In the late 1940s, the US Navy feared that the US Air Force would control the American nuclear weapons stockpile. To address this concern of, the Navy decided to build a nuclear-armed strategic bomber of its own, the North American AJ/A-2 Savage twin-engine strategic bomber. However, the Savage was a piston-engine warplane, and gas turbine engines made it obsolete by the time it reached service in 1950. With General Curtiss Lemay, the head of Strategic Air Command (SAC), engaged in a lobbying blitz to have Congress divert funds for nuclear weapons delivery systems to US Air Force strategic bombers, the US Navy in January 1948 issued its OS-111 requirement for a jet-powered strategic bomber to operate from the planned USS United States aircraft carrier that could carry either a 10,000 lb (4,500 kg) bomb load or a nuclear weapon. Because the United States would allow the Navy to conduct nuclear strikes on large parts of the globe that the USAF could not reach with its existing bomber fleet, it was crucial to prevent the US Navy from being finished as a major service in case the Air Force got a hold on all US nuclear weaponry. A total of seven companies from submitted bids for the OS-111 requirement: Convair, Curtiss-Wright, Douglas, Fairchild, Lockheed, North American, and Republic (Zichek 2009 is consulted for details of these submissions). Of these proposals, the Convair proposal had three Westinghouse J40 turbojets (two under the wings and third buried in the rear fuselage), while the Douglas (El Segundo) D-593 had two underwing Westinghouse J40 turbojets and the Douglas (Santa Monica) Model 1181 was powered by three J40 tubojets (two in the wing roots and a third in the rear fuselage), whereas the Lockheed L-187 encompassed various designs ranging from swept-wing jet- and turboprop-powered aircraft to a jet-powered flying wing, and North American's RD-4554 was studied in conventional and flying wing layouts (Butler 2010, 2021). (A number of alternate layouts for the Convair design and the Model 1181 were worked out without the third turbojet in the rear fuselage, and one alternate Convair design for the OS-111 had two J40s buried in the wing roots.) The Curtiss-Wright P-558 and Douglas D-593 were picked for further study in late 1948, and by the spring of 1949 a few modifications were made to the D-593 and P-558 designs, and the D-593 was considered the most favorable design by the Navy.
On April 23, 1949, the USS United States was cancelled by US Defense Secretary Louis Johnson due to budget cuts. Although the Navy top brass was disappointed at the cancellation of the United States-class carriers, the US Navy continued with the OS-111 competition, issued a new weight requirement to make a winning design able to operate from the Midway-class carriers. Douglas came out with a lighter version of the D-593 design, the D-593-8, and by July the Navy declared the D-593-8 the winner of the OS-111 competition. The Douglas design, officially named Skywarrior by the Navy, was designated XA3D-1 and a contract for two prototypes (BuNos 125412/125413) was signed. The first flight of the Skywarrior took place on October 28, 1952, and the aircraft was cleared for service on March 31, 1956. In the meantime, the Westinghouse J40 engines used on the A3D prototypes were to prove unreliable, and Douglas selected the more powerful Pratt & Whitney J57 turbojet to power all service test and production A3Ds. A total of 282 Skywarriors were built, and production of the A3D continued until 1961. As a strategic bomber, the Skywarrior could carry 12,800 lb (5,800 kg) of free-fall conventional bombs and mines, including one free-fall nuclear weapon. Navy crews dubbed the Skywarrior the "Whale" because of its size and less-than-slender appearance. On September 18, 1962, the A3D was redesignated A-3 under the new Tri-Service aircraft designation system. By the end of the 1950s, the strategic bomber role of the Skywarrior was rendered obsolete due to the introduction of the Polaris submarine-launched ballistic missile and the ballistic missile submarines designed to carry them. However, many A-3s would be modified to serve tactical reconnaissance, electronic warfare, and tanker roles. The Skywarrior also happened to form the basis of the Douglas B-66/RB-66 Destroyer medium bomber for the US Air Force, which first flew in June 1954 and of which 294 were built. Like the Skywarrior, the B-66 served as both a bomber, reconnaissance platform, and EW platform during its operational career, but it differed in having ejection seats.
Although the A-3 Skywarrior's career as a nuclear-armed strategic bomber was rather brief given the introduction of SLBMs, it represented a quantum leap forward in the US Navy's efforts to acquire a long-range airborne nuclear weapons delivery system for use from large carriers. Even in situations where the Americans did not use a carrier-based plane to drop a nuclear weapon in anger, the A-3's airframe gave it operational flexibility to be used for electronic warfare, reconnaissance, and tanker missions during the Vietnam War and Operation Desert Storm.
