WPR25LA027

The airplane was equipped with a four-cylinder, air-cooled, direct-drive, horizontally opposed, fuel-injected engine, rated at 215 horsepower at 2,700 rpm. A review of the maintenance records revealed that the airplane was maintained under the Cirrus 400-hour progressive inspection program until 2023. An entry dated January 29, 2024, stated that the airplane was no longer maintained under the Cirrus 400-hour progressive inspection program and that a 100-hour/annual inspection had been completed at an airframe total time of 1,509.7 hours. The flight instructor reported that the airplane had been purchased about 5 months before the accident. The flight instructor estimated that the airplane was about 230 pounds below maximum gross weight. On October 27, 2024, about 1712 mountain standard time, a Cirrus Design Corp. SR20 airplane, N27WF, was substantially damaged when it was involved in an accident near St. George, Utah. The flight instructor, student pilot, and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor stated that the purpose of the flight was to drop the passenger off in Provo, Utah, while also providing the owner/student with familiarization experience in the airplane. The flight instructor reported that, during the run-up, he noticed the left magneto was running rough with about a 150-rpm drop. Assuming spark plug fouling, he leaned the mixture for several minutes and then repeated the magneto check, which showed normal operation. Thereafter, they departed from runway 19, and the flight instructor noted that the airplane’s acceleration felt sluggish, which he attributed to the added weight. He stated that the airplane climbed normally to about 200 ft above ground level before it would no longer accelerate, although the engine sounded normal. The flight instructor stated that he cycled the throttle, adjusted the mixture, and confirmed that the flaps were at 50 percent. He reported that, despite those actions, the airplane did not accelerate. With rising terrain ahead, he banked left toward the airport. After realizing that the airplane would not make it back to the runway, he maintained a controlled descent to avoid a stall. During the off-airport landing on soft desert terrain, he flared aggressively to reduce ground speed. The left wing dropped and the airplane landed hard, which resulted in separation of the landing gear. The airplane then skidded and rotated about 180° to 270° before it came to rest upright. The occupants exited the airplane, and a fire ensued shortly thereafter. The airplane came to rest about 5 miles south of the airport. According to the flight instructor, the engine and propeller appeared and sounded normal during the accident flight but did not produce the expected thrust. He recalled that the boost pump was on, but he could not remember which fuel tank was selected because he had followed the checklist and switchedtanks after the run-up. He stated that the airbags did not deploy. Engine Data Recorder The airplane was equipped with an Appareo RDM-300 recoverable data module. The recovered file contained about 22 minutes of data, from 1651:12 to 1713:34, and included engine rpm, manifold pressure, fuel flow, calculated percent power, oil pressure and temperature, individual cylinder exhaust gas temperature (EGT) and cylinder head temperature (CHT), and airplane performance parameters. At 1654:00, the engine started and operated for about 6 minutes and 42 seconds. During a likely ground run-up, the engine speed increased to a maximum of 2,267 rpm. At 1700:42, the engine stopped. The data then recorded several short engine-start attempts before the engine restarted at 1704:45. During a second ground run-up, the engine speed increased to a maximum of 2,475 rpm, decreased to about 600 rpm, and then returned to about 2,200 rpm. At 1708:31, the manifold pressure increased to about 27 inHg, consistent with the application of takeoff power. The fuel flow increased to about 9 gph, and the engine speed increased to about 2,300 rpm. The engine speed increased gradually as the airplane accelerated and first exceeded 2,500 rpm about 36 seconds later. The airplane reached 70 knots indicated airspeed about 49 seconds after the increase in manifold pressure. The maximum recorded engine speed was 2,636 rpm, slightly below the engine’s rated speed of 2,700 rpm. After the engine speed exceeded 2,500 rpm, the manifold pressure remained between 26.8 and 27.0 inHg, the fuel flow remained between 9.2 and 9.7 gph, and the calculated percent power remained between 82% and 87%. The recorded engine parameters remained generally stable until about 1712:19, when the manifold pressure, fuel flow, and engine speed decreased during the final seconds of the accident sequence. A review of the recorded data did not identify an abrupt loss of manifold pressure, fuel flow, oil pressure, or combustion from an individual cylinder during the takeoff or flight. The engine did not attain its rated speed despite the manifold pressure remaining near 27 inHG, and the airplane accelerated slowly during the takeoff roll. The data was consistent with reduced available power or thrust during the takeoff and initial climb. Cirrus provided four previous flight recordings from October 21 and October 25, 2024. Two of the previous departures were from St. George Regional Airport and two were from Provo Municipal Airport. During the four previous takeoffs, the engine speed exceeded 2,600 rpm within 4 to 6 seconds after the initial increase in manifold pressure and then stabilized near 2,700 rpm. The manifold pressure stabilized between about 25.3 and 27.0 inHg, and the fuel flow stabilized between about 13.0 and 19.4 gph. The airplane accelerated to 70 knots indicated airspeed within 17 to 23 seconds. At 60 seconds after the application of takeoff power, the altitude had increased between about 219 and 323 ftabove the runway elevation. During comparable portions of the two previous St. George takeoffs, the average engine speeds were about 2,703 and 2,710 rpm, and the average fuel flows were about 17.3 and 19.4 gph. During the accident takeoff, the average engine speed was about 2,461 rpm and the average fuel flow was about 9.2 gph. The accident-flight EGT values averaged between about 1,457°F and 1,516°F, compared with about 1,264°F to 1,395°F during the previous St. George takeoffs. The CHT values during the accident takeoff were slightly higher than during the previous takeoffs but remained stable. Examination The postaccident examination revealed that the engine remained attached to the airframe by the engine mount and had sustained severe thermal damage from the postimpact fire. The accessory case housing and attached accessories, including the magnetos, fuel pump, vacuum pump, and oil filter, had been consumed by fire. Rotation of the crankshaft was precluded by thermal damage to the engine case and cylinders. The combustion chambers were examined through the spark plug holes with a lighted borescope. The combustion chambers and bottom spark plug electrodes remained mechanically undamaged, and there was no evidence of foreign object ingestion. The valves were intact and undamaged, and there was no evidence of valve-to-piston contact. Additional borescope examination through holes drilled in the top of the engine case allowed visualization of the connecting rods, crankshaft, and cam lobes. Investigators reported no evidence of lubrication deprivation or contamination. The crankshaft and connecting rods were free of heat distress. The roller tappet camshaft was intact, and each cam lobe exhibited its characteristic elliptical shape. The accessory gears, including the crankshaft gear, bolt, and dowel, were intact and exhibited no evidence of a preimpact malfunction. A majority of the fuel system was consumed by fire and could not be functionally examined.