CIRRUS DESIGN CORP SR22T

Full Narrative

On March 11, 2022, about 1605 central standard time, a Cirrus SR22T airplane, N164CP, sustained substantial damage when it was involved in an accident near Minot, North Dakota. The pilot and one passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that he was on a 1.5-hour cross-country flight from Fargo, North Dakota. Minot International Airport (MOT), Minot, North Dakota was his destination. About 50 miles from MOT, the engine began to run rough. The pilot troubleshot the rough engine and initially concluded that there was an issue with the magneto. About 10 - 15 miles from MOT, the pilot perceived that the other magneto started to run rough. The No. 6 engine cylinder temperature began to rise, and the engine continued to run rough. The No.6 cylinder then “dropped offline,” followed by the Nos. 2 and 4 cylinders. The engine was still running, but the pilot could not maintain enough altitude to land at MOT, so he executed an emergency landing in a field.
The pilot landed the airplane in a snow-covered field about 2 miles from MOT. The airplane came to rest upright with the nose landing gear collapsed. Examination of the airplane revealed substantial damage to lower structural portion of the engine firewall. Engine oil was present on the belly of the airplane. The airplane was secured by a Federal Aviation Administration (FAA) inspector at MOT. The engine was removed and shipped to Continental Engines in Mobile, Alabama, for detailed examination.
Downloaded engine monitoring data showed the No. 6 cylinder dropped offline, followed by the Nos. 2 and 4 cylinders, which was consistent with the pilot statement. The data also showed that during the cruise portion of the accident flight, the engine manifold pressure was about 30.6 inches of mercury, and the fuel flow was about 19.6 gallons per hour. According to the airplane flight manual, leaning of the engine was to be accomplished by either leaning until the target fuel flow displayed on the engine monitor was achieved, or by monitoring the turbocharger inlet temperature and leaning until the temperature was 50° to 75° on the lean side of the peak value. The recorded data did not reveal the target fuel flow; however, the flight manual indicated a normal fuel flow of 18.3 gallons per hour with the airplane at 6,000 ft altitude and 30.5 inches of mercury.
Detailed teardown examination of the engine revealed various degrees of pitting damage to all six pistons heads. The most significant damage was found on the No. 2, 4, and 6 pistons, with the No 6 piston showing melting damage. The connecting rods exhibited thermal damage and the oil sump and oil filter contained aluminum particles. The fuel distribution spider valve and the fuel injectors were found normal and not obstructed. The crankshaft and main bearings exhibited a slight amount of lubrication distress. The extent of damage found at the No. 6 piston was consistent with the lubrication distress found in the engine. The remaining internal engine components exhibited normal operating signatures.
A review of the engine maintenance records did not reveal any uncorrected defects.