| A-5 (A3J) Vigilante | |
|---|---|
| Role | Nuclear strike bomber, reconnaissance aircraft |
| Manufacturer | North American Aviation |
| First flight | 31 August 1958 |
| Introduction | June 1961 |
| Retired | January 1980 |
| Primary user | United States Navy |
| Produced | 1956-1963 1968-1970 |
| Number built | 156 |
The North American A-5 Vigilante was a carrier-based supersonic bomber designed for the United States Navy. Its service in the nuclear strike role to replace the A-3 Skywarrior was very short; however, as the RA-5C, it saw extensive service during the Vietnam War in the tactical strike reconnaissance role. Prior to the unification of the Navy designation sequence with the Air Force sequence in 1962, it was designated the A3J Vigilante.[1]
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In 1953, North American Aviation began a private study for a carrier-based, long-range, all-weather strike bomber, capable of delivering nuclear weapons at supersonic speeds.[2] This proposal, the NAGPAW (North American General Purpose Attack Weapon) concept, was accepted by the United States Navy, with some revisions, in 1955.[3] A contract was awarded on 29 August 1956. Its first flight occurred two years later on 31 August 1958 in Columbus, Ohio.[4]
At the time of its introduction, the Vigilante was one of the largest and by far the most complex aircraft to operate from a United States Navy aircraft carrier. It had a high-mounted swept wing with a boundary-layer control system (blown flaps) to improve low-speed lift.[4] There were no ailerons. Roll control was provided by spoilers in conjunction with differential deflection of the all-moving tail surfaces. Use of aluminum-lithium alloy for wing skins and titanium for critical structures were also unusual. The A-5 had two widely-spaced General Electric J79 turbojet engines (the same as used on the McDonnell Douglas F-4 Phantom II fighter), and a single large all-moving vertical stabilizer.[2] Preliminary design studies had employed twin vertical fin/rudders.[4] The wings, vertical stabilizer and the nose radome folded for carrier stowage. The Vigilante had a crew of two seated in tandem, a pilot and a bombardier-navigator (BN)—reconnaissance/attack navigator (RAN) on later recon versions— in individual ejection seats.[1]
Despite being designated by the US Navy as a "heavy", the A-5 was surprisingly agile for such a large aircraft, without the drag of bombs or missiles, even escorting fighters found that the clean airframe and powerful engines made the Vigilante very fast at high and low altitudes. However, its high approach speed and high angle of attack in the landing configuration made returning to the aircraft carrier a challenge for inexperienced or unwary pilots.[5]
The Vigilante had advanced and complex electronics when it first entered service. It had one of the first fly-by-wire systems of an operational aircraft (with mechanical/hydraulic backup) and a computerized AN/ASB-12 nav/attack system incorporating a head-up display (Pilot's Projected Display Indicator (PPDI), one of the first), multi-mode radar, Radar-Equipped Inertial Navigation System (REINS, based on technologies developed for the Navaho missile), closed-circuit television camera under the nose, and an early digital computer known as VERDAN (Versatile Digital Analyzer) to run it all.
Given its original design as a carrier-based, supersonic, nuclear heavy attack aircraft, the Vigilante's main armament was carried in a novel "linear bomb bay" between the engines in the rear fuselage, which provided for positive separation of the bomb from the aircraft at supersonic speeds. The single nuclear weapon, commonly the Mk 28 bomb, was attached to two disposable fuel tanks in the cylindrical bay in an assembly known as the "stores train". A set of extendable fins was attached to the aft end of the most rearward fuel tank. These fuel tanks were to be emptied during flight to the target and then jettisoned with the bomb by an explosive drogue gun. The stores train was propelled rearward at about 50 feet per second (30 knots) relative to the aircraft, not at the aircraft's forward speed as stated in some references. It therefore followed a typical ballistic arc rather than "falling straight down." [6]
In practice the system was not reliable and no live weapons were ever carried in the linear bomb bay. In the RA-5C configuration, the bay was used solely for fuel. On three occasions the shock of the catapult launch caused the fuel cans to eject onto the deck resulting in one aircraft loss.[7]
The Vigilante originally had two wing pylons, intended primarily for drop tanks. The second Vigilante variant, the A3J-2 (A-5B), incorporated internal tanks for an additional 460 gallons of fuel (which added a pronounced dorsal "hump") along with two additional wing hardpoints, for a total of four. In practice the hardpoints were rarely used. Other improvements included blown flaps on the leading edge of the wing and sturdier landing gear.
