Accident Details
On February 10, 2022, at 2006 central standard time, a Cirrus SR22T, registration N317KJ, sustained substantial damage during an accident near Lincoln, Nebraska. The pilot and a passenger were uninjured. The flight was conducted under Code of Federal Regulations Part 91 as a personal flight.
The pilot reported no anomalies during engine start, run-up, or takeoff. The initial flight was uneventful, with all gauges indicating within normal limits. At 10,000 ft mean sea level (msl) and about 60 nautical miles east of Lincoln Airport (LNK), the engine experienced a brief “stutter” and began running rough. The pilot contacted Omaha approach control, declared the engine roughness, and requested a diversion to Plattsmouth Municipal Airport/Douglas V Duey Field (PMV), located about 39 nm at 080° from LNK.
Engine Performance
The pilot received clearance to fly direct to PMV and descend to 4,000 ft msl. About 40 nm from LNK and at 8,000 ft msl, the pilot informed Omaha approach that the engine had smoothed out and requested to continue to LNK at 6,000 ft msl. As the flight progressed, the No. 3 cylinder head temperature indicated 0°F. Approximately 15 nm east of LNK, the engine began running rough again. The pilot requested a slow descent toward LNK and was cleared to 3,000 ft msl. About 12 nm from LNK, he was cleared for a visual approach to runway 17 and subsequently a landing clearance. During descent to 2,500 ft msl, the engine ran rough, oil pressure rapidly decreased, and indicated airspeed dropped. About 6 nm from LNK, the pilot advised LNK air traffic control that he could not reach the runway and would seek a field to land. He located a field, deployed the airframe parachute, and the airplane landed in the field, sustaining substantial damage to the fuselage.
Recorded avionics data indicated that around 1930, when the airplane was about 100 nm from LNK and 7 nm northeast of Schenck Field Airport, Clarinda, Iowa, at 10,000 ft, the No. 3 cylinder head temperature decreased to and remained about 210°F while other cylinder head temperatures were about 300°F. The No. 3 exhaust gas temperature correspondingly decreased to about 600°F while others remained about 1,300°F. These indications remained constant until about 2007:30, after which temperatures further decreased to the end of recorded data at 2009:55. The continuous temperature decrease corresponded to decreases in indicated airspeed and engine speed.
Postaccident Examination
Postaccident examination of the engine revealed that the No. 3 cylinder, opposite to the No. 4 cylinder, was attached and secured to its crankpin. The cylinder exhibited debris-related impact damage to an estimated 45° of the piston skirt bottom and nearest crank cheek.
The No. 4 cylinder connecting rod was detached from its crankpin at the connecting rod end. The end of the connecting rod was deformed, and its connecting rod bolts and cap were not intact. The No. 4 cylinder crankpin showed partial gouging along its circumference and radial impact-related deformation.
The No. 5 piston and its connecting rod were intact and secure. However, the crankpin end of the No. 5 piston connecting rod was not connected to its crankpin, and the connecting rod end was hammered into a rounded shape. The connecting rod cap was not intact. The No. 5 cylinder crankpin did not exhibit scoring or gouging like the No. 4 cylinder crankpin.
A deformed end of a connecting rod with both connecting rod bolts in place was found loose in the engine.
The engine oil sump contained metallic debris, consistent with internal engine component failure, and engine oil.
The airplane engine logbook showed that on June 30, 2021, at a Hobbs time of 887.7 and a flight time of 790.0 hours, the No. 5 cylinder (part number 658595A1, serial number AC18FB740) was removed and replaced with a new cylinder (part number 658815A3, serial number AC21CA785). No subsequent engine cylinder removals were recorded.