CEN22LA185

During a flight of an airplane after being rebuilt, the engine began to run rough when the airplane was about 150 ft above ground level. Witnesses observed the airplane make a steep left turn in a nose high attitude back toward the direction of the runway. The left wing subsequently dropped, and the airplane entered a rapid descent until it impacted the ground in a nose-low attitude. The airplane was largely consumed by a post-crash fire. During a postaccident examination, there were no mechanical anomalies found that would have precluded normal operation. However, the extent of the post-crash fire prevented an examination of the fuel and ignition systems. When the temperature and dewpoint were plotted on a carburetor icing probability chart, the result was that the airplane was operating in conditions that were conducive to serious carburetor icing at glide power. The investigation was unable to determine if this contributed to the engine roughness. It is likely that the pilot exceeded the critical angle of attack for the airplane as he was returning to the airport to make a precautionary landing when the engine began running rough.

On April 28, 2022, about 1040 central daylight time, a Superior Culver LFA, N37888, was destroyed when it was involved in an accident near Syracuse, Kansas. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airplane had recently been rebuilt and the engine had been overhauled. The purpose of the flight was to transport the airplane from the maintenance facility to its owner in another state. Witnesses reported that after takeoff, and about 150 ft above ground level, the engine began to run rough. The pilot made a steep left turn in a nose-high attitude as if he were attempting to return to the runway. The engine continued to run rough as the left wing dropped and the airplane entered a rapid descent before impacting the ground in a nose-low attitude. The airplane was largely consumed by a post-crash fire. During a postaccident examination, flight control continuity was established to all control surfaces. The magnetos remained attached to the engine and were thermally damaged along with both ignition harnesses. The carburetor sustained impact and thermal damage. The spark plugs were removed and found to be unremarkable. No evidence of a catastrophic engine failure was present. When the temperature (66°F) and dewpoint (55°F) were plotted on a carburetor icing probability chart, the result was that the airplane was being operated in an area conducive to serious carburetor icing at glide power. (See figure 1) Figure 1: Carburetor Icing Probability Chart. Reference: Special Airworthiness Information Bulletin CE-09-35