The reconnaissance version of the Vigilante, the RA-5C, had slightly greater wing area and added a long canoe-shaped fairing under the fuselage for a multi-sensor reconnaissance pack. This added an APD-7 side-looking airborne radar (SLAR), AAS-21 infrared linescanner, and camera packs, as well as improved ECM. An AN/ALQ-61 electronic intelligence system could also be carried. The RA-5C retained the AN/ASB-12 bombing system, and could, in theory, carry weapons, although it never did in service. Later-build RA-5Cs had more powerful J79-10 engines with afterburning thrust of 17,900 lbf (80 kN). The reconnaissance Vigilante weighed almost five tons more than the strike version with almost the same thrust and an only modestly enlarged wing. These changes cost it acceleration and climb rate, though it remained fast in level flight.
Designated A3J-1, the Vigilante first entered squadron service with Heavy Attack Squadron THREE (VAH-3) in June 1961 at Naval Air Station Sanford, Florida, replacing the A-3 Skywarrior in the heavy attack role.[8] All variants of the Vigilante were built at North American Aviation's facility at Port Columbus Airport in Columbus, Ohio, alongside the T-2 Buckeye and OV-10 Bronco.
Under the Tri-Services Designation plan implemented under Robert McNamara in September 1962, the Vigilante was redesignated A-5, with the initial A3J-1 becoming A-5A and the updated A3J-2 becoming A-5B. The subsequent reconnaissance version, originally A3J-3P, became the RA-5C.
The Vigilante's early service proved troublesome, with many teething problems for its advanced systems. Although these systems were highly sophisticated, the technology of the time was in its infancy, and its reliability was poor. In early squadron service, the MTBF (Mean Time Between Failures) for some systems was sometimes as short as 15 minutes. Although most of these reliability issues were eventually worked out as maintenance personnel gained greater experience with supporting these systems, the aircraft tended to remain a maintenance-intensive platform throughout its career.
The A-5's service coincided with a major policy shift in the U.S. Navy's strategic role, which switched to emphasize submarine launched ballistic missiles rather than manned bombers. As a result, in 1963, procurement of the A-5 was ended and the type was converted to the fast reconnaissance role. The first RA-5C's were delivered to the Replacement Air Group (RAG)/Fleet Replacement Squadron (FRS), redesignated as Reconnaissance Attack Squadron THREE (RVAH-3) at NAS Sanford, Florida in July 1963, with all Vigilante squadrons subsequently redesignated RVAH. Under the cognizance of Reconnaissance Attack Wing ONE, a total of 10 RA-5C squadrons were ultimately commissioned. RVAH-3 continued to be responsible for the stateside-based RA-5C training mission of both flight crews, maintenance and support personnel, while RVAH-1, RVAH-5, RVAH-6, RVAH-7, RVAH-9, RVAH-11, RVAH-12, RVAH-13 and RVAH-14 routinely deployed aboard Forrestal, Saratoga, Ranger, Independence, Kitty Hawk, Constellation, Enterprise, America, John F. Kennedy and eventually Nimitz-class aircraft carriers to the Atlantic, Mediterranean and Western Pacific.
