ERA22LA309

The pilot departed and remained in the airport traffic pattern. While on the downwind leg, he applied carburetor heat then reduced power to 2,000 rpm. Abeam the approach end of the runway, he reduced power further, then turned onto the base leg, where he recognized that the engine had lost power. After turning onto final approach and realizing that the airplane would not reach the runway, he performed an off-airport landing in a field, resulting in nose-over and substantial damage to the left wing, fuselage, and aft empennage. Postaccident examination of the engine revealed no evidence of preimpact failure or malfunction of the powertrain, ignition, air induction, exhaust, or carburetor heat systems. Although there was fuel contamination (particulates) found in the carburetor and airframe fuel strainer, and fibrous material inside the carburetor inlet screen, the amount and location of the contamination likely existed at the time of takeoff and the pilot did not report a loss of engine power until being at a reduced power setting on the base leg of the airport traffic pattern. Reported weather conditions were conducive to the formation of carburetor icing at glide and cruise power. Although the pilot reported that he applied carburetor heat before reducing engine power while on the downwind leg of the traffic pattern, it is likely that the ice accumulated to the degree that the carburetor heat was insufficient at the partial power setting to melt the ice that had accrued, resulting in a partial loss of engine power.

On June 22, 2022, about 1348 eastern daylight time, a Cessna 172M, N9556H, was substantially damaged when it was involved in an accident near Lancaster, Ohio. The private pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he performed a preflight inspection of the airplane and confirmed that the fuel tanks were full and absent of contamination, but he did not check the airframe fuel strainer. He reported no discrepancies during the engine run-up before takeoff. After takeoff, he turned onto the crosswind and then onto the downwind legs of the airport traffic pattern, flying on the downwind leg between 1,600 and 1,700 ft mean sea level (msl). While flying between 1,600 and 1,650 ft msl, he applied carburetor heat and then adjusted the engine rpm to 2,000. Abeam the approach end of runway 28, he reduced engine power to 1,700 rpm, extended the flaps to 10°, and heard radio calls from several other aircraft announcing they were transitioning the area. After turning onto the base leg of the airport traffic pattern, he noticed that his sight picture was “not right” and he could see the propeller blades rotating. He turned onto the final approach leg of the airport traffic pattern and, with the engine not developing power, he determined that the airplane would not reach the runway. He declared an emergency on the common traffic advisory frequency and noted a soybean field was located under the approach path. The airplane subsequently impacted about 2 ft below the top of a ditch and came to rest inverted. Examination of the airframe and engine was performed by a Federal Aviation Administration airworthiness inspector following recovery. Structural damage to the fuselage, left wing, and aft empennage was noted. Examination of the engine revealed crankshaft, camshaft, and valvetrain continuity. No evidence of preimpact failure or malfunction was noted of the air induction, ignition, or exhaust systems. No fuel contamination was noted in the right fuel tank, but because of the resting position of the airplane, no fuel was remaining in the left fuel tank. Both fuel tank caps were vented, and there was no issue with the airframe fuel vent system. The standpipe of the airframe fuel strainer was noted to have some of the black coating separated, exposing the base material, which was corroded. Black particles were noted in the fuel drained from the airframe fuel strainer and also the carburetor bowl. Additionally, the carburetor fuel inlet screen was blocked on the end opposite of the inlet by “fibrous material.” Examination of each wing fuel tank strainer revealed very slight amount of “fibrous material.” The carburetor heat control operated satisfactorily. Damage to the propeller precluded operational testing of the engine. Review of the maintenance records revealed the airplane’s last 100-hour inspection was performed on May 26, 2022. The airplane had accruedabout 44 hours at the time of the accident since the inspection. An aviation weather surface observation report taken at the accident airport about 5 minutes after the accident reported the temperature and dew point to be 93°F and 73° F, respectively. According to FAA Special Airworthiness Information Bulletin (SAIB) CE-09-35 – Carburetor Icing Prevention, those environmental conditions were favorable for icing at glide and cruise power settings.