Incident Overview
On August 6, 2021, at approximately 1620 central daylight time, an experimental Cubcrafters Inc. CC11-160, registration N825ME, sustained substantial damage during an accident near Springfield, Tennessee. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airline transport pilot and a pilot-rated passenger were not injured.
Flight Sequence
According to the pilot, after refueling with 18 gallons of aviation fuel, the airplane departed from Springfield Robertson County Airport (M91) and flew to a private airport about 7 nautical miles east. The flight was uneventful with no observed anomalies. After landing and coming to a full stop, the pilot conducted another takeoff, flew a normal traffic pattern, and performed a touch-and-go landing. During the subsequent climb, at about 400 feet above ground level, the engine suddenly stopped producing power. The pilot reported that there was no sputter or indication; it just stopped. With little time to troubleshoot due to the rapid descent, the pilot executed a forced landing in a field. Upon landing, the airplane struck a fence, causing the landing gear to collapse before coming to rest.
Postaccident Examination
A postaccident examination of the airframe and engine revealed that the fuselage was fractured and dented in several locations, and the leading edge of the right wing was damaged. The fuel tank contained clean aviation fuel free of debris. Oil was present in the engine reservoir, and the oil filter contained no debris or metallic material. The electronic ignition system produced spark on all spark plug electrodes.
A download of the Garmin G3X Electronic Flight Instrument System indicated that at an altitude of about 1,000 feet mean sea level, while climbing at approximately 1,000 feet per minute and a groundspeed of 80 knots, engine rpm, oil pressure, and exhaust gas temperatures suddenly decreased, followed rapidly by a decrease in fuel flow. No crew-alerting system alerts were recorded during the flight. A review of the most recent maintenance records revealed no past irregularities or anomalous behavior from the engine or other systems.
Engine Testing
Further examination of the engine and airframe was conducted by a mechanic under the oversight of a Federal Aviation Administration inspector. During the examination and subsequent engine test runs in various configurations, the engine operated normally with no anomalous behavior noted. However, during an engine run, when the circuit breakers from the main power supply were disengaged and the right ignition switch was turned off, a loss of engine power occurred due to low voltage on the backup battery. Additionally, a leaking fuel valve was discovered in the fuel system during the examination.
Weather Conditions
At 1532, the weather reported at Outlaw Field Airport (CKV), Clarksville, Tennessee, about 24 nautical miles west of the accident site, included a temperature of 29°C and a dew point of 17°C, with a calculated relative humidity of 48 percent. A review of the icing probability chart in FAA Special Airworthiness Information Bulletin CE-09-35 indicated that the atmospheric conditions at the time were "conducive to serious icing at glide [idle] power."