Accident Overview
On June 20, 2017, about 2000 central daylight time, an Aeronca 7BCM airplane, registration N2558E, sustained substantial damage when it impacted a bean field after a loss of control during initial climb from the Mahnomen County Airport (3N8) in Mahnomen, Minnesota. The sport pilot, who was the sole occupant, was seriously injured. The airplane was owned and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and the flight was not on a flight plan. The airplane was departing for a local flight.
Pilot Account
The pilot reported that he had flown the airplane earlier in the day. Around 1900, he returned to the airport intending to take a short local flight. He performed a preflight inspection, including fuel samples, and taxied to the run-up area where he completed before-takeoff checklist items. He departed from runway 35, and the initial takeoff roll was normal. The pilot then noticed that the airplane was not gaining airspeed and the engine was not developing full power, but he decided to continue the takeoff. Once committed, he perceived an even greater loss of power. He stated that the airplane did not exceed 150 ft of altitude. He initiated a slight bank (about 20 degrees) to avoid a highway and powerlines, after which the airplane stalled and impacted a bean field adjacent to the airport. The pilot also provided two recommendations in the NTSB accident report: aborting the takeoff at the first sign of performance issues while sufficient runway remains, and keeping noise-canceling headsets off during takeoffs and landings to better hear engine sounds.
Witness Observations
Witnesses reported that the airplane appeared to be moving slowly and not climbing before it banked to the right and impacted the ground in a nose-down attitude.
Examination Findings
A Federal Aviation Administration inspector examined the airplane. The valve covers were removed, revealing rusty valve springs. The engine could be rotated, with continuity in the crankshaft and drive train. The magnetos turned and sparked. Fuel was found in the carburetor bowl. Spark plugs showed normal color and wear. The header fuel tank was ruptured, and an auxiliary fuel tank was present in the left wing. The propeller exhibited minimal damage. Flight control continuity was confirmed. No preexisting anomalies to the engine or airframe were noted.
Weather Conditions
At 2015, the surface weather observation at 3N8 reported wind light and variable; visibility 10 miles; sky clear; temperature 20°C; dew point 8°C; altimeter 29.94 inches of mercury. According to the carburetor icing chart, conditions at the time were conducive to moderate icing at cruise power or serious icing at descent power.