Douglas A-3 Skywarrior
The Douglas A-3 Skywarrior was a strategic bomber built for the United States Navy, and among the longest serving; it entered service in the mid-1950s and was not retired until 1991. For many years after its introduction, it was also the heaviest aircraft ever flown from an aircraft carrier, earning it the unofficial nickname "The Whale". [1] Its primary function for much of its later service life was as an electronic warfare platform and high capacity tanker.
It also served in the USAF until the early 1970s as the B-66 Destroyer. The Skywarrior is the only Navy strategic bomber to enter service, (the Martin P6M SeaMaster tested well but never entered service due to the obsolescence of the flying-boat platform). Later multi-role aircraft like the A-5 Vigilante could also go on strategic missions.
Design and development
Early in World War II, the Navy began to explore the concept of a jet-powered aircraft operating from aircraft carriers. Success encouraged further development of the concept, and early in the post war years the Navy began to consider jet power as a possible means of operating from carriers, aircraft that were large enough to provide a strategic bombing capability.
In January 1948, the Chief of Naval Operations issued a requirement to develop a long-range, carrier-based attack plane that could deliver a 10,000-pound (4,500 kg) bomb load or a nuclear weapon [2]. The contract which the Navy awarded to the Douglas Aircraft Company on 29 September 1949 led to the development and production of the A3D Skywarrior. It was designed by Ed Heinemann, also to win fame for the A-4 Skyhawk. The prototype XA3D-1 first flew on 28 October 1952.
Considerable development problems, largely with the original engines, delayed the introduction of the Skywarrior until spring 1956. The A-3 was by far, the largest and heaviest aircraft ever designed for routine use on an aircraft carrier, though ironically it was the smallest proposal among other proposals which could only be deployed on even larger carriers not yet in service. For storage below deck, the A-3's wings folded upward outboard of the engines, lying almost flat and in order to accommodate the tall tail, it was hinged to starboard [2]. Because of its cumbersome size, and less-than-slender profile, it was nicknamed "The Whale" (after it converted to the electronic warfare role, it became "The Electric Whale"). Production ended in 1961.
Technical description
The Skywarrior had a 36° degree swept wing and two Pratt & Whitney J57 turbojet engines. Although prototypes had used the intended Westinghouse J40, that powerplant proved disastrous, and was subsequently canceled. The turbojets could be supplemented by a provision for 12, 4,500 lbf (20 kN) thrust JATO bottles, allowing takeoff from carriers that did not have catapults. The aircraft had a largely conventional semi-monocoque fuselage, with the engines in underwing nacelles. Flight controls were hydraulic, and both wings and vertical tailfin could fold for carrier stowage. Capacious internal fuel tanks provided long range.
The early A-3 variants had a crew of three: pilot, bombardier/navigator (BN) and gunner. An unusual cockpit configuration was incorporated with the three crew sitting under a framed canopy. In the raised compartment, the pilot and bombardier/navigator sat in a side-by-side arrangement with the pilot's station on port side having full flight controls. On initial variants, a third crew member who acted as a gunner sat behind the duo in an aft-facing seat. Later electronic counter-measures variants could accommodate a crew of seven with flight crew consisting of a pilot, co-pilot and navigator plus four electronic systems operators occupying stations in the sumptuous fuselage [2].
Efforts to reduce weight had led to the deletion of ejection seats during the design process, based on the assumption that most flights would be at high altitude. A similar arrangement with an escape tunnel had been used on the F3D Skyknight. Aircrews began joking morbidly that "A3D" stood for "All Three Dead" (in 1973 the widow of a Skywarrior crewman killed over Vietnam sued the company for not providing ejection seats). Documented history of mechanical failure showed a rate well above average. While there were magazine articles that conjectured that the safety problem was compounded by assigning weaker pilots to slower jets like the A3, during their heyday, Skywarrior pilots were often "best-of-the-best" due to its critical nuclear strike role. [3]
The Skywarrior could carry up to 12,000 lb (5,443 kg) of weaponry in the fuselage bomb bay, which in later marks was used for sensor and camera equipment or additional fuel tanks. An AN/ASB-1A bomb-director system was initially installed, later replaced by a revised AN/ASB-7 with a slightly reshaped nose. Defensive armament was two 20mm cannon in a radar-operated tail turret designed by Westinghouse, usually removed in favor of an aerodynanic tail fairing. While some bombing missions would be carried out early in the Vietnam war, most bombing would be carried out by more nimble attack and fighter bombers, and the Skywarrior would serve mostly as a tanker and electronic warfare support aircraft.
