Accident Overview
On May 2, 2020, at approximately 0930 Pacific daylight time, a Cessna 172N, registration N734NW, was substantially damaged in an accident near Sierra Sky Park Airport (E79) in Fresno, California. The pilot, who sustained minor injuries, was operating the airplane under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Account
The pilot reported that the airplane had recently undergone maintenance and that this was the third flight following those repairs. He planned to stay in the local area. During preflight inspection, he noted 28 gallons of fuel in the tanks and visually checked the fuel strainer for contamination, finding none. He estimated the wind at 9 to 10 knots straight down runway 30 (headwind). After initiating takeoff, when the airplane reached about 300 to 400 feet above ground level, the engine power began to fluctuate and subsequently remained at a low power setting. The pilot pitched the airplane to maintain 70 to 80 knots indicated airspeed. He prepared for a downwind landing on runway 12 and, realizing the airplane had excess energy, deployed the flaps and performed a forward slip maneuver. The airplane touched down about halfway down the runway, continued off the end, and went through a fence. It then passed over the two westbound lanes of a road and nosed over in the median.
Postaccident Examination
A postaccident examination was conducted on the airplane and engine. Rotating the crankshaft by hand using the propeller established rotational continuity throughout the engine and valve train. All intake and exhaust valve rocker arms moved equally. Thumb compression and suction were obtained on four of the six cylinders. Cylinders number 3 and 5 had very minimal thumb compression. A differential pressure gauge connected to cylinders 3 and 5 indicated compression loss ranging from 25 to 75 percent. After tapping the valve rocker arms with a rubber mallet, compression recovered to approximately 25 percent loss in the number 3 cylinder and 15 percent loss in the number 5 cylinder. An internal borescope examination of the engine cylinders revealed normal piston tops and cylinder sidewalls, with no evidence of foreign object ingestion.
Fuel System Examination
Examination of the fuel strainer revealed that the drain pull handle used for draining the strainer was inoperable. The drain valve cable was dirty and showed no evidence of frequent actuation, as the cable exhibited no signs of sliding in and out of the cable housing. After disconnecting the cable, the drain valve was opened manually without restriction. The fuel strainer bowl was removed, and the internal screen was free of debris. The fuel remaining in the strainer bowl was clear and bright.
Maintenance History
Review of the airplane's maintenance records showed that the engine had been disassembled and the carburetor and fuel strainer had been overhauled 1.9 hours before the accident flight.
Probable Cause
The investigation did not state a probable cause.