What’s inside the Stratolaunch? the worlds biggest aircraft going to start its service in 2020. Stratolaunch is the world biggest aircraft. The world's largest plane is so big, it needs two fuselages with separate cockpits. Allen's goal for the company and its namesake aircraft was to "provide convenient, reliable, and routine access to low-Earth orbit." Its 385-foot wingspan makes it wider than a football field, and the larges airplane by wingspan. The aircraft is 238 feet long, 50 feet tall, and has six high-bypass-ratio turbofan engines. It weighs 500,000 pounds and needs 28 wheels between its two fuselages.