Accident Details
On April 28, 2013, at about 1234 eastern daylight time, an Aeronca 11AC, registration N3503E, came to rest in a nose-down attitude on a golf course near Hoosick Falls, New York. The commercial pilot, who was the sole occupant, sustained serious injuries. The airplane sustained substantial damage to both wings, the firewall, and the fuselage. The flight was conducted under 14 CFR Part 91 as a personal flight, and no flight plan had been filed. Visual meteorological conditions prevailed. The local flight originated from Chapin Field Airport (1B8) in Cambridge, New York.
Eyewitness Accounts
Several witnesses reported observing the airplane flying overhead. Some heard the engine "throttle down" before the aircraft appeared to enter a flat turn. One witness described the airplane as "flying sideways," while another characterized its motion as a "large circular motion but kept losing altitude." Multiple witnesses noted that the engine was operating at an "idle" position throughout the event.
Pilot Statement
Attempts to interview the pilot were unsuccessful; however, his spouse relayed to the NTSB that the pilot stated the airplane "all of sudden would not respond to commands."
Aircraft Information and Maintenance
The airplane was registered to a private individual. According to maintenance records, the most recent annual inspection was completed on September 12, 2012, at a tachometer reading of 1011.79 hours and a total time in service of 1684.33 hours. The mechanic reported inspecting all control cables, pulleys, attach fittings, hinges, and points. At the time of the accident, the aircraft had 1702.33 total hours, indicating approximately 18 hours of operation since the inspection. No entries in the records indicated that the wing attach brackets had ever been replaced or welded. A search of the NTSB database revealed no previous reported accidents for this airplane.
Examination of Wing Attach Brackets
Post-accident examination by an FAA inspector found the right wing with impact crush damage on the outboard half, and the left wing separated from the fuselage at the aft wing attachment bracket. The right and left wing aft attachment brackets were sent to the NTSB Materials Laboratory for analysis. Each bracket consisted of two plates held together by two cross members welded between them. On the right bracket, one cross member was missing and not recovered, while the other remained attached to only one plate. Fracture surfaces on both cross members were consistent with overstress. The left wing bracket comprised a welded cluster of tubing, with one tube bent out of position and a corresponding fracture at the junction where it joined other tubes. The cross members had separated from the plates, leaving one attached per plate. Deformation and fracture surfaces again indicated overstress. Further examination of the welds connecting the cross members to the plates revealed that they appeared to lack full penetration into the base material.