CEN23LA083

The pilot reported a gradual loss of engine power during cruise flight. He applied carburetor heat when the engine began running rough, which seemed to make the situation worse. Eventually, the available engine power was insufficient to maintain altitude and it became clear the airplane would not be able to reach the destination airport. The pilot executed a forced landing to a field; however, he flared too high and landed hard. The airframe sustained substantial damage to both wings and the fuselage. A postaccident engine examination revealed minor anomalies with respect to the carburetor heat system, and those anomalies may have slightly reduced the effectiveness of the carburetor heat when applied. The remaining anomalies identified during the engine examination were not consistent with a gradual loss of engine power and did not contribute to the accident. Meteorological conditions were conducive to the formation of carburetor icing during cruise flight. Based on the available information, it is likely that the formation of carburetor icing, which the carburetor heat system was unable to adequately remove, resulted in the loss of engine power. In addition, the hard landing that occurred during the forced landing may have increased the extent of damage to the airframe.

On January 15, 2023, about 0930 central standard time, a Hatz Classic airplane, N1957P, was substantially damaged when it was involved in an accident near Brashear, Texas. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported a gradual loss of engine power during cruise flight. He applied carburetor heat when the engine began running rough, which seemed to make the situation worse. Eventually, the available engine power was insufficient to maintain altitude and it became clear the airplane would not be able to reach the destination airport. He executed a forced landing to a field; however, he flared “too high” and landed hard. The airframe sustained damage to both wings and the fuselage. A postaccident engine examination noted the carburetor heat ducting appeared “insufficient for proper airflow” and the carburetor heat control arm was not fully engaged. The mechanic estimated the carburetor heat installation was about 90% functional. In addition, the electric conductivity between the magneto P-lead and the cockpit ignition switch was intermittent, and 2 ignition leads exhibited minor damage. Otherwise, the engine examination was unremarkable. Meteorological conditions were conducive to the formation of carburetor icing during cruise flight. In his statement, the pilot noted the possibility of carburetor icing as the reason for the loss of engine power.