The aircraft was intended as a forerunner of much larger craft thatwould contain helium; these designs were dubbed "Dynairships." One proposal, the AEREON 340, was to have been 340 feet (100 m) long, with a wingspan of 256 feet (78 m) and total lift of 400,000 pounds (180,000 kg). Powered by four 5,500 horsepower Rolls-Royce Tyne turboprop engines, it was claimed to be capable of carrying intermodal containers or semi-trailers, operating slightly heavier than air. A patent for "a cargo-carrying air ship comprising a gas-filled, low aspect ratio deltoid wing" was granted in 1969; according to this patent, "extremely large ships, having lengths in excess of 1,000 feet (300 m)" and capable of economically transporting "large payloads, ranging up to 1,000 long tons or more" over long distances, were feasible.