Accident Overview
On November 4, 2022, at approximately 1715 central standard time, an American Aviation AA-1A, registration N7254L, sustained substantial damage during an accident near Sparta, Tennessee. The private pilot, who was the sole occupant, was uninjured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a post-maintenance test flight.
Flight Details
The pilot reported that during an annual inspection the previous day, he discovered and repaired an irregularity with an air intake hose. The accident flight was intended to test the repair. Before takeoff, the pilot performed a thorough preflight inspection and engine run-up, observing no anomalies.
Shortly after departure, the pilot climbed the airplane to approximately 6,800 ft mean sea level (msl) while flying rectangular patterns directly over the airport. He then initiated a descent to 4,500 ft msl. During the descent, without any warning, the engine completely lost all power. The pilot stated he never reduced power during the descent; he maintained takeoff or cruise power for the entire flight.
Attempts to restart the engine were unsuccessful. As the airplane continued descending, the pilot approached the airport on the downwind leg of the traffic pattern, abeam the runway 22 numbers at 4,000 ft msl (2,075 ft above ground level). Judging the airplane too high to land on the runway, he executed a slip to lose altitude. Upon completing the slip, the pilot realized he had over-corrected and was too low to reach the runway. He elected to perform a forced landing in a field about half a mile before the runway. The pilot flew below powerlines and touched down hard on rough, hilly terrain, impacting a fence and brush before the airplane came to rest.
Engine Examination
A Federal Aviation Administration (FAA) inspector examined the wreckage. The left and right wings were crushed at multiple locations, and the fuselage was buckled under the engine compartment. Further inspection by the FAA inspector and a mechanic revealed that the engine air inlet was packed with dirt, but the induction system components were otherwise intact and unobstructed. The carburetor heat butterfly valve was in the open (cold) position. Fuel was present in the carburetor, and the fuel pumps operated normally with no anomalous behavior. Engine crankshaft continuity was established, and the spark plugs exhibited normal coloration.
Weather Conditions
The recorded temperature and dew point near the accident site were about 71°F and 50°F, respectively. On the carburetor icing probability chart, these values fell within the "serious icing – glide-power" range. At approximately 6,000 ft msl, near where the loss of engine power occurred, weather sounding data indicated a temperature of about 49°F and a dewpoint of 35°F, which bordered the serious icing range at a cruise power setting.