Cirrus Design Corp SR22 N879CD accident near Lexington, South Carolina

Probable cause

A loss of engine power due to a shift of the No. 3 main journal bearing, which resulted in blocked oil ports that restricted oil to the engine’s internal components and a subsequent catastrophic engine failure.

NTSB analysis

The pilot reported that during cruise flight the oil annunciator light illuminated, the oil pressure decreased to zero, and the engine tachometer neared its maximum limit. Soon thereafter, the engine lost power. During the forced landing, the pilot activated the whole airplane parachute system at an altitude of about 2,000 ft above ground level. The airplane descended via the parachute and landed upright in a lake. The pilot and passenger were able to swim to shore and were not injured. The airplane’s fuselage and left elevator were substantially damaged during the landing.

Postaccident examination of the engine revealed that all of the crankshaft connecting rod journals showed evidence of lubrication distress. Additionally, the No. 3 main journal bearing shifted, resulting in the blockage of the oil ports and elongation of the crankcase lock slot. The No. 6 connecting rod bearing was fused to the crankshaft journal. The No. 1 cylinder rod bearings were fused together on the crankshaft, and the bearing surface was smeared and torn. The bearing metal melted and re-solidified along the edges.

It is likely that the shift of the No. 3 main journal bearing blocked the oil port and restricted oil to the engine and propeller, resulting in destruction of the bearing of the No. 6 cylinder. This likely resulted in the fracture of the connecting rod, breach of the crankcase, and the catastrophic failure of the engine. The engine overspeed reported by the pilot is consistent with a loss of oil pressure to the propeller governor, which would have lowered the blade pitch and increased engine rpm.

Review of maintenance logbook records revealed the No. 2 cylinder was replaced about 500 hours before the accident flight, at which time the engine had accumulated about 2,420 hrs. It is possible that the crankcase thru bolts were incorrectly torqued after the No. 2 cylinder change about 500 hours before the accident flight, which could have resulted in a shift of the No. 3 main journal bearing.

Text from the NTSB. Open the NTSB docket for ERA22LA109 for the full record.