Accident Sequence
On September 29, 2021, at about 1406 eastern daylight time, a Cessna 172S (N116SV) was substantially damaged during a forced landing near Port Orange, Florida. The flight instructor and student pilot were not injured. The airplane was operating as a Title 14 Code of Federal Regulations Part 91 instructional flight.
The instructor reported that earlier in the day, the student pilot flew from Massey Ranch Airpark (X50), New Smyrna Beach, Florida, to Gainesville Regional Airport (GNV), Gainesville, Florida, and performed an uneventful full-stop landing. After departing GNV to return to X50, the student pilot was at the controls. The airplane had adequate fuel, and the mixture was leaned after climbing to 3,500 ft mean sea level (msl).
Daytona Beach Approach Control cleared the flight to descend to 2,500 ft and then to 1,600 ft msl. While descending with power reduced to 1,900 rpm, the instructor noticed the airplane was 100 ft below the assigned altitude. The student pilot then reported a loss of engine power. The instructor took over, applied full throttle with no change in engine rpm, confirmed the mixture was full rich and the fuel selector on "both", and pitched for best glide speed (68 knots). The student pilot began the engine failure checklist.
The instructor advised the controller of the power loss, and the controller provided nearby airport information. Given the airplane's altitude and distance from those airports, the instructor chose an off-airport landing site. After touchdown, the nose landing gear contacted an object, causing the airplane to nose over. Substantial damage resulted to the left wing, vertical stabilizer, and the bottom and left side of the fuselage near the horizontal stabilizer.
The airplane was equipped with a Garmin G1000 multifunction display, but no pertinent data could be recovered because the installed firmware version did not store data.
Postaccident Examination
Postaccident examination of the engine revealed that rotation of the crankshaft did not rotate the camshaft. Removal of the accessory case showed the left crankshaft idler gear assembly, which is driven by the crankshaft gear and drives the camshaft, was out of position. Extensive damage was found in the area of the left crankcase that supports and secures the crankshaft idler gear shaft. The left crankcase, which receives the securing bolt on the lower portion of the gear shaft, exhibited extensive damage. The castellated nut securing the upper portion of the shaft to a stud in the crankcase was separated, and the bolt securing the lower portion was fractured. The right crankshaft idler gear shaft remained secured by two safety-wired bolts.
A photograph of the oil filter element showed non-ferrous particles. The owner/operator reported that maintenance personnel had not cut open the oil filter during each engine inspection while he owned the airplane.
The engine had been overhauled by a repair station in December 2010 and installed in the airplane several days later. It was removed in July 2011 for disassembly inspection due to a stuck valve and bent pushrods, then reinstalled on July 20, 2011, remaining in the airplane until the accident. The engine had accrued about 3,488 hours since its last inspection and oil change on June 25, 2021. No evidence allowed determination of engine time between that inspection and the accident.