Accident Overview
On December 17, 2009, at about 1435 Pacific standard time, a Cessna 172F, registration N8520U, sustained substantial damage following a loss of engine power and subsequent forced landing approximately 4 nautical miles southwest of Corona Municipal Airport (AJO) in Corona, California. The private pilot, the sole occupant, received minor injuries. The aircraft was operated by Fly Corona of Corona, California. Visual meteorological conditions prevailed for the local flight, which was conducted under 14 Code of Federal Regulations Part 91 without a flight plan. The flight departed AJO at about 1420.
Pilot Report
In a written statement to the NTSB investigator-in-charge, the pilot reported that before the flight he checked the fuel level and confirmed both fuel tanks were full. He also checked for water in the fuel system and found none. After takeoff, while established on right downwind abeam the runway numbers, he began his pre-landing checklist including carburetor heat and decreasing throttle. When he pulled the throttle out, the RPM dropped to 1,000. He intended to set 1,500 RPM, so he pushed the throttle in to reach 1,500 but got no response. Pushing further caused the engine to start to "bog" and "sputter," and it could not be increased above about 1,200 RPM. Shortly after turning onto base leg, the propeller slowed and stopped. Due to trees ahead, the pilot made a 180-degree left turn and landed in an open field described as "rough with loose gravel." During landing, the airplane impacted a fence and nosed over, resulting in substantial damage to both wings.
Pilot Experience
In an interview with a Federal Aviation Administration (FAA) inspector, the pilot stated that he had received 1.5 hours of flight instruction in the Cessna 172 before the accident flight, which was his only flight time in that make and model. He reported a total flight time of 90 hours.
Engine Examination
On December 21, 2009, an examination of the engine was performed by a certified FAA airframe and powerplant mechanic, supervised by an FAA inspector. The examination revealed no cracks in the cylinders or crankcase and no evidence of oil leakage. The crankshaft rotated freely by hand, and compression was noted on all cylinders. Spark plugs appeared normal with no fouling. Magnetos produced spark on all ignition leads with no abnormalities. Fuel tanks were sumped three times with no water found. The gascolator filter/screen was clean and free of debris. Positive fuel flow was noted with the fuel selector in all ON positions (Left, Right, and Both). The fuel line from the carburetor contained no blockages. On December 22, the carburetor top was removed, revealing a small amount of fuel with no water or particles.
Maintenance Records
Maintenance records indicated the engine's most recent 100-hour inspection was on October 23, 2009, with 1,164 hours since major overhaul and total tachometer time of 4,398.6 hours. The most recent annual inspection was on July 10, 2009, at a total airframe time of 8,498.61 hours.
Weather Conditions
At 1456, the Automated Surface Observing System (ASOS) at AJO reported wind from 150 degrees at 5 knots, visibility 10 miles, clear sky, temperature 24°C, dew point -1°C, and an altimeter setting of 29.99 inches of Mercury. Atmospheric conditions were not conducive to carburetor ice formation.
Determination
The reason for the reported loss of engine power could not be determined.