After the World War II, the time called "Cold War" has begun - when the United States competed with the Soviet Union, with the aim, if not to control the world then at least to keep the peace. This has led to an arms race under such conditions that both sides possessed nuclear weapons, but the problem remained to deliver them to the targets on enemy’s territory. On the US side an important participant in the arms race was the Navy. In the late 40s a realistic idea of delivery of a nuclear weapon was to do it on board of a bomber, taking off of an aircraft carrier – which meant it would have to cover a smaller distance. Initially, it appeared that the aircraft that could deliver a load of 10,000 pounds (4 536 kg) over a distance of 1,500 miles (2 414 km) would have to weigh between 130 000 and 200 000 pounds (59 000 and 90 700 kg) - the weight that even a new super-carrier USS United States designed then would not be able to handle. The Chief Engineer of the Douglas company, Ed Heinemann began consideration of a new type of aircraft by checking the weight limit of the aircraft, that the aircraft carriers in use at that time (1948) were able to handle. It turned out that it was a maximum of 68 000 pounds (30 844 kg).
In March of 1948 in Washington Heinemann presented preliminary sketches of the new bomber - one was a turboprop-powered design weighing 80 000 pounds (36 290 kg) and the other, jet-powered, weighing 70 000 pounds (31 750 kg). In August 1948 the US Navy sent an invitation to 14 aviation companies, to submit offers for a bomber with a weight not exceeding 100 000 pounds (45 360 kg). Although the Navy favored a project of a turboprop aircraft, not trusting the jet drive, Ed Heinemann was convinced that he would be able to design a jet bomber within the mass limits such as imposed by existing carriers. This way the concept of the Douglas Model 593 was born. At the end of 1948 the companies: Douglas, Curtiss Martin, Consolidated, and Fairchild Republic submitted their proposals. The companies Douglas and Curtiss were selected for further trials in March 1949. Douglas started the design work immediately. Their result was a jet driven twin-engine high-wing aircraft with a maximum take-off weight of 70 000 pounds (31 750 kg) and a top speed of 507 knots (939 km/h) at an altitude of 40 000 feet (12 190 m). The Navy requested the bomb bay with a width of 66 inches (1 676 mm) to fit the latest atomic bomb in. During the design process, due to delays from the supplier the Westinghouse J40 engines were replaced by Pratt & Whitney J57s. Thanks to the placing of the engines in nacelles under the wings, the change was feasible without major modifications to the structure of the aircraft.
In February 1951 years the Navy ordered the first aircraft from the Douglas company, designated A3D-1. The prototype aircraft of this type (XA3D-1) made its first flight on October 28, 1952, from Edwards Air Force Base, where it was previously assembled from parts transported by truck from the Douglas El Segundo plant. Behind the controls sat the Douglas’ company test pilot, George Jansen, and he was accompanied by the engineer, Walter Kent. The flight program was initially troubled by problems with the electrical, hydraulic and fuel systems, as well as the landing gear and the bomb bay. These problems were solved with time and the first production aircraft A3D-1 took off from Los Angeles International Airport (Douglas plants were located right next door) on September 16, 1953. At the same time the test results encouraged the Douglas company to further develop the aircraft, resulting in another variant, designated A3D-2. Aircraft of this version have strengthened airframes, more powerful engines and were adapted for aerial refueling (getting fuel from another aircraft). 50 airframes of the first variant (A3D-1) were built. Of the second version - A3D-2 – there were 164 bombers made, as well as additional specialized aircraft (the so-called. Versions) - 30 reconnaissance A3D-2P and 24 electronic warfare aircraft A3D-2Q.