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| Douglas A3D Skywarrior (BuNo 135422) at Naval Air Station Jacksonville, Florida, mid-1950s |
On April 23, 1949, the USS United States was cancelled by US Defense Secretary Louis Johnson due to budget cuts. Although the Navy top brass was disappointed at the cancellation of the United States-class carriers, the US Navy continued with the OS-111 competition, issued a new weight requirement to make a winning design able to operate from the Midway-class carriers. Douglas came out with a lighter version of the D-593 design, the D-593-8, and by July the Navy declared the D-593-8 the winner of the OS-111 competition. The Douglas design, officially named Skywarrior by the Navy, was designated XA3D-1 and a contract for two prototypes (BuNos 125412/125413) was signed. The first flight of the Skywarrior took place on October 28, 1952, and the aircraft was cleared for service on March 31, 1956. In the meantime, the Westinghouse J40 engines used on the A3D prototypes were to prove unreliable, and Douglas selected the more powerful Pratt & Whitney J57 turbojet to power all service test and production A3Ds. A total of 282 Skywarriors were built, and production of the A3D continued until 1961. As a strategic bomber, the Skywarrior could carry 12,800 lb (5,800 kg) of free-fall conventional bombs and mines, including one free-fall nuclear weapon. Navy crews dubbed the Skywarrior the "Whale" because of its size and less-than-slender appearance. On September 18, 1962, the A3D was redesignated A-3 under the new Tri-Service aircraft designation system. By the end of the 1950s, the strategic bomber role of the Skywarrior was rendered obsolete due to the introduction of the Polaris submarine-launched ballistic missile and the ballistic missile submarines designed to carry them. However, many A-3s would be modified to serve tactical reconnaissance, electronic warfare, and tanker roles. The Skywarrior also happened to form the basis of the Douglas B-66/RB-66 Destroyer medium bomber for the US Air Force, which first flew in June 1954 and of which 294 were built. Like the Skywarrior, the B-66 served as both a bomber, reconnaissance platform, and EW platform during its operational career, but it differed in having ejection seats.
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| Top: Douglas EKA-3B Skywarrior (BuNo 142251) on display at the USS Midway Museum, San Diego Bottom: Douglas EKA-3B (BuNo 147663) in flight, 1971 |
Although the A-3 Skywarrior's career as a nuclear-armed strategic bomber was rather brief given the introduction of SLBMs, it represented a quantum leap forward in the US Navy's efforts to acquire a long-range airborne nuclear weapons delivery system for use from large carriers. Even in situations where the Americans did not use a carrier-based plane to drop a nuclear weapon in anger, the A-3's airframe gave it operational flexibility to be used for electronic warfare, reconnaissance, and tanker missions during the Vietnam War and Operation Desert Storm.
Now all this brings me to discussing one A-3 Skywarrior I saw on the deck of the USS Midway during my visit to the USS Midway Museum in April 2017. Although the A-3 Skywarrior fell out of use as a nuclear-armed strategic bomber after the Polaris SLBM was introduced, the Vietnam War paved the way for the Skywarrior to be used as a tanker aircraft (KA-3B), reconnaissance aircraft (RA-3B), and electronic warfare aircraft (EA-3B, EKA-3B, ERA-3B). The KA-3B had all bombing equipment replaced by a probe-and-drogue system for refueling aircraft, while the EA-3B featured a pressurized compartment in the former weapon bay for one Electronic Warfare Officer and three ESM operators. The RA-3B, on the other hand, had the weapons bay modified to accommodate 12 cameras plus photoflash bombs, and increased pressurization enabled the camera operator to enter the weapons bay to check the cameras. The EKA-3B version that I saw at the USS Midway Museum was designed for a dual tanker/EW role, with the tail turret replaced by a tail fairing with electronic countermeasures (ECM) equipment. A total of 85 A-3Bs were converted to KA-3B iteration, and 34 of them were modified to EKA-3B standard. During the Vietnam War, EA-3Bs and EKA-3Bs were used to jam North Vietnamese radars, as well as refuel tactical aircraft operating over Vietnamese airspace. After the Vietnam War, most of the EKA-3Bs were converted back to KA-3B configuration, and the EKA-3B was replaced in active service by the Grumman KA-6D Intruder (tanker version of the A-6 attack aircraft). The EA-3B was also used during the Cold War for electronic intelligence against Warsaw Pact member states in Eastern Europe, and it served long enough to take part in Operation Desert Storm in early 1991, before being retired from service on September 27 of that year.
References:
Buttler, T., 2010. American Secret Projects: Bombers, Attack, and Anti-Submarine Aircraft 1945 to 1974. Hinckley, UK: Midland Publishing.
Buttler, T., 2021. American Secret Projects 4: Bombers, Attack, and Anti-Submarine Aircraft 1945 to 1974. Manchester, UK: Crécy Publishing.
Francillon, R. J., 1979. McDonnell Douglas Aircraft since 1920, Volume I. Annapolis, MD: Naval Institute Press.Gunston, B., and Gilchrist, P., 1993. Jet Bombers: From the Messerschmitt Me 262 to the Stealth B-2. Oxford, UK: Osprey Publishing. ISBN 1-85532-258-7.
Heinemann, E., 1987. "A Whale of an Airplane." Naval Aviation News 70 (November/December 1987): 18–21.
Zichek, J.A., 2009. The Incredible Attack Aircraft of the USS United States, 1948–1949. Atglen, PA: Schiffer Publishing. ISBN 978-0-7643-3229-6.
