OVERVIEW
The Hughes H-4 Hercules, ridiculed as the Spruce Goose, remains the largest flying boat ever constructed and features the largest wingspan of any aircraft ever made.
The Hughes H-4 Hercules, ridiculed as the Spruce Goose, remains the largest flying boat ever constructed and features the largest wingspan of any aircraft ever made.
YEAR: 1945
STATUS: Retired, Out-of-Service
MANUFACTURER(S): Hughes Aircraft - USA
PRODUCTION: 1
OPERATORS: United States (cancelled)
SPECIFICATIONS
Unless otherwise noted the presented statistics below pertain to the Hughes H-4 Hercules model. Common measurements, and their respective conversions, are shown when possible.
Unless otherwise noted the presented statistics below pertain to the Hughes H-4 Hercules model. Common measurements, and their respective conversions, are shown when possible.
CREW: 3
LENGTH: 218.67 feet (66.65 meters)
WIDTH: 320.01 feet (97.54 meters)
HEIGHT: 79.33 feet (24.18 meters)
WEIGHT (MTOW): 396,832 pounds (180,000 kilograms)
ENGINE: 8 x Pratt & Whitney 28-cylinder R-4360 propeller engines developing 3,000 horsepower each.
SPEED (MAX): 199 miles-per-hour (320 kilometers-per-hour; 173 knots)
RANGE: 2,983 miles (4,800 kilometers; 2,592 nautical miles)
CEILING: 20,899 feet (6,370 meters; 3.96 miles)
RATE-OF-CLIMB: 1,000 feet-per-minute (305 meters-per-minute)
ARMAMENT
None.
None.
VARIANTS
Series Model Variants
• HK-1 - Original Design Designation that reflects the collaborative efforts of design and concept from Henry Kaiser and Howard Hughes ("HK").
• H-4 - Base Designation with the wihtdrawal of Henry Kaiser from the project.
• HFB-1 - Another designation attributed as a recognition of "Hughes Flying Boat - First Design".
Series Model Variants
• HK-1 - Original Design Designation that reflects the collaborative efforts of design and concept from Henry Kaiser and Howard Hughes ("HK").
• H-4 - Base Designation with the wihtdrawal of Henry Kaiser from the project.
• HFB-1 - Another designation attributed as a recognition of "Hughes Flying Boat - First Design".
HISTORY
Detailing the development and operational history of the Hughes H-4 Hercules (Spruce Goose) Heavy-Lift Transport / Flying Boat Prototype. Entry last updated on 6/28/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com.
Detailing the development and operational history of the Hughes H-4 Hercules (Spruce Goose) Heavy-Lift Transport / Flying Boat Prototype. Entry last updated on 6/28/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com.
This famous Howard Hughes flying boat aircraft - formally designated by Hughes Aircraft as the H-4 "Hercules" - only ever achieved a single flight (with Hughes himself at the controls) and was only produced in a single working example. The folly of the project garnered the H-4 the nickname of "Spruce Goose" and largely termed a failure in the scope of World War 2-era aircraft design. The primary drive behind such a large airframe was in providing the United States military - then committed to war in Europe and the Pacific - with an oversized transport capable of airlifting large quantities of battlefield equipment to the front. This was strengthened by regular losses of Allied shipping from German U-Boats in the Atlantic and elsewhere, taking their toll on vital supplies attempting trying to reach forces in Europe. As such, a military requirement was put forth for a trans-Atlantic freighter-type aircraft capable of a considerable payload.
Despite the seemingly promising nature of the H-4 design, it simply arrived too late in the war to serve much of a purpose, additionally adding to the image of the project as a complete failure for Hughes. The H-4 also suffered from the defense spending drawn down once the war had officially come to a close - many projects were either suspended indefinitely or cancelled outright. Hughes was then forced to appear before a Senate committee to answer for government funds spent on his H-4.