Operational history
Nuclear bomber
Prior to the Polaris-armed submarine, the A-3 was the Navy's critical element in the US nuclear deterrent. The Skywarrior's strategic bombing role faded quickly after 1960, briefly replaced by the A3J Vigilante. Soon after that, the Navy abandoned the concept of carrier-based strategic nuclear weaponry with the success of the Polaris program.
Vietnam
Skywarriors saw some use in the conventional bombing and mine-laying role during the Vietnam War from 1965 through 1967. The Navy would soon use only more nimble fighter sized attack bombers over Vietnam, but it found subsequent service in the tanker, photographic reconnaissance, and electronic warfare roles. The Skywarrior would not only extend the range of a strike force, but save returning pilots short on fuel, much like the larger and more famous KC-135 Stratotanker.
Tanker role
During Vietnam, the Skywarrior was modified into a multimission tanker variant (EKA-3B) that was a real workhorse for the carrier air wing. Buddy tanking using A-4 Skyhawks, and inflight refueling using A-3 Skywarriors was utilized by the US Navy in the Vietnam theater of operations from at least 1966 through 1970. Eventually, the EKA-3B was replaced by the smaller dedicated KA-6D Intruder tanker, which had less capacity and endurance, and later by the S-3 Viking which had even less fuel capacity. With the ongoing retirement of the S-3B, future tanking will be accomplished by F/A-18E and F mission tankers.
Cold War
The EA-3 variant was an indispensable resource for the Fleet Commander and was used in critical ELINT role operating from aircraft carrier decks and ashore supplementing the larger EP-3. Its last service was as an ELINT platform during Desert Storm.
Spy plane
The EA-3B model was modified for electronic intelligence against the Warsaw Pact. Missions were flown around the globe beginning in 1956, with the B-47 flying a similar mission. It carried a crew of seven, with flight crew of three in the cockpit and four electronic systems operators in the converted weapons bay. It offered unique electronic reconnaissance capabilities in numerous Cold War-era conflicts and the Vietnam War.[4]
Retirement
For more than two decades, the 282 Skywarriors the Navy procured served effectively in many roles with the last USN Skywarriors retiring on 27 September 1991. RDT&E units, notably Point Mugu and China Lake, attempted to retain their A-3 testbeds. VADM Dunleavy, as Deputy Chief of Naval Operations for Air Warfare, and an old A-3 navigator himself, regretfully made the decision final.
Post-retirement career
In the agreement Hughes had with the Navy, the Navy had agreed to retain at least one aircraft in inviolate storage at Davis-Monthan for long term parts support for major structural parts. Westinghouse also operated an A-3 in a similar arrangement.
The NAVAIR Weapons System Manager, who participated in the drafting of the contract, saw that support as no longer possible, and Hughes was contacted to meet with Westinghouse and Raytheon to finalize plans for the support shutdown of the aircraft. At the last Integrated Logistics meeting at Alameda, both Raytheon and Hughes indicated their willingness to obtain fleet assets vice sending them to Davis-Monthan, thereby saving the airframes from destruction and saving the Navy the cost of storage at AMARC.
As the plan matured, two other contractors, Thunderbird Aviation and CTAS also elected to participate in similar agreements. The fleet spares from ASO were distributed between the contractors evenly, and warehouses were emptied all over the United States. Unfortunately, due to misunderstandings and reorganizations within the Navy, the world wide ASO assets were scrapped, not getting to the contractors. In early 1993, CTAS decided that they no longer had use for their aircraft, and Hughes had several programs needing additional assets.
In early 1994, a USAF program decided to modify an A-3 for F-15 Radar tests, and the only available airframe was stored at Alameda since the fleet shutdown. Hughes added that aircraft to the bailment, and ferried the aircraft to Van Nuys for modifications. An entire nose section was removed from a stricken F-15B at Davis-Monthan, and grafted onto the front of the aircraft. Racks and equipment were installed in the cabin, and the aircraft is utilized by Hughes and the USAF for F-15 software development.
In 1994 Westinghouse decided to terminate their agreement with the Navy, and Thunderbird added their aircraft to the Thunderbird bailment. In 1996, Thunderbird Aviation went into receivership, and Hughes, through mutual cost savings to the Government, added the Thunderbird assets to the contract, prepping them for ferry at Deer Valley airport, and relocating them to Mojave, California and Tucson, Arizona for long term storage.
