Accident
On November 30, 2019, at about 1000 eastern standard time, a Yakovlev Yak 52, registration N52CY, was substantially damaged during an off-airport landing near Wrightsville, Georgia, after experiencing a loss of engine power en route. The flight instructor and private pilot, both aboard, sustained minor injuries. The aircraft was registered to and operated by the flight instructor under Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Waycross-Ware County Airport (AYS), Waycross, Georgia, at about 0915, and was destined for Kaolin Field Airport (OKZ), Sandersville, Georgia.
According to the private pilot, seated in the rear seat, the flight was the second day of a cross-country trip to move the recently purchased airplane from Florida to Tennessee. The previous day's flights and the accident flight's takeoff and cruise were normal until about 10 minutes from OKZ. While cruising at 3,500 ft mean sea level, a sudden heavy vibration from the engine lasted about 5 seconds, resulting in a complete loss of engine power. The pilot reported no prior indication of an engine problem before the vibration.
The flight instructor reported the same heavy vibration and loss of engine power. He noted that the vibration was so intense that an engine gauge fell from its position into the back of the instrument panel. He immediately took the flight controls and adjusted the throttle but received no engine response. After attempting an engine restart, he engaged the starter and observed that one propeller blade remained fixed in the airstream. The instructor then turned the airplane left to align with a long farm field. While on final approach at about 500 ft above ground, he extended the landing gear, causing the airspeed to decay rapidly and the descent rate to increase. The airplane entered the landing flare "out of airspeed," and shortly after the nose wheel touched down, the airplane nosed over and skidded to a stop.
Aircraft and Engine Examination
An FAA inspector who examined the airplane at the accident site reported that the airplane came to rest upside down. The fuselage, empennage, and wings sustained substantial damage. Flight control continuity was confirmed to all surfaces. Oil spray was observed on the underside of the fuselage. When the propeller was moved by hand, it was revealed that the engine had seized and would not rotate.
Further examination by an NTSB investigator found thick black oil present in the engine. The spark plugs were dark in color. The propeller blades sustained impact damage. Inspection of each cylinder with a lighted boroscope revealed that the cylinders were very dark in color and oil soaked. The No. 5 cylinder exhaust valve was damaged and had the appearance that the valve seat dropped into the cylinder. Metal pieces were also found inside the No. 5 cylinder.
Aircraft Information
According to FAA airworthiness and maintenance records, the 2-tandem seat former Soviet aerobatic trainer was manufactured in 1988 and powered by a Vedeneyev M14P nine-cylinder radial engine. The propeller was a wooden Vperod V530TA-D35. The most recent 100-hour inspection was completed on November 1, 2019, during which the engine oil and spark plugs were replaced. There was no mention of an inspection of the engine cylinders.
The flight instructor stated that the airplane had not flown for a "couple of years" prior to the 100-hour inspection and the repositioning cross-country flight.
Pilot Information
According to FAA airman records, the private pilot held ratings for airplane single- and multi-engine land and instrument airplane. He completed the FAA basic medical certificate course on October 21, 2019. His most recent flight review was completed on November 19, 2019. He reported a total flight time of 1,920 hours, with 4 hours in the accident airplane make and model. In the past 90 days, he reported 4 hours.
The flight instructor held an airline transport pilot certificate with a rating for airplane multi-engine land, a commercial pilot certificate with ratings for airplane single-engine land and sea, and glider, and a private pilot certificate for rotorcraft-helicopter. He also held a flight instructor certificate for airplane single- and multi-engine, instrument airplane, and glider. He did not hold a medical certificate. He reported a total flight time of 3,805 hours, with 4 hours in the accident airplane make and model. In the past 90 and 30 days, he reported 20 and 7 flight hours, respectively.
Weather
At 0955, the hourly weather observation at OKZ, about 12 nautical miles north of the accident site, included wind from 210° at 4 knots, visibility 10 statute miles, overcast ceilings at 3,100 ft above ground, temperature 16°C, and dew point 10°C.