Eight of 10 squadrons of RA-5C Vigilantes also saw extensive service in Vietnam starting in August 1964, carrying out hazardous medium-level reconnaissance missions. Although it proved fast and agile, 18 RA-5Cs were lost in combat: 14 to anti-aircraft fire, three to surface-to-air missiles, and one to a MiG-21 during Operation Linebacker II. Nine more were lost in operational accidents while serving with Task Force 77. Due, in part, to these combat losses, 36 additional RA-5C aircraft were built from 1968–1970 as attrition replacements.[9]
In 1968, Congress closed the aircraft's original operating base of NAS Sanford, Florida and transferred the parent wing, Reconnaissance Attack Wing ONE, all subordinate squadrons and all aircraft and personnel to Turner AFB, a Strategic Air Command (SAC) B-52 and Boeing KC-135 base in Albany, Georgia. The tenant SAC bomb wing was then deactivated and control of Turner AFB was transferred from the Air Force to the Navy with the installation renamed NAS Albany. In 1974, after barely six years of service as a naval air station, Congress opted to close NAS Albany as part of a post-Vietnam force reduction, transferring all RA-5C units and personnel to NAS Key West, Florida.
Despite the Vigilante's useful service, it was expensive and complex to operate and occupied significant amounts of precious flight deck and hangar deck space aboard both conventional and nuclear-powered aircraft carriers. With the end of the Vietnam War, disestablishment of RVAH squadrons began in 1974, with the last Vigilante squadron, RVAH-7, completing its final deployment to the Western Pacific aboard USS Ranger (CV-61) in late 1979. The final flight by an RA-5C took place on 20 November 1979 when a Vigilante departed NAS Key West, Florida.[10] Reconnaissance Attack Wing ONE was subsequently disestablished at NAS Key West, Florida in January 1980.
The Vigilante did not end the career of the A-3 Skywarriors, which would carry on as electronic warfare platforms and tankers, designated as EA-3B and KA-3B, into the 1980s and early 1990s.
Fighters replaced the RA-5C in the carrier-based reconnaissance role. The RF-8G version of the F-8 Crusader, modified with internal cameras, had already been serving in two light photographic squadrons (VFP-62 and VFP-63) since the early 1960s, operating from older aircraft carriers unable to support the Vigilante. The Marine Corps' sole photographic squadron (VMFP-3) would also deploy aboard aircraft carriers during this period with RF-4B Phantom II aircraft. These squadrons superseded the Vigilante's role by providing detachments from the primary squadron to carrier air wings throughout the late 1970s and early-to-mid-1980s until transfer of the recon mission to the Navy's fighter squadron (VF) community operating the Grumman F-14 Tomcat.
Select models of the F-14 Tomcat would eventually carry the multi-sensor Tactical Air Reconnaissance Pod (TARPS) and the Digital Tactical Air Reconnaissance Pod (D-TARPS). Following up to present day, the weight of fighters such as the F-14 Tomcat and F/A-18E/F Super Hornet have evolved into the same 62,950 lb (28,550 kg) class as the Vigilante. With the retirement of the F-14, the F/A-18E and F/A-18F Super Hornet strike fighters and EA-18G Growler electronic warfare aircraft are planned to cover the strike, reconnaissance, tanker and electronic warfare roles of the F-14 Tomcat, A-6E Intruder, A-7E Corsair II, RF-8G Crusader, RA-5C, KA-6D Intruder, Grumman EA-6B Prowler. S-3B Viking, ES-3A Shadow and EA-3B Skywarrior.
While the Vigilante served in the attack and reconnaissance roles, its design and planform was a direct descendant of the earlier WS-202 or XF-108 Rapier Mach 3 fighter, designed originally to escort the North American XB-70 Valkyrie bomber. Although both experimental programs were ultimately unsuccessful, the Soviet's MiG-25 "Foxbat" interceptor was greatly influenced by American advances in high speed flight.[11] [N 1] Although there is a superficial resemblance to the F-108/Vigilante configuration, the MiG-25 was an entirely unique design.[12]
On 13 December 1960, Navy Commander Leroy Heath (Pilot) and Lieutenant Larry Monroe (Bombardier/Navigator) established a world altitude record of 91,450.8 feet (27,874.2 m) in an A3J Vigilante carrying a 1,000 kilogram payload, beating the previous record by over four miles (6 km). This new record held for over 13 years.[4]
Data from North American Rockwell A3J (A-5) Vigilante,[14] Combat Aircraft since 1945[15]
General characteristics
Performance
Armament
Avionics
Systems carried by A-5 or RA-5C[17][18]
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