The Spruce Goose was the world’s largest plane (until recently), built for a war that was already over and never found a place in our modern world. What was the aircraft like, and why did it only fly once?
What was the Spruce Goose?
At the time, the Spruce Goose plane had the biggest wingspan in the world, at 320 ft 11 in (97.82 m). It was a flying boat that had eight engines and would be able to carry more cargo than anything else ever conceived.
It had the following specifications:
- A cruise speed of 250 mph (400 km/h, 220 knots )
- A range of 3,000 mi (4,800 km, 2,600 nmi)
- Passenger capacity of 750 and three crew
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Why was it built?
In 1942, the US Navy was losing ships to German U-boats in the Atlantic and needed a way to transport troops and supplies to Europe by air. Shipbuilder Henry J. Kaiser came up with the idea to work with the famous plane designer Howard Hughes to create the largest aircraft ever built.
The dubbed HK-1 would be able to carry up to 150,000 pounds (68,000 kg) of materials, 750 troops, or two 30-ton M4 tanks. Different concepts were considered, including a double fuselage with up to eight engines. The plane would need to be built from wood and fabric (rather than aluminum), as wartime rationing prevented the use of precious metals. Mind you, this wasn’t any normal wood but a particular composite of plywood and resin made from Birchwood.
Alas, the aircraft would take so long to design and build (thanks to Howard Hughes’ perfectionism) that Kaiser would abandon the project. Hughes would continue the project in his absence and rename it the H-4 Hercules. The military downscaled the project at the end of the war and reduced the program to a single prototype.
Why did it only fly once?
Construction finished at the cost of $23 million ($283 million today) in 1947 (World War Two ended in 1945). On November 2nd, 1947, the plane underwent water taxi tests and, on the final test, took off for a brief 26 seconds for a mile (1.6 km) at an altitude of 70 feet (21 meters).
Alas, without government support or use, the plane would then sit in a hangar with its full capacity unused. Despite being fully built, it had no purpose, and further testing was unneeded.
“The Hercules was a monumental undertaking. It is the largest aircraft ever built. It is over five stories tall with a wingspan longer than a football field. That’s more than a city block. Now, I put the sweat of my life into this thing. I have my reputation all rolled up in it, and I have stated several times that if it’s a failure, I’ll probably leave this country and never come back. And I mean it.” – Howard Hughes speaking to the Senate War Investigating Committee in 1947
The aircraft would hold the wingspan record until the recent history when the double-747 fuselage Stratolauncher took to the skies – channeling the inner spirit of the Spruce Goose.
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