On September 21, 2020, about 1430 central daylight time, an unregistered experimental Quicksilver airplane was substantially damaged when it was involved in an accident near Marengo, Indiana. The pilot sustained minor injuries. The flight was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that he and a friend were completing a long, multi-leg trip. As he approached the grass strip, he advanced the throttle, but the engine did not respond with increased power. He thought that the engine experienced carburetor icing since the engine acted in a very similar manner as the previous occasions that he had carburetor icing. He landed on the grass strip without incident and shut down the engine. He and his friend were on the ground for about 30 minutes and unloaded cargo from his airplane. He decided to fly the airplane back to his residence, so he started the engine without issue. After takeoff he circled above the strip several times at full power, then decreased the power and proceeded toward home. In a written statement provided by the pilot 2 days following the accident, he stated that after reaching about 500 ft and turning toward his destination, the throttle would not advance. He turned toward an emergency landing area and became “disoriented and clipped a tree.”
He wrote in the NTSB Form 6120 Aircraft Accident/Incident Report that after reducing the power, the engine went to idle and would not respond to changes in throttle position. He stated that he attempted to turn back to the runway and while descending, the left wing impacted a tree. Additionally, under the section titled Operator/Owner Safety Recommendation he wrote that he “[s]hould have waited for carburetor icing to melt.”
The pilot’s friend who witnessed the accident, stated that on the previous flight the pilot reported engine issues and was unable to achieve more than idle power. The pilot landed the airplane without incident and indicated that the engine issues might have been to due carburetor ice. The pilot added fuel to the airplane for a total of 4 to 5 gallons available. The pilot told the witness that he would depart, then remain above the strip until he confirmed that the engine was operating normally. After takeoff, the pilot flew the airplane above the strip and in the immediate area for a few minutes. He stated that after circling at 200 ft above ground level (agl), the airplane returned toward the runway an appeared to setup for landing. The engine did not sputter or hesitate, but it was not running at a high rpm, and he thought the pilot had decreased the throttle for landing. He stated that the airplane descended too low and flew toward a set of trees adjacent to the strip. The left wing impacted a tree and the airplane rotated to the left, then impacted the ground in a nose low attitude. The engine stopped abruptly upon ground impact.
The responding Federal Aviation Administration (FAA) inspector completed a postaccident examination of the airplane. He reported that the engine was not equipped with a carburetor heating system. The engine was unable to run since the propeller had been removed. There were no preimpact anomalies observed during the examination.
The Rotax installation manual states, “if the aircraft is to be operated in climatic conditions where carburetor icing is likely to occur, a heating system must be fitted.”
According to the carburetor icing probability chart in FAA Special Airworthiness Information Bulletin (SAIB) CE-09-35, weather conditions at the accident site were conducive to serious carburetor icing at glide power.