Hughes H-4 Hercules, familiarly known as the Spruce Goose, was the world’s largest plane. However, it was built for a war that was already over and never found a place in our modern world.
World’s largest wingspan
Next week will mark 75 years since the Spruce Goose flew for the first and last time. During this period, 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 weighed 400,000 lbs (181,436 kg). It 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).
- A range of 3,000 mi (4,800 km, 2,600 NM).
- Passenger capacity of 750 and three crew members.
Why was it built?
In 1942, the US Navy was losing ships to German U-boats in the Atlantic Ocean 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 ($306 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.
Amid amplified concerns about national expenditure, Hughes was summoned to appear before a Senate Committee in 1947.
“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.
Previously on display in Long Beach, California, between 1980 and 1992, the airframe is still in good condition. It can be seen at the Evergreen Aviation & Space Museum in Oregon.
The aircraft would hold the wingspan record until the recent history when the double-Boeing 747 fuselage Stratolaunch took to the skies – channeling the inner spirit of the Spruce Goose. Moreover, When it comes to everyday aviation, the An-225 ruled when it came to size until it was destroyed this year following the invasion of Ukraine.
With six engines, the Scaled Composites Model 351 Stratolaunch is a double fuselage unit and has the largest wingspan of any aircraft in history, measuring 117 m (384 ft). Like the Spruce Goose, the program has also been met with several challenges. More recently, a test flight was abandoned after unexpected results.
Nonetheless, From the Spruce Goose to the 747 Stratolaunch, these juggernauts will always turn heads when spotted. The H-4 Hercules may not have seen much action, but it’s an example of the pioneering nature that is embedded in the aviation industry.
What are your thoughts about the H4-Hercules? What do you make of the aircraft’s overall size? Let us know what you think of the plane and its history in the comment section.