Accident Overview
During a routine flight, the airplane experienced a loss of engine power in cruise flight, leading to a forced landing and a hard touchdown on the runway.
Flight History
After a normal departure, the airplane climbed to approximately 4,800 feet mean sea level (msl). The pilot noticed an audible difference in engine operation, characterized by intermittent pauses. While returning to the airpark, the engine continued to operate abnormally and began making severe "popping" sounds. Despite the pilot's troubleshooting efforts, the engine failed to respond and subsequently lost power.
Landing
The airplane touched down about one-third of the way down the runway, contacting the surface hard.
Post-Accident Inspection
A post-accident inspection performed by a Federal Aviation Administration certificated mechanic who also holds an Inspection Authorization (IA) revealed that the mixture cable had disconnected at the carburetor. Specifically, the mixture linkage was separated where the cable adjoins the mixture control arm.
Pilot and Mechanic Observations
The pilot and mechanic opined that the separation of the linkage would decrease the fuel supply and alter the fuel/air ratio, resulting in a subsequent loss of power.
Maintenance History
The airplane had last undergone an annual inspection 44 flight hours prior to the accident. The mixture cable was inspected during that annual inspection. The pilot stated that due to the location of the mixture cable, the mechanic would have to remove the cable from the throttle arm to inspect it in its entirety.
Service Manual Requirements
The airplane's service manual states that during every 100-hour inspection, the mechanic should inspect the mixture cable for "travel and operating condition."