Event Overview
On July 1, 2012, at approximately 1530 eastern daylight time, a Cessna R172K (registration N758JQ) made a forced landing at Greene Airport (4N7) in Greene, New York. The aircraft was operated by a private individual under 14 CFR Part 91 as a personal flight from Becks Grove Airport (K16) in Rome, New York, to Chenango Bridge Airport (1NK8) in Binghamton, New York. Visual meteorological conditions prevailed, and no flight plan was filed. The aircraft sustained substantial damage, but the sole occupant, the private pilot, was not injured. The flight originated from K16 at about 1450.
Sequence of Events
The pilot reported that during preflight, the engine oil quantity indicated 8 quarts (full). After takeoff, he climbed to 4,500 feet and proceeded toward the destination. About 25 minutes into the flight, after passing 4N7, the engine began running roughly, followed by a loss of power. He turned toward 4N7 and heard metallic grinding sounds as engine power continued to decrease. Unable to maintain altitude, he chose to land downwind on runway 07. The aircraft was about 100 knots at the threshold; near the runway midpoint, the main landing gear contacted the surface. The pilot pushed the control yoke to force the nose landing gear onto the runway in an effort to stop before running off the end of the runway and down a steep embankment. The airplane came to rest upright about three-quarters down the runway.
Examination Findings
A Federal Aviation Administration (FAA) airworthiness inspector examined the aircraft and found damage to the lower portion of the firewall and a compression wrinkle on the left lower fuselage skin aft of the firewall. Examination of the engine revealed that the head of the No. 3 cylinder assembly had separated from the barrel, which remained secured to the engine crankcase. The No. 3 cylinder and piston were retained for further examination.
The NTSB Materials Laboratory examined the No. 3 cylinder and piston. The barrel was fractured where it intersected the cylinder head, though the threaded end of the barrel remained within the head. Corrosion was observed on and between the cooling fins of the cylinder head, along with protruding and crater-shaped blisters. Paint covered the protruding blisters and many crater-shaped blisters. The fracture surface, after cleaning, showed two areas of relatively flat surfaces with curving crack arrest lines consistent with fatigue, both originating from corrosion pits on the outer surface.
Maintenance History
There was no record that the No. 3 cylinder had been replaced since the airplane was manufactured in 1979. In 1986, the engine was repaired, which involved removal of the cylinders and replacement of components. In 1987, engine horsepower was increased from 195 to 210; no modifications to the engine powertrain were necessary. The engine was last inspected in accordance with a 100-hour inspection on November 23, 2011. During that inspection, differential compression testing of the cylinders was performed at 80 psi; the No. 3 cylinder held 76 psi. The engine had accrued about 9 hours since that inspection at the time of the incident, and the airframe total time was reported as 1,358 hours. The engine manufacturer recommends overhaul every 1,500 hours or 12 years, but the owner reported the engine had not been overhauled since installation. Because the aircraft operated under 14 CFR Part 91, the owner was not required to follow the manufacturer's recommendation.