A-5 Vigilante: Wikis

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A-5 (A3J) Vigilante
Role Nuclear strike bomber, reconnaissance aircraft
Manufacturer North American Aviation
First flight 31 August 1958
Introduced June 1961
Retired January 1980
Primary user United States Navy
Produced 1956-1963
1968-1970
Number built 158

The North American A-5 Vigilante was a powerful, highly advanced 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]

Contents

Design and development

An A3J-1 during trials on USS Saratoga, 1960.

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, as well as being used instead of conventional ailerons. [4]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 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]

A YA-5C prototype, 1963

The Vigilante had extremely 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 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 was intended to make bomb delivery safer for the flight crew and more accurate. When conventional bombers "drop" a bomb, the bomb falls downward, but continues forward at the same speed as the aircraft. [2] This requires pilot and navigator/bombardier skill and complicated equipment to place a bomb on its intended target. The linear bomb bay would eject the payload rearward at approximately the same speed as the forward velocity of the aircraft, causing the bomb to "stand still" and drop straight down. No calculation is needed - the bomb falls at the point at which it was dropped. As an added benefit, the aircraft is rapidly moving away from the dropped bomb, enabling lower drop altitudes or safer drops from higher altitudes.[6]

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." The idea was for the fuel tanks to be emptied during flight to the target and then jettisoned as part of the bomb by an explosive drogue gun. In practice the system was never 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]

An overhead aerial view of an RA-5C Vigilante aircraft.

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 -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.

Operational history

A-5As of VAH-7 on USS Enterprise in 1962.

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. 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.

An RVAH-12 RA-5C beginning its reconnaissance run over Vietnam, 1967.

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. [8]

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 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. Reconnaissance Attack Wing ONE was subsequently disestablished at NAS Key West, Florida in January 1980.

RA-5C Vigilante, BuNo 156608, from Reconnaissance Attack Squadron 7 (RVAH-7) during what may have been its final flight in 1979. This aircraft is now on permanent display at Naval Support Activity Mid-South (formerly NAS Memphis), TN.
Retired Vigilantes in the Arizona desert.

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 (VF) operating the 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, EA-6B Prowler. S-3B Viking, ES-3A Shadow and EA-3B Skywarrior.

Although the Vigilante served in the attack and reconnaissance roles, its design and configuration was believed to be a major influence on one of the world's most famous postwar interceptors: the Soviet MiG-25 "Foxbat".[9] The MiG-25 would look even more familiar if the Vigilante had retained the twin vertical fins of the prototype; although North American originally specified two fins, that part of the design was vetoed by the Navy in favor of one folding tailfin. Dual tailfins would become part of the U.S. Navy's F-14 Tomcat, the US Navy's and U.S. Marine Corps' F/A-18 Hornet) and the U.S. Air Force's F-15 Eagle and F-22 Raptor. The F-14, F-15 Eagle and other Western aircraft would also adopt a high mounted wing and wedge-shaped intake geometry (i.e., wedged air inlets) that were incorporated in the RA-5C.

Records

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, besting the previous record by over four miles (6 km). This new record held for over 13 years.[4]

Variants

XA3J-1
Prototypes, two built.
A-5A (A3J-1)
production nuclear bomber variant. 59 built, 43 converted to RA-5C.
A-5B (A3J-2)
Nuclear bomber with greater range. None completed (see YA-5C).
YA-5C (XA3J-3P)
Six A-5Bs converted as reconnaissance prototyped before completion.
RA-5C (A3J-3P)
Reconnaissance version, 91 new-build plus 43 converted A-5As.
NR-349 Retaliator
Proposed Improved Manned Interceptor (IMI) for U.S. Air Force with two, later three engines and an armament of six AIM-54 Phoenix missiles.

Survivors

RA-5C BuNo 156624 is preserved at the National Museum of Naval Aviation.
RA-5C BuNo 151629 on display at the Pueblo Weisbrod Aircraft Museum in Pueblo, Colorado in November 2007.
RA-5C Vigilante, BuNo 156632, on display at Orlando Sanford International Airport (former NAS Sanford) in late March 2008

Several Vigilantes are currently stored or on display in the United States.

Operators

 United States

Specifications (A-5A Vigilante)

Orthographically projected diagram of the A-5A Vigilante.

General characteristics

  • Crew: 2
  • Length: 76 ft 6 in (23.32 m)
  • Wingspan: 53 ft 0 in (16.15 m)
  • Height: 19 ft 5 in (5.9 m)
  • Wing area: 754 ft² (70 m²)
  • Empty weight: 32,700 lb (14,800 kg)
  • Loaded weight: 47,530 lb (21,580 kg)
  • Useful load: 30,250 lb (13,730 kg)
  • Max takeoff weight: 62,950 lb (28,580 kg)
  • Powerplant:General Electric J79-GE-8 afterburning turbojets
    • Dry thrust: 10,900 lbf (48 kN) each
    • Thrust with afterburner: 17,000 lbf (76 kN) each

Performance

Armament

See also

Comparable aircraft

Related lists

References

Notes
  1. ^ a b Wagner 1982, p. 361.
  2. ^ a b c Dean 2001, p. 23.
  3. ^ Siuru 1981, p. 15.
  4. ^ a b c d Siuru 1981, p. 16.
  5. ^ Ellis 2008, p. 64.
  6. ^ Ellis 2008, pp. 57–58.
  7. ^ Goebel, Greg. "The North American A-5/RA-5 Vigilante." vectorsite.net, 5 April 2007. Retrieved: 2 March 2008.
  8. ^ Ellis 2008, p. 63.
  9. ^ [Discovery Channel documentary "Wings of the Red Star" on the Mig-25]
Bibliography
  • Dean, Jack. "Sleek Snooper." Airpower, Volume 31, No. 2, March 2001.
  • Donald, David and Jon Lake, eds. Encyclopedia of World Military Aircraft. London: AIRtime Publishing, 1996. ISBN 1-880588-24-2.
  • Ellis, Ken, ed. "North American A-5 Vigilante" (In Focus). Flypast, August 2008.
  • Gunston, Bill. Bombers of the West. London: Ian Allan Ltd., 1973, pp. 227–235. ISBN 0-7110-0456-0.
  • Powell, Robert. RA-5C Vigilante Units in Combat. London: Osprey Publishing Ltd., 2004. ISBN 1-84176-749-2.
  • Siuru, William. "Vigilante: Farewell to the Fleet's Last Strategic Bomber!" Airpower, Volume 11, No. 1, January 1981.
  • Taylor, John W.R. "North American A-5 Vigilante." Combat Aircraft of the World from 1909 to the Present. New York: G.P. Putnam's Sons, 1969. ISBN 0-425-03633-2.
  • Wagner, Ray. American Combat Planes. Garden City, NY: Doubleday & Company, third edition 1982, ISBN 0-385-13120-8

External links

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