What happened
On January 21, 2024, at approximately 1815 CST, a Cessna 2-10D, registration N3857Y, was involved in an accident near Paris, Tennessee. The aircraft was being operated as a Part 91 instructional flight, with a flight instructor acting as a safety pilot for a student working toward an instrument rating.
While cruising at 6,500 feet MSL, the pilot reported hearing a loud bang, followed by violent shaking of the aircraft and oil accumulating on the windscreen. The flight instructor took control of the aircraft and diverted to Henry County Airport (PHT). During the subsequent forced landing, the main landing gear struck the airport perimeter fence, causing the airplane to nose over. The accident resulted in no injuries to the crew, but the aircraft sustained substantial damage to the engine firewall and both wings.
The investigation
Post-accident examination of the engine identified a five-inch hole in the top of the crankcase between cylinders No. 3 and No. 4. Investigators found two quarts of oil in the oil reservoir. While cylinders No. 5 and No. 6 were removed for inspection, damage to the cylinder skirts of No. 3 and No. 4 prevented their removal.
In cylinder No. 4, the connecting rod was missing, and the connecting rod journal showed thermal discoloration and metal transfer. Fragments of the No. 4 connecting rod bolts, cap, piston, and piston ring were recovered from the oil sump along with bearing remnants.
Maintenance records indicated the last engine overhaul occurred on July 29, 1990. Recent cylinder replacements included cylinders No. 1, 3, and 5 on May 1, 2021, and cylinders No. 2, 4, and 6 on February 24, 2022.