Primary finding
Probable cause
The failure of the carburetor fuel line, which resulted in fuel starvation.
Investigator assessment
Analysis narrative
The pilot reported that about halfway through the flight the engine started to lose power. Unable to regain sufficient power, the pilot made an emergency landing in a field; the airplane collided with a stump and sustained substantial damage to the fuselage. Postaccident examination of the engine revealed fuel staining on the inside of the engine cowling due to the carburetor fuel line leaking from the braided outer casing. Examination of the fuel line revealed that it was brittle and cracked on the inside, which prevented fuel from being supplied to the carburetor.Not in docket. After the fuel line was removed and replaced with a serviceable line, the engine was started and ran continuously with no anomalies noted. No entries were found in the maintenance logbooks that showing replacement of the fuel line. The last inspection entry in the engine logbook was an annual inspection dated 6 months before the accident, that noted an inspection of the fuel system. An external visual check of the fuel line alone would not have alerted the mechanic to its condition.
Source record
Factual narrative
On October 3, 2023, about 1800 eastern daylight time, a Champion 7FC, N4878E, was substantially damaged when it was involved in an accident near Hawkinsville, Georgia. The commercial pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that he was en route to Eastman, Georgia, and about halfway through the flight he noticed a partial loss of engine power. He checked the instruments and attempted to regain full power, but was unsuccessful. He decided to make an emergency landing in a field but during the landing roll the airplane collided with a stump and nosed over, resulting in substantial damage to the fuselage and wings. During the postaccident examination of the airplane, it was determined the engine could undergo a test run. During the preparation for the test run, fuel staining was discovered inside the engine cowling. An attempt to start the engine revealed a leaking fuel line to the carburetor, which was found to be brittle and leaking from the braided outer casing. After replacing the faulty fuel line, the engine started and ran continuously without any issues.This information is not included in the docket. The maintenance logbooks were reviewed to find the service history on the fuel line. No entries were discovered that showed the replacement of the fuel line. The last inspection entry in the airframe logbook was an annual inspection dated April 4, 2023, that noted an inspection of the wing fuel tanks and plumbing. The fuel line did not fall under the Life Limited Part designation of 14 CFR Part 43.10, as any part for which a mandatory replacement limit is specified in the type design.