Amateur-built THATCHER CX4 accident near Baker, Florida, July 16, 2022

The NTSB's narrative final · quoted from the NTSB record

The pilot reported that he had just completed an overhaul of the automotive conversion engine that was installed in the experimental amateur-built airplane. Before the day of the accident, the pilot conducted several engine ground runs. During most of the ground runs, the engine would not run smoothly when at the idle throttle setting; however, on the last ground run, the engine ran smoothly at idle. On the day of the accident, the pilot planned to break in the engine during a flight over the airport. After takeoff, while the airplane was climbing to traffic pattern altitude, the pilot felt something dripping onto his leg and decided to perform a precautionary landing. When he pulled the throttle back to idle to initiate a descent, the engine stopped producing power. Unable to restore power to the engine, he elected to execute a forced landing, during which the left wing impacted a tree. Although the pilot did not run the engine after the accident, his postaccident examination of the engine revealed no anomaly that would have precluded normal operation. The atmospheric conditions at the time of the accident were conducive to carburetor icing at glide power; however, the airplane’s engine was at a climb power setting before the pilot reduced the throttle to idle to initiate the descent. Therefore, it is not likely that the loss of engine power was the result of carburetor ice. Since the pilot had just completed an overhaul of the engine and the engine would not run smoothly at idle during several engine ground runs, it is likely that the engine idle setting was misadjusted, which resulted in the engine losing power when the throttle was reduced to idle.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.