The two pilots testing a Wright Brothers' Model B experimental aircraft were killed when the Lycoming-powered replica, one of two flying versions belonging to the Ohio-based non-profit, Wright B Flyer Inc, crashed in a field on 30 July.
Killed were Mitch Cary, a former US Air Force test pilot and programme manager at the Wright-Patterson Air Force Base, and Don Gum, an engineer working simulation and flight dynamics roles at Wright-Patt.
News outlets said the aircraft had accumulated about 25 of the required 40 hours of local area test flights, needed to prove out the vehicle's safety to the FAA. Wright B Flyer had planned to use the "Silver Bird", built for easy assembly and disassembly, for demonstrations around the world.
An earlier replica, the Brown Bird, was built in the mid-1980s and has traveled as far as Berlin for flight demonstrations.
Below is a video of the Silver Bird during test flights earlier this year.