Accident Overview
On May 29, 2022, at approximately 2055 eastern daylight time, an Aeronca 7AC, registration N1294E, was substantially damaged in an accident near Melrose, Tennessee. The pilot and passenger received minor injuries. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Flight Narrative
According to the pilot, he added about 11 gallons of fuel before departure, bringing the total to approximately 12 gallons. He departed from his private grass airstrip on his farm near Maryville, Tennessee, around 1630, and proceeded northeast. After circling his farm for about 10 minutes, he flew toward a nearby mountain range and climbed to 2,500 ft msl. He remained in the vicinity for about 15 minutes, then descended to 1,500 ft msl and turned northeast toward Seymour Air Park (TN20) in Seymour, Tennessee. The engine then lost power. The pilot turned northwest toward river bottoms about 1 mile away for a forced landing. When it became clear the airplane could not reach that area, he maneuvered toward a spot without large trees. During the forced landing, the right wing struck a tree, and the airplane spun 180 degrees before coming to rest. The pilot and passenger egressed through the cabin door. The pilot did not indicate in his written statement whether he attempted to restart the engine or applied carburetor heat after the power loss.
Wreckage Examination
Examination of the wreckage the day after the accident revealed no fuel smell or fuel leak. The fuel cap and fuel port showed extensive rust. A wooden stick indicated about an inch of fuel remained in the tank. No fuel sample was taken due to inaccessibility of the gascolator. The fuel selector on the engine panel was in the ON (down) position, the magneto switch was in BOTH, and the carburetor heat was off. The tachometer read 0047.2 hours. The right engine cowling revealed a bird’s nest on the aft cylinder. The bottom portion of the rudder was bent to the right, and the outboard portion of the right wing forward and aft spars were substantially damaged.
Engine Examination
Postaccident engine examination showed the carburetor was broken at the neck and separated from the engine, attached to the airframe only by the carburetor heat cable and fuel line from the gascolator. The intake box and fuel line were disconnected from the carburetor, with no fuel in the line. Disassembly revealed the choke plate moved freely, the throttle cable was broken at the throttle arm, a small amount of fuel in the float bowl, the float moved freely, and the fuel screen was clean. The carburetor heat cable moved freely after disconnection. The top spark plugs were clean, thumb compression was present on all cylinders, and spark was observed when turning the crankshaft. Valve rocker box covers were removed; all valves moved freely.
Fuel System Examination
The fuel system examination revealed a non-standard fuel shutoff valve installed between the fuel tank bottom and the line to the gascolator. This valve was not labeled with ON/OFF positions, could rotate 360 degrees easily, and had no detents. The fuel shutoff valve handle on the engine control panel was disconnected. The existing line from the fuel selector valve to the gascolator was properly connected with no cracks, but the gascolator bowl was missing. After disconnecting the line from the shutoff valve, fuel trickled out and stopped as the valve was rotated. No entries in the aircraft logbooks accounted for this modification. According to the Pilot Operating Handbook, the fuel tank held 13 gallons and was gravity-fed. The engine fuel consumption rate was about 4.25 gallons per hour.
Maintenance Records
The aircraft logbook showed the airplane was grounded on October 9, 1977, due to cracked cylinders, with the next entry on April 10, 2002, when it was restored and returned to service. Annual inspections occurred on several dates from 2003 to 2021. The engine logbook began April 6, 2002, documenting an overhaul (original logbook lost). Engine total time was unknown; time since overhaul was 0 hours. The last engine inspection was on November 2, 2021, with 45.5 hours since overhaul. No maintenance actions were recorded between annual inspections.
Weather
A weather reporting station about 8 miles from the accident site reported a temperature of 84°F and a dew point of 61°F. FAA Special Airworthiness Information Bulletin CE-09-35 noted that these conditions were conducive to serious carburetor icing at glide power.