Upon its completion, the H-4 became the world's largest aircraft and largest flying boat ever designed and produced to that point. Power was served through 8 x Pratt & Whitney R-4360 28-cylinder engines developing 3,000 horsepower each. Four engines were fitted to a wing. Each wing was high-mounted in its installation and straight in its general design with the engine nacelles fitted at the leading edges. Each wing itself was the full wingspan of just one competing Boeing B-29 "Superfortress" four-engined heavy bomber. To demonstrate the internal carrying capacity of the H-4, the hold could service up to 700 combat infantry or two M4 Sherman Medium Tanks. Endurance of the aircraft was estimated to be approximately 21 hours of flight time. Its flying boat qualities - aided by its boat-like hull and outboard-mounted pontoon legs - allowed the H-4 to take-off and land from just about any water source. Additionally, the aircraft was constructed of wood (birch) which helped buoyancy and would not require heavy use of metals in its construction (metal proving a critical wartime resource). The wood approach was also spanned into another Hughes wartime project - the D-2 heavy fighter (detailed elsewhere on this site). The "Spruce Goose" ridicule is related to the product's heavy use of wood in its construction.
The initial H-4 concept was drawn up by Henry Kaiser while the direct design was put together by engineer Glenn Odekirk. Howard Hughes served as the project's overseer and would be the hands at the controls during her one and only flight. The one and only prototype was saved in the post-war draw down and can be seen in its full glory at the Evergreen Aviation Museum of McMinnville, Oregon, USA.
As much as aviation technology has advanced to this day (November 2013), the Hughes H-4 Hercules still maintains the largest wingspan of any aircraft ever built, let alone considered for production. This claim to fame includes even the mammoth American Boeing 747 and the Soviet/Russian An-225 Mriya offerings. Additionally, no other flying boat design has bested her dimensions.
Despite the seemingly promising nature of the H-4 design, it simply arrived too late in the war to serve much of a purpose, additionally adding to the image of the project as a complete failure for Hughes. The H-4 also suffered from the defense spending drawn down once the war had officially come to a close - many projects were either suspended indefinitely or cancelled outright. Hughes was then forced to appear before a Senate committee to answer for government funds spent on his H-4.
Upon its completion, the H-4 became the world's largest aircraft and largest flying boat ever designed and produced to that point. Power was served through 8 x Pratt & Whitney R-4360 28-cylinder engines developing 3,000 horsepower each. Four engines were fitted to a wing. Each wing was high-mounted in its installation and straight in its general design with the engine nacelles fitted at the leading edges. Each wing itself was the full wingspan of just one competing Boeing B-29 "Superfortress" four-engined heavy bomber. To demonstrate the internal carrying capacity of the H-4, the hold could service up to 700 combat infantry or two M4 Sherman Medium Tanks. Endurance of the aircraft was estimated to be approximately 21 hours of flight time. Its flying boat qualities - aided by its boat-like hull and outboard-mounted pontoon legs - allowed the H-4 to take-off and land from just about any water source. Additionally, the aircraft was constructed of wood (birch) which helped buoyancy and would not require heavy use of metals in its construction (metal proving a critical wartime resource). The wood approach was also spanned into another Hughes wartime project - the D-2 heavy fighter (detailed elsewhere on this site). The "Spruce Goose" ridicule is related to the product's heavy use of wood in its construction.
The initial H-4 concept was drawn up by Henry Kaiser while the direct design was put together by engineer Glenn Odekirk. Howard Hughes served as the project's overseer and would be the hands at the controls during her one and only flight. The one and only prototype was saved in the post-war draw down and can be seen in its full glory at the Evergreen Aviation Museum of McMinnville, Oregon, USA.
As much as aviation technology has advanced to this day (November 2013), the Hughes H-4 Hercules still maintains the largest wingspan of any aircraft ever built, let alone considered for production. This claim to fame includes even the mammoth American Boeing 747 and the Soviet/Russian An-225 Mriya offerings. Additionally, no other flying boat design has bested her dimensions.
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General Assessment (BETA)
Firepower
Performance
Survivability
Versatility
Impact
Values are derrived from a variety of categories related to the design, overall function, and historical influence of this aircraft in aviation history.
MF Power Rating (BETA)
18
The MF Power Rating takes into account over sixty individual factors related to this aircraft entry. The rating is out of 100 total possible points.
Relative Maximum Speed Rating
Hi: 200mph
Lo: 100mph
This entry's maximum listed speed (199mph).
Graph average of 150 miles-per-hour.
City-to-City Ranges
NYC
LDN
LDN
PAR
PAR
BER
BER
MSK
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TKY
TKY
SYD
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LAX
LAX
NYC
Graph showcases the Hughes H-4 Hercules's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
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Altitude Visualization
