Accident Overview
On September 5, 2020, at approximately 1850 eastern daylight time, an American Aviation AA1, registration N6107L, was substantially damaged during a forced landing at Newnan Coweta County Airport (CCO) in Newnan, Georgia. The flight instructor and the pilot receiving instruction were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as an instructional flight.
Preflight and Flight Details
According to the flight instructor, he used the aircraft's sight gauges to estimate approximately 10 to 11 gallons of fuel on board before the flight. During preflight inspection, fuel samples were taken with no indications of contamination or water. This was the instructor's third flight with the private pilot receiving instruction, who was also a potential buyer of the airplane. The flight involved various maneuvers and simulated loss of engine power procedures, including about 8 or 9 takeoffs and landings, totaling approximately 50 minutes of flight time.
Accident Sequence
Just before the accident, the pilot and instructor were practicing a simulated loss of engine power from an altitude of about 800 feet while on the downwind leg of the traffic pattern for runway 32. After reducing engine power to idle for the simulation, the airplane descended to about 300 feet above ground level. The pilot then applied full power to go around, but the engine did not respond and remained at low power. The flight instructor took control and attempted to troubleshoot but was unable to restore engine power. As the airplane continued to descend, the instructor attempted a forced landing in the grass adjacent to runway 32. The airplane touched down on the right side of the runway, impacted a lighted taxiway sign box, veered sharply left, and subsequently impacted trees bordering the west side of the airport property.
Wreckage and Damage
The fuselage came to rest on an embankment between two trees that were impacted by the left and right wings. The impact nearly separated the left wing from the fuselage, and the right outboard portion of the wing was crushed. The airplane rested on the embankment at a steep nose-down angle of about 60°. The cockpit, fuselage, engine compartment, and propeller remained relatively intact. The quantity of fuel in the fuel tanks could not be determined due to the wreckage position, but after recovery, both fuel tanks were found empty. The condition of the fuel tanks was not documented, and whether any fuel spillage occurred at the site before recovery was not determined.
Engine Examination
The airplane was equipped with a Lycoming O-235-L2C engine driving a two-blade Sensenich fixed-pitch propeller. Examination of the engine confirmed powertrain continuity through 720° of crankshaft rotation at the propeller hub. An engine run was then conducted using a portable fuel tank supplying fuel through the right fuel tank supply line; the fuel selector was left in the same position as found at the accident site. After priming, the engine started on the second attempt and ran continuously at idle speed, with all indications remaining nominal. Engine power was applied from idle to maximum with no anomalous behavior from any systems. Examination of the wreckage and engine revealed no preimpact mechanical anomalies that would have precluded normal engine operation.
Fuel System and Consumption
The airplane had a total fuel capacity of 24 gallons (12 gallons in each wing tank cell), with 22 gallons usable. Fuel was managed by a selector valve marked left, right, and off, and quantity was indicated by sight gauges. The Lycoming engine operator's manual stated that at performance cruise (75% rated power, 2,500 rpm), fuel consumption was 6.7 gallons per hour (gph); at full power (2,800 rpm), it was 9.5 gph. The airplane's pilot operating handbook noted that performance information was derived from flight tests and corrected to standard conditions, with actual performance varying based on atmosphere, engine and propeller condition, mixture leaning, and other variables. At 2,500 feet and 85% rated power (2,600 rpm), consumption was 7.3 gph; at 77% rated power (2,500 rpm), it was 6.5 gph. During a postaccident interview, the flight instructor stated that the engine consumed about 6 gph.