Accident Details
On April 16, 2023, at about 1010 Pacific daylight time, a Piper PA-28-180, registration N8376W, was substantially damaged in an accident near Riverside, California. The pilot and one passenger were not injured; a second passenger sustained minor injuries. The airplane was operating as a personal flight under Title 14 Code of Federal Regulations Part 91.
According to the pilot, after conducting an engine run-up and carburetor heat function checks, he switched to the left fuel tank and taxied for departure. After taxiing to runway 27 at Riverside Municipal Airport (RAL), Riverside, California, he waited for a takeoff clearance from air traffic control.
Following takeoff, during the initial climb at about 1,000 ft above ground level, the engine sputtered and then regained power. The pilot verified the mixture was full rich, the fuel pump was on, the left fuel tank was selected, and the magneto switch was on both. Shortly thereafter, the engine sputtered a second time and then lost total power. The pilot initiated a forced landing to a nearby field ahead of the airplane's position. During the off-airport landing, the airplane struck terrain and came to rest upright about 2 miles west of the departure end of runway 27.
Postaccident Examination
Postaccident examination of the engine revealed that when the crankshaft was rotated by hand using the propeller, continuity was established throughout the engine and valvetrain. Thumb compression was obtained on all cylinders. An alternate fuel source was plumbed to the right-wing fuel inlet port and the engine was run. The fuel source was then removed and reattached to the left-wing fuel inlet port, and the engine was run again successfully.
Weather Conditions
At 0953, the weather reported at Riverside Municipal Airport included a temperature of 16°C and a dewpoint of 9°C. The calculated relative humidity at this temperature and dewpoint was approximately 65%. Review of the icing probability chart contained in Federal Aviation Administration (FAA) Special Airworthiness Information Bulletin CE-09-35 revealed that the weather conditions at the time of the accident were “conducive to serious icing at glide [idle] power.”
According to FAA Advisory Circular 20-113, “To prevent accidents due to induction system icing, the pilot should regularly use [carburetor] heat under conditions known to be conducive to atmospheric icing and be alert at all times for indications of icing in the fuel system.” The circular recommended that when operating in conditions where the relative humidity is greater than 50%, “…apply carburetor heat briefly before takeoff, particularly with float type carburetors, to remove any ice which may have been accumulated during taxi and runup.” It also stated, “Remain alert for indications of induction system icing during takeoff and climb-out, especially when the relative humidity is above 50%, or when visible moisture is present in the atmosphere.”