Accident Overview
On April 7, 2022, at about 1002 eastern daylight time, an American AA-1 (N623W) was substantially damaged when it was involved in an accident near Kennesaw, Georgia. The pilot, the sole occupant, sustained minor injuries. The flight was operated as a personal flight under Title 14 CFR Part 91.
Flight Details
The pilot reported that the purpose was a 10-minute return flight to its base. After preflight and engine start, he obtained weather and requested taxi clearance. He performed engine run-up and instrument checks during taxi to runway 27 and requested an intersection departure. During takeoff, all engine instruments were normal. At about 500 ft agl, the engine momentarily dropped to about 800 rpm, then abruptly returned to full power. The pilot turned back toward the airport and notified the tower. The engine then reduced to idle before quitting entirely. He attempted troubleshooting using the fuel pump, switching fuel tanks, and checking the mixture, but the engine did not restart. Determining the airplane would not reach the runway, he selected a nearby road for forced landing. During approach, the airplane impacted a wire and came to rest in a grass median.
Weather Conditions
At 0950, the weather at Cobb County International Airport (RYY) included a temperature of 14°C and dew point 7°C, yielding a relative humidity of 63%. According to FAA Special Airworthiness Information Bulletin CE-09-35, these conditions were "conducive to serious icing at cruise power." The pilot did not report details about carburetor heat use during the engine run-up or before takeoff. FAA Advisory Circular 20-113 recommends applying carburetor heat when relative humidity exceeds 50% to prevent induction system icing.
Post-Accident Examination
An FAA inspector examined the accident site and found substantial damage to both wings, right elevator and horizontal stabilizer, and the rear fuselage forward of the horizontal stabilizer. A subsequent examination at a salvage facility by an NTSB investigator revealed no pre-impact mechanical anomalies. The engine oil dipstick indicated 4 quarts of dark oil; no leaks were evident. The engine case was uncompromised. Top spark plugs were normal in wear and color. Internal continuity, compression, and suction were confirmed on all four cylinders. The left magneto produced a spark on all leads; the right magneto produced a spark on 3 of 4 leads. All fuel lines forward of the firewall were secure. The electric and mechanical fuel pumps operated normally. The carburetor was clean and dry, with intact floats and unobstructed inlet screen. The propeller showed bending consistent with impact: one blade bent aft about 10° with S-bending and leading-edge damage; the other bent aft about 70°.