Primary finding
Probable cause
A partial loss of engine power for undetermined reasons.
Investigator assessment
Analysis narrative
During descent, after a short local flight, the engine lost partial power. The pilot advanced the throttle and turned on the carburetor heat; however, power was not restored to the engine. He performed a forced landing to a wet, grassy field. The main landing gear wheels locked up and the airplane contacted a tree stump during the landing roll. Although a review of the maintenance records revealed the airplane’s engine had not been overhauled in 24 years, exceeding the recommended engine overhaul time of 12 years, a postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The reason for the partial loss of engine power could not be determined.
Source record
Factual narrative
On February 28, 2022, about 1730 eastern standard time, a Cessna 152, N68218, was substantially damaged when it was involved in an accident near Madisonville, Tennessee. The pilot and passenger received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, after a normal preflight inspection, he departed with 20 gallons of fuel for a local flight. After a 30-minute flight, about 5 miles from the airport, he initiated a descent from 3,000 ft and slightly reduced engine power. About 10 seconds later, the engine rpm suddenly dropped to 900 to 1,000 rpm. He advanced the throttle and turned on the carburetor heat, with no effect on the engine. He performed a forced landing and touched down on a wet grassy field. During the rollout the main landing gear wheels locked up, the airplane hit a tree stump and came to a stop. According to the Federal Aviation Administration (FAA) inspector who responded to the site, the left wing was nearly separated at the wing root, and the firewall was bent. A detailed examination of the engine supervised by the FAA inspector confirmed crankshaft continuity. Compression and suction were observed on all four cylinders and a lighted borescope was used to view the interior of the cylinders and no anomalies were noted. The propeller was separated at the crankshaft flange. The carburetor was separated, the throttle cable remained partially attached. The magnetos remained attached to the engine, and spark was observed from all towers when rotated by hand. The oil suction screen and filter were absent of debris. According to the manufacturer’s maintenance manual, the engine should be overhauled every 12 years. Review of the maintenance logbooks revealed the engine had not been overhauled since 1998. The engine had accumulated 1,598 hours since the overhaul. Between the annual inspection in 2021 and the previous annual in 2017, the airplane accumulated 4 hours of flight time.