https://www.vice.com/en_us/article/g5gb9q/stratolaunch-roc-plane-longest-wingspan-test

The world's largest aircraft took off from Mojave Air and Space Port on Thursday morning.

This big boy was built for aerospace company Stratolaunch Systems by Scaled Composites, which develops experimental aircraft. Named the "Roc" after the giant mythological bird that could carry elephants in its talons, it has six engines and a wingspan of 385 feet—slightly longer than a football field. It's so wide, the company had to construct a custom hanger for it to fit into.