NTSB Factual Report

On July 31, 2001, at 1550 eastern daylight time, a Piper PA-28-180, N55205, was substantially damaged during a forced landing in New Milford, Connecticut. The certificated student pilot received minor injuries, and visual meteorological conditions prevailed at the time of the accident. No flight plan had been filed for the flight, between Waterbury-Oxford Airport (OXC), Oxford, Connecticut, and Orange County Airport (MGJ), Montgomery, New York. The student solo instructional flight was conducted under 14 CFR Part 91.

The student pilot reported that the airplane was in level flight, about 3,000 feet, with the engine operating at 2,350 rpm. The engine began to sound "louder" than normal. The student pilot checked his gauges, and noticed the oil pressure was "off". At the same time, he saw smoke coming out of the engine. The student pilot reduced engine power to idle and attempted to land the airplane in a field. The airplane overshot the field and struck trees.

According to a Federal Aviation Administration (FAA) inspector, there was a hole in the engine crankcase, in the vicinity of the #2 cylinder. There were seven quarts of oil showing on the oil dipstick, and there were no broken or loose oil lines or filter. The crankshaft turned freely until the propeller blades contacted the ground.

The Textron Lycoming O-360-A4A engine was subsequently examined by an air safety investigator from the manufacturer, under the supervision of the FAA inspector. According to the investigator's report:

"There was a hole in the upper left case between the number two cylinder lifter body boss, no other holes found in the case or sump areas. The removal of the number two cylinder was extremely difficult since the cylinder skirt had been bent outward due to the fact that the connecting rod had separated from the crankshaft and had outwardly bent the cylinder skirt. The connecting rod that contacted the crankshaft journal exhibited lateral scaring, heat signature, and peening. The piston, by means of the connecting rod, was moved the length of the cylinder barrel and the stroke was limited by the destruction of the cylinder skirt. The number two crankshaft journal displayed the same characteristics as the end of the connecting rod. Upon further examination of the engine, it was discovered that the number one cylinder connecting rod had separated from the piston. The cylinder was removed, with the same difficulty as the number two cylinder. The examination of this assembly revealed that the connecting rod was bent approximately 10 degrees at the base of the pin hole with the piston pin still in place. The top of the connecting rod displayed peen marks, as did the bottom interior of the piston. The piston could not be moved from the top of the cylinder. The connecting rod was loose on the journal with one hold-down nut missing. The opposite hold down bolt and nut were tight. The connecting rod exhibited rotational scratching, with no heat signature. Three of four connecting rod hold down nuts were recovered. The lipped surfaces of two of the nuts displayed no rotational scratch marks associate with contacting other metal surfaces; the third nut had such rotational scarring."

The operator reported that the engine had 6,036 hours of operation and 456 hours since overhaul, .

NTSB Probable Cause

Separation of the number two connecting rod for reasons undetermined.