In December, 1996, Raytheon bought the aerospace units of Hughes Aircraft Company. Hughes Aeronautical Operations, now a part of Raytheon Systems, continues to operate the A-3s from their base at Van Nuys Airport, CA. These aircraft participated at several military air shows, telling visitors that the plane continued to be valuable for its load capacity compared to corporate jets, and performance compared to small airliners.
B-66 Destroyer
The US Air Force ordered 294 of the derivative B-66 Destroyer, most of which were used in the reconnaissance and electronic warfare roles. The Destroyer was fitted with ejection seats, but did not have a primary refueling role as did its naval counterpart.
Raytheon still flew the Skywarrior in the late '90s as a test platform, retained because of its volume, capacity, and high performance compared to business jets or airliner airframes.
Variants
Note: under the original Navy designation scheme, the Skywarrior was designated A3D (i.e., third Attack aircraft from Douglas Aircraft). In September 1962 the new Tri-Services designation system was implemented and the aircraft was redesignated A-3. Where applicable, pre-1962 designations are listed first, post-1962 designations in parentheses.
- XA3D-1: Two prototypes with Westinghouse J40 turbojets, no cannon in tail turret.
- YA3D-1 (YA-3A): One pre-production prototype with Pratt & Whitney J57 engines. Later used for tests at the Naval Air Missile Test Center.
- A3D-1 (A-3A): 49 initial production versions, serving largely in developmental role in carrier service.
- A3D-1P (RA-3A): One A3D-1 converted as a prototype for the A3D-2 with camera pack in the weapon bay.
- A3D-1Q (EA-3A): Five A3D-1s converted for the electronic reconnaissance (ELINT) role, with ECM equipment and four operators in weapons bay.
- A3D-2 (A-3B): Definitive production bomber version, with stronger airframe, more powerful engines, slightly larger wing area (812 ft² versus 779 ft²), provision for in-flight refueling reel for tanker role. Final 21 built had new AN/ASB-7 bombing system, reshaped nose; deleted tail turret in favor of electronic warfare installation.
- A3D-2P (RA-3B): 30 photo-reconnaissance aircraft with weapons bay package for up to 12 cameras plus photoflash bombs. Increased pressurization allowed camera operator to enter the bay to check the cameras. Some retained tail guns, but most were later converted to ECM tail of late A-3Bs.
- A3D-2C (EA-3B): 24 electronic warfare versions with pressurized compartment in former weapon bay for three ECM operators, various sensors. Some early models had tail guns, but these were replaced with the ECM tail. The EA-3B was generally assigned to fleet reconnaissance squadrons (VQ). It served in the fleet for almost 40 years, and has been replaced with the ES-3A Shadow.
- A3D-2T (TA-3B): 12 bomber-trainer versions. Five later converted as VIP transports (two redesignated UTA-3B).
- KA-3B: 85 A-3B bombers refitted in 1967 for the tanker role with probe-and-drogue system in place of bombing equipment.
- EKA-3B: 34 KA-3B tankers refitted for dual ECM/tanker role, with electronic warfare equipment and tail fairing in place of rear turret. Most were converted back to KA-3B configuration (with no ECM gear) after 1975.
- ERA-3B: Eight RA-3Bs converted as electronic aggressor SEAD aircraft with ECM in new tail cone, ventral fairing, cylindrical fairing atop vertical fin, and wing tips. Added chaff dispensers and two ram-air turbines to power the new equipment. Crew increased to five with addition of two ECM evaluators in a pressurized cabin in the bomb bay.
- NRA-3B: Six RA-3Bs converted for various non-combat test purposes.
- VA-3B: One EA-3B converted as a VIP transport.
Operators
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Specifications (A3D-2/A-3B Skywarrior)
General characteristics
- Crew: 3
Performance
- Thrust/weight: 0.30
Armament
- Guns: 2× 20 mm (0.787 in) cannon in tail turret
- Bombs: 12,000 lb (5,400 kg) of free-fall bombs, including any combination of
- 12× 500 lb (230 kg) Mark 82 bombs or
- 6× 1,000 lb (450 kg) Mark 83 bombs or
- 1,600 lb armor-piercing bombs or
- 500 lb Mark 50 bombs or
- 1,000 lb Mark 36 bombs or
- 2,000 lb Mark 25 mines or
- 1× Mark 15 free-fall nuclear weapon
References
- Donald, David and Lake, Jon, eds. Encyclopedia of World Military Aircraft. London: AIRtime Publishing, 1996. ISBN 1-880588-24-2.
- Winchester, Jim, ed. "Douglas A-3 Skywarrior." Military Aircraft of the Cold War (The Aviation Factfile). London: Grange Books plc, 2006. ISBN 1-84013-929-3.
External links
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