Accident Overview
On August 10, 2023, about 2230 eastern daylight time, a Cessna C175, registration N7117M, was substantially damaged in an accident near Wetumpka, Alabama. The private pilot, the sole occupant, was not injured. The airplane was operating under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Flight Sequence
The pilot reported that during a flight to Shelby County Airport (EET) in Alabaster, Alabama, the airplane operated without issues until it suddenly shuddered and smoke began emanating from the engine compartment into the cockpit. The pilot recalled passing a private airfield and elected to divert and land there. While en route to the private field, the propeller intermittently stopped and restarted rotating. Upon locating the paved runway, the pilot initiated a series of 360° turns to lose altitude and reduce airspeed. During the second turn, the pilot noticed flames and sparks emitting from the engine area. After completing the final turn, the airplane's airspeed increased to approximately 130 mph and slowed to 110 mph near the runway midpoint. Concerned about potential injuries from colliding with trees at the runway's end, the pilot decided to go around and land in the opposite direction. The pilot applied full throttle and a full-rich mixture, maneuvering right of the field to avoid houses, then initiated a left turn back toward the runway. Midway through the turn, the propeller stopped rotating and the airplane began losing altitude. The pilot leveled the wings and pulled back on the yoke to a near-stall attitude, dragging the tail through the trees to reduce speed. The airplane slowed, and the fuselage came to rest atop the trees before descending through the branches and coming to rest on the ground.
Post-Accident Examination
A Federal Aviation Administration inspector reported that both wings and the fuselage were substantially damaged. The right wing's leading edge sustained impact damage; its fuel tank was breached and contained no fuel. The left-wing fuel tank was undamaged and contained an unquantified amount of fuel. No contamination or obstructions were found in the fuel system. Examination of the engine revealed a breach in the crankcase around the No. 3 cylinder. A deformed connecting rod was recovered near the nose landing gear after the airplane was removed from trees; its end cap was not recovered. The crankshaft journal exhibited heavy mechanical damage. An unquantified amount of oil residue was found in the engine cowling and on the airframe. The wreckage was subsequently sold as salvage without prior coordination with the FAA or NTSB and was not available for further detailed examination.
Maintenance Records
A review of the airplane’s maintenance logbooks documented removal and repair of the No. 5 and No. 6 cylinders completed on July 12, 2022. However, the maintenance invoice for that entry documented work on cylinders No. 1 and No. 2. In a telephone conversation, the pilot/owner stated that to his knowledge, the airplane’s previous owner had recently replaced "the back two cylinders," and he believed the engine damage or failures observed during the accident flight were related to one of those cylinders. He was unable to reconcile the discrepancies between the logbooks and invoices. The repair facility that performed the maintenance work also could not provide additional information regarding the discrepancies.