On September 19, 2015, a CESSNA 150M (registration N714CW) was involved in an aviation accident near Mount Airy, MD. No fatalities were reported. Investigators recorded the probable cause as: The in-flight fatigue failure of the No. 4 cylinder barrel, which resulted in a total loss of engine power. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.
A Cessna 150M, N714CW, was substantially damaged after a precautionary landing in a cornfield near Mount Airy, Maryland, on September 19, 2015. The pilot was uninjured, and the accident was attributed to a fractured engine cylinder.
Accident Overview and Flight Details On September 19, 2015, at approximately 1200 eastern daylight time, a Cessna 150M, registration N714CW, sustained substantial damage during a precautionary landing in a field near Mount Airy, Maryland. The private pilot was not injured. The aircraft was operating under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and a visual flight rules (VFR) flight plan was filed for the flight, which departed Clearview Airpark (2W2) in Westminster, Maryland, at 1130 and was destined for Leesburg Executive Airport (JYO) in Leesburg, Virginia. ## Pilot Report and Emergency Sequence The pilot reported that 10 minutes after takeoff, at an altitude of 2,500 feet, the engine was not producing full power. The pilot monitored the situation and adjusted the flight path to position the aircraft over Davis Airport (W50) in Laytonsville, Maryland, in case a landing was required. The engine condition was described as “a little sluggish” and progressively worsened, becoming rough before losing more power. All engine instrument indications remained normal. The pilot declared an emergency and identified a field for landing. While circling to land, the pilot observed electrical wires on the approach end and elected to fly downwind for a landing in the opposite direction. During the turn to final, insufficient altitude prevented reaching the intended landing site, and the aircraft landed in an adjacent field planted with mature corn. As the aircraft settled into the corn, it touched down and flipped over. ## Aircraft and Engine Maintenance Records According to Federal Aviation Administration (FAA) airworthiness and maintenance records, the aircraft was powered by a Continental O-200-A, 100-horsepower engine, driving a McCauley metal two-blade fixed-pitch propeller. The pilot reported the engine had 3,567 hours total time and 1,800 hours total time since overhaul. The aircraft had accrued 15.7 hours since its last annual inspection on October 23, 2014. A Major Repair and Authorization form (OMB No. 2120-0020) indicated that four Superior-SA10200 series cylinders were installed on May 10, 1995, during the last engine overhaul. ## Weather and Site Conditions Carroll County Regional Airport/Jack B Poage Field (DMW) in Westminster, Maryland, was located about 8 miles north of the accident site. Weather recorded at DMW at 1230 included wind from 200° at 9 knots gusting to 14 knots, visibility of 10 statute miles, clear sky, a temperature of 27°C, a dewpoint of 17°C, and an altimeter setting of 29.96 inches of mercury. ## Wreckage Examination and Engine Findings An FAA inspector responded to the accident site and examined the wreckage. The aircraft and all major components were accounted for at the scene. Substantial damage was observed to the underside of the fuselage, where the nose landing gear was sheared off, along with damage to the firewall and engine mounts. Both wing spars were damaged, and the vertical stabilizer was bent. Additional damage was found to the No. 4 cylinder, and oil streaks were observed on the underside of the engine cowling and fuselage. The propeller was intact and undamaged. Subsequent detailed examination of the engine revealed that the No. 4 cylinder (part number SA10200) fractured at the barrel portion about 2 inches out from the engine case, completely separating from the bottom portion of the cylinder that remained attached to the case. The No. 4 piston was gouged and missing a large amount of material. A substantial amount of oil and metal fragments were discovered in the engine compartment. The No. 4 cylinder, piston, and wrist pin were removed and sent to the NTSB Materials Laboratory for additional examination. A microscopic examination of the upper fracture face revealed a dark thumbnail mark consistent with a fatigue crack that emanated from the outer surface of the barrel. The fatigue crack originated from a corrosion pit and propagated through the thickness of the barrel, extending about 2½ inches to each side of the fatigue origin area. The piston exhibited a rough texture on a slant plane typical of overstress separation.