In 1962 the US Department of Defense introduced a new, unified designation system for all U.S. military aircraft. Before 1962, the armed services used separate nomenclature systems. Accordingly, all the A3D variants were redesignated. Those old and new designations are summarized in the table below:
|Old designation||New designation||Description|
|A3D-1||A-3A||Initial bomber variant. 49 Aircraft manufactured. Crew – three people|
|A3D-1P||A prototype of the photographic variant. 1 airplane rebuilt from A3D-1|
|A3D-1Q||EA-3A||A variant of an electronic warfare aircraft. 5 converted from A3D-1. Crew - seven people, four of which were accommodated in the bomb bay|
|A3D-2||A-3B||Basic bomber variant. 164 aircraft manufactured. Crew – three people|
|A3D-2P||RA-3B||Photographic version, built from scratch - a big difference compared to the bomber. 30 aircraft manufactured. Crew - three people|
|A3D-2Q||EA-3B||Electronic warfare version, built from scratch - a big difference compared to the bomber. EA-3Bs remained in service for over 40 years. 25 aircraft manufactured. The crew - seven people|
|A3D-2T||TA-3B||Training version, for training bombardiers, built from scratch - a big difference compared to the bomber. 12 aircraft manufactured. Crew - eight people, including five students|
|KA-3B||A tanker, rebuilt the A-3B bomber. Crew - three people|
|EKA-3B||Dual mission - tanker and electronic warfare aircraft, rebuilt from the A-3B bomber. Crew - three people|
|UTA-3B||Passenger and supply version, including the transport of VIP passengers. Rebuilt TA-3B trainers. Five machines were rebuilt, only two bore the designation UTA-3B|
|A3D-2Q||VA-3B||VIP passenger transport version, 1 aircraft rebuilt from A3D-2Q electronic warfare version. Crew of two people, would take up to 14 passengers|
|ERA-3B||Specialized electronic-warfare aircraft, serving as the "aggressor" in naval exercises. 8 rebuilt from RA-3Bs. Crew - four people|
|NRA-3B||Different configurations of test and experimental aircraft. 6 machines repeatedly rebuilt and modified based on the RA-3B version|
|NTA-3B||Experimental aircraft rebuilt and modified from the TA-3B, used by Raytheon for testing the radar being developed for the F-14D Tomcat|
In 1968, the ongoing war in Vietnam caused more and more A-3B bombers were used exclusively as tankers, after the installation of removable roll of hose to transfer fuel to other aircraft. The desire to increase the capacity on this mission prompted the development of a modification of the aircraft, involving the removal of all bombing equipment, installation of additional fuel tanks and a hose reel for refueling in the air. Unlike the previous tanker aircraft, the new version’s refueling equipment was installed permanently. The resulting variant of the aircraft was designated KA-3B. 85 aircraft of this type was created by the remanufacturing of the A-3B bombers at the NARF (Naval Aircraft Rework Facility) Alameda plant. KA-3B could carry about 5 000 gallons (19 000 liters) of aviation fuel and was served by a crew of three men. Externally the aircraft showed only little differences compared to the A-3B, the most distinct was the fairing under the fuselage housing the stowed refueling drogue at the end of the hose.
At the same time, five A-3B bombers, were converted to the EKA-3B variant - also at the NARF Alameda plant – those aircraft were modified both for aerial refueling of other aircraft, but also for electronic warfare. Later, 34 KA-3B aircraft were also rebuilt to this version. Although the mission scope of the aircraft was greatly expanded, the crew still consisted of three people. Externally the aircraft featured four large teardrop-shaped electronic equipment pods or “blisters” on the sides and one “canoe” pod beneath the hull. After the Grumman EA-6B Prowler were put into service as an electronic warfare aircraft, many EKA-3B’s were stripped of most of their electronic equipment and they were used only as tankers.
My model of the EKA-3B depicts an aircraft with the BuNo 142403 wearing the markings of VAQ-131, as seen on board of the aircraft carrier USS Kitty Hawk from November 1968 until June 1969 carrying out missions over the Tonkin Gulf
|Length:||23 770 mm|
|Wing span:||22 100 mm|
|Empty weight:||17 970 kg|
|Maximum takeoff weight:||38 000 kg|
|Propulsion:||Two Pratt & Whitney J57-P-10 jet engines with 4670 daN thrust (5530 daN with water injection)|
|Armament:||None. Equipment for electronic inteligence gathering, countermeasures and in flight refuelling.|
|Max speed:||999 km/h on sea level|