accident, the airframe total time was about 4,058.1 hours. The engine had accumulated about 197 hours since the factory rebuild and 1.3 hours since it was reinstalled on the airframe after the propeller strike inspection. Figure 3 – Engine Monitor Data During Engine Test Run on May 22, 2020 The airplane wreckage was at the edge of a field located about 3 nautical mile northeast of CDI, as shown in figures 4 and 5. There was no evidence that the airplane's wheels contacted the ground before the airplane flew into the trees at the eastern edge of the field on an east heading. Based on the damage to the trees and the airplane, the airplane impacted the trees a few feet above ground level in a level pitch attitude, as shown in figure 6. Fuel was present in both main fuel tanks and the fuel filter assembly, and there was no water or particulate matter observed in fuel samples recovered from both main fuel tanks. The fuel selector valve handle was found in the left main tank position. The fuel selector valve functioned as designed when tested. About 16 gallons of fuel remained in the fuel system when the airplane was recovered from the accident site. Visual examination of the fuselage’s exterior revealed fuel streaks emerging from a louvered vent and access panel at the lower right side of the engine compartment, and continued aft along the lower right fuselage, as shown in figures 7-11. There was no evidence of fuel pooling or streaking on the internal surfaces of the engine cowling, but there were a few rivet bucktails that exhibited fuel staining. The fuel lines forward of the firewall exhibited no evidence of fuel leaks. All fuel lines from the firewall to the fuel manifold were clear of obstructions when air was blown through them. All fractured fuel line fittings exhibited features consistent with impact related damage. There was no damage, debris, or obstructions to the fuel manifold, stainless steel injector lines, or fuel injector nozzles Nos. 1-4 and No. 6. The No. 5 fuel injector nozzle exhibited impact related damage but appeared clear of debris. The No. 3 cylinder head exhibited blue fuel stains on several cooling fins located on the forward-facing side of the intake port, as shown in figures 12-13. There were no apparent cracks or fuel stains around the fuel injector nozzle or spark plug ports. The inter-cylinder baffle between the No. 3 and 5 cylinders exhibited prominent fuel straining and streaking, as shown in figure 14. The intake flange gasket compression faces were flattened around the inner diameter hole and there were no apparent kinks or tears. The No. 3 cylinder intake elbow and cylinder intake port flange face did not exhibit any fuel stains. The remaining cylinders and engine components did not exhibit any visible fuel stains. The postaccident engine examination did not reveal a mechanical failure that would have prevented normal operation. Figure 4 – Aerial Photograph Showing Accident Site Location (FAA Photo) Figure 5 – Aerial Photograph Showing Accident Site Location (FAA Photo) Figure 6 – Main Wreckage at Accident Site (AMF Aviation Photo) Figure 7 – Fuel Streaks on Lower Right Engine Cowl Figure 8 – Fuel Streaks on Lower Right Engine Cowl Figure 9 – Fuel Streaks on Lower Right Side of Fuselage (FAA Photo) Figure 10 – Fuel Streaks on Lower Right Side of Fuselage (FAA Photo) Figure 11 – Fuel Streaks on Lower Right Side of Fuselage (AMF Aviation Photo) Figure 12 – Fuel Stains on No. 3 Cylinder and Inter-Cylinder Baffle Figure 13 – Fuel Stains Near No. 3 Cylinder Intake and on Inter-Cylinder Baffle Figure 14 – Fuel Streaking on Inter-Cylinder Baffle Between Cylinders Nos. 3 and 5 On May 27, 2020, about 1458 eastern daylight time, a Beech 35-A33 airplane, N123JB, was substantially damaged when it collided with trees during a forced landing near Cambridge, Ohio. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 ferry flight. According to airplane track data, at 1403:43, the airplane was established in a climb after it departed from runway 27L at Ohio State University Airport (OSU), Columbus, Ohio. The airplane flew to the west before it entered a climbing right turn to a northeast course. The airplane continued the climb to 3,000 ft mean sea level (msl) before it turned to an east-southeast course, as shown in figure 1. The airplane then climbed to a final cru