The world’s biggest ever flying boat is so massive that its wingspan is longer than some football pitches, but it only flew once. The Hughes H-4 Hercules (best known by its nickname, the Spruce Goose) is an iconic prototype airlift flying boat that attracted headlines around the world due to its colossal size.

Built by the Hughes Aircraft Company, a firm founded by mercurial billionaire and aviator Howard Hughes, it was planned to be used as a transatlantic transport able to move 750 troops across the Atlantic during World War 2. It was also billed as capable of carrying a cargo of immense weight, such as two Sherman Tanks, though this was never proved through testing.

The body of the epic aircraft was made mostly of laminated birch and had an empty weight of nearly 113,400kg, with a fuselage stretching over 218ft.

It was powered by eight engines, each with four-bladed propellers measuring 17 feet in diameter.

Four hung on either side of the fuselage across the plane’s staggering 320ft wingspan, longer than some football pitches, which generally range between 300 and 390 feet.

The project wasn’t completed in time for the vast flying machine to be used by the American air force, and the prototype was flown only once by Hughes himself.

The test flight was carried out on November 2, 1947, two years after the war ended. It took off from Long Beach Harbour, California, with the plane airborne for 26 seconds and flying a mile or so before touching back down on the water.

Footage of the event shows the plane flying around 70 feet above the water. Ultimately, it never moved beyond the prototype stage and became a something of a historical curiosity.

The plane is currently housed at Evergreen Aviation & Space Museum in McMinnville in Oregon, where aviation enthusiasts can get a sense of its scale up close.

For decades, the Spruce Goose was not just the biggest flying boat, but also the aircraft with the biggest wingspan.

This record was only beaten in 2019 with the maiden flight of the twin-fuselage Stratolaunch jet, which has a wingspan of around 385ft.