Accident Overview
On October 9, 2016, at about 1050 central daylight time, a Cessna 182T, registration N65903, was substantially damaged during a forced landing in a field near Toone, Tennessee. The private pilot was not injured. The flight originated from Destin Executive Airport (DTS), Destin, Florida, at about 0730, and was destined for McKeller-Sipes Regional Airport (MKL), Jackson, Tennessee. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed.
Pilot Report
The pilot reported that while cruising at 4,000 feet mean sea level and nearing the destination, an instrument panel warning sounded and the oil pressure indicator was in the red arc, though the engine ran smoothly. The pilot began to look for alternate landing sites and notified air traffic control (ATC) of the abnormal indication. ATC approved a direct course to the destination airport. Minutes later, a light "clanging" noise was heard from the engine, and the pilot informed ATC of an engine problem. The controller advised of a private airstrip 5 miles west. The pilot attempted to divert, but the noise grew louder and the engine lacked power to reach the airstrip. The pilot executed a forced landing in a field, where uneven terrain collapsed the nose landing gear.
Examination
A Federal Aviation Administration (FAA) inspector examined the airplane and found damage to the firewall. The No. 3 cylinder had failed catastrophically, with oil on the exterior of the engine and exhaust system near that cylinder. The No. 3 cylinder exhaust valve was stuck closed. The cylinder was sent to the NTSB Materials Laboratory. Examination revealed fractures of the rocker arm shaft bosses, bushings, and exhaust valve keeper. The rocker arm cover was fractured and bent outward. Fracture surfaces showed overstress features with no pre-existing damage like corrosion or fatigue. The stuck exhaust valve had deposits up to 0.006 inches thick.
Aircraft Information
The four-seat, high-wing, fixed-tricycle gear airplane was manufactured in 2004, powered by a Lycoming IO-540, 230-horsepower engine. The most recent annual inspection occurred on July 12, 2016, at which time the engine had 2,188.6 hours since new. The aircraft accrued 79.8 hours after that inspection, totaling 2,268.4 engine hours at the accident. The manufacturer recommended overhaul at 12 years or 2,000 hours, whichever occurred first.
Engine Data
A review of the engine data plot for the flight revealed that the No. 3 cylinder's exhaust gas temperature and cylinder head temperature were about two-thirds below those of the other five cylinders throughout the approximately 3-hour cruise portion of the flight.