Accident Overview
On May 21, 2022, at about 1353 eastern daylight time, an Evektor-Aerotechnik Sportstar Plus, registration N503RK, was substantially damaged during an accident near Carroll, Ohio. The private pilot, the sole occupant, was not injured. The airplane was being operated under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Report
The pilot reported that the airplane had been parked for several months due to maintenance. After a thorough external inspection, he started the engine and let it run to confirm normal operation. Following engine checks, he taxied to the run-up area and prepared for takeoff. Shortly after departure, the engine failed to develop full power. The pilot leveled off to regain airspeed and observed a temporary increase of about 200 rpm. He turned north toward a practice area, but the engine again lost power. He then headed back toward the airport traffic pattern. While on the downwind leg, the engine stopped running, and the pilot broadcast a "MAYDAY" call. He performed a forced landing in a field adjacent to the airport. During the landing flare, the airplane touched down hard, causing the right main landing gear and nose landing gear to collapse.
Postaccident Examination
A Federal Aviation Administration inspector examined the airplane and found that the right horizontal stabilizer and fuselage were buckled. The engine was disassembled for inspection. When the No. 1 through No. 3 cylinder heads were removed, the pushrod O-rings were found incorrectly installed. The O-rings were crushed and partially disintegrated, with material present in the crankcase bore. The No. 4 cylinder head showed the intake pushrod tube O-ring extruding from the bore. No leaks were found in the oil or cooling systems. The crankshaft could not be rotated manually. After further disassembly, the No. 4 connecting rod was found separated from the crankshaft. The No. 3 piston exhibited scoring, and liberated pieces of pushrod O-rings were blocking oil ports that supplied the No. 4 connecting rod bearing.
Maintenance Records
Review of the maintenance logbooks revealed no recent engine work requiring cylinder head removal. The cylinders had been removed and reinstalled for repair on August 4, 2013, at a tachometer time of 480 hours. That event occurred 8 years and 10 months and 58.8 tachometer hours before the accident.