Aviation Accident Summaries

Aviation Accident Summary ERA21LA321

Springfield, TN, USA

Aircraft #1

N825ME

CUBCRAFTERS INC CC11-160

Analysis

The pilot stated that the engine suddenly stopped producing power while climbing at an altitude of about 400 ft above ground level after a touch-and-go landing. With no time to troubleshoot the reason for the loss of power, the pilot performed a forced landing to a field, where the airplane contacted a fence and the fuselage and right wing were substantially damaged. Weather conditions in the area at the time of the accident flight were conducive to serious carburetor icing at glide power; however, the description of the partial loss of engine power and the phase of flight at which it occurred were not consistent with carburetor icing. A postaccident examination and test run revealed that the engine was able to operate normally. During the examination it was noted that a fuel valve was leaking, though it is likely that this was due to damage sustained during the accident. Additionally, the electronic ignition system backup battery voltage was low. During the engine test run when the main ignition system circuit breakers were deactivated, and with the right side backup ignition selected, the engine lost power (and appropriate annunciations were illuminated on the instrument panel). Given that the pilot did not report any ignition system issues or annunciations, it is unlikely that the voltage issue noted with the backup system played a role in the reported loss of engine power. Based on this information, a reason for the loss of engine power could not be determined.

Factual Information

On August 6, 2021, about 1620 central daylight time, an experimental Cubcrafters Inc., CC11-160, N825ME, was substantially damaged when it was involved in an accident near Springfield, Tennessee. The airline transport pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that after refueling with 18 gallons of aviation fuel, the pilot and a passenger took off from Springfield Robertson County Airport (M91) Springfield, Tennessee, and flew to a private airport about 7 nautical miles east. The airplane was performing well and there were no anomalies observed during the flight. After landing and coming to a full stop at the airport, they conducted another takeoff, flew a normal traffic pattern, and conducted a touch-and-go landing. During the subsequent climb, when about 400 ft above ground level, the engine suddenly stopped producing power. The pilot further described that, “there was no sputter or indication, it just stopped.” There was little time to troubleshoot as the airplane was descending quickly and the pilot performed a forced landing in a field. Upon landing, the airplane struck a fence and the landing gear collapsed before the airplane came to rest to rest. 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 aviation fuel that was clean and free of debris. There was oil in the engine reservoir and no debris or metallic material in the oil filter. The electronic ignition system produced spark on all spark plug electrodes. A download of the Garmin G3X Electronic Flight Instrument System was conducted. The download revealed that at an altitude of about 1,000 ft mean sea level, while climbing about 1,000 ft per minute at a groundspeed of 80 kts, the engine rpm, oil pressure, and exhaust gas temperatures suddenly decreased, followed rapidly by a decrease in fuel flow. There were no associated crew-alerting system alerts recorded during the flight and a review of the most recent maintenance records did not reveal any past irregularity or other anomalous behavior from the engine or other systems. A 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. During the engine run, the circuit breakers from the main power supply were disengaged and the right ignition switch was turned off, which resulted in a loss of engine power due to low voltage on the back up battery. A leaking fuel valve was discovered in the fuel system during the examination. At 1532, the weather reported at Outlaw Field Airport (CKV), Clarksville, Tennessee, which was located about 24 nautical miles west of the accident site, included a temperature of 29°C and a dew point 17°C. The calculated relative humidity at this temperature and dewpoint was 48 percent. Review of the icing probability chart contained within Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35 revealed the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power."

Probable Cause and Findings

A loss of engine power for undetermined reasons.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports