North American A-5 Vigilante

Summary

Description

Development of the A-5 started in 1954 as a private venture by North American Aviation (NAA), who sought to produce a capable supersonic long-distance bomber as a successor to the North American XA2J Super Savage. This conceptual carrier-based, long-range, all-weather strike bomber was designed for supersonic speeds while carrying a sizable payload. The twin-engined aircraft featured a high-mounted wing and numerous advanced technology features, including being the first supersonic bomber designed with a slim forward fuselage and the first with fully-variable wedge-type side air intakes. It incorporated several innovative features, such as being the first bomber to feature a digital computer, and its ability to attain speeds of up to Mach 2 while carrying a nuclear strike payload was relatively ambitious for the era. The US Navy recognized the potential of such a bomber, leading to a contract for its full development and production being issued to the firm on 29 August 1956. One of the prototypes performed the type's maiden flight from Columbus, Ohio, on 31 August 1958.

The North American A-5 Vigilante was furnished with a high-mounted swept wing, incorporating a boundary-layer control system to improve low-speed lift. Aluminum-lithium alloy was used for wing skins and titanium for critical structures, with gold coating used on key areas like the bomb bay to reflect heat. Roll control was achieved via spoilers combined with differential deflection of the all-moving tail surfaces, paired with a relatively large all-moving single vertical stabilizer, doing away with the need for ailerons. To facilitate aircraft carrier operations, the wings, vertical stabilizer, and nose radome were all designed to be folded. Air was supplied to the two General Electric J79 turbojet engines through inlets with variable intake ramps.

The electronics of the Vigilante were relatively advanced, incorporating one of the first "fly-by-wire" systems on an operational aircraft, along with a mechanical/hydraulic backup. The avionics included a computerized AN/ASB-12 nav/attack system with a head-up display, multi-mode radar, a radar-equipped inertial navigation system, a closed-circuit television camera under the nose, and an early digital computer known as "Versatile Digital Analyzer" (VERDAN). The Vigilante was operated by a crew of two: a pilot and a bombardier-navigator seated in tandem, who were provided with North American HS-1A ejection seats.

As a carrier-based supersonic bomber, the Vigilante's primary armament was a single nuclear weapon, typically the Mk 28 bomb, housed in a "linear bomb bay" situated between the engines in the rear fuselage, designed to facilitate bomb release at supersonic speeds. This internal bay accommodated a "stores train" comprising the nuclear weapon attached to two disposable fuel tanks, which were to be jettisoned along with the bomb after emptying. Extendable fins on the aft end of the rearmost fuel tank provided stability during the ballistic trajectory of the stores train after ejection. This system proved unreliable in practice, and live weapons were never carried in the linear bomb bay; instead, the space was repurposed for additional fuel carriage in the RA-5C reconnaissance variant. Early production models also featured a pair of wing pylons primarily intended for drop tanks, while the A3J-2 (A-5B) variant increased this to four hardpoints and incorporated additional internal fuel tanks. These hardpoints could theoretically carry bombs such as the B43, Mark 83, or Mark 84, but were rarely utilized in operational service.

Designated A3J-1, the Vigilante entered service in June 1961, replacing the Douglas A-3 Skywarrior in the strategic nuclear strike role. The Vigilante's early service proved troublesome, with many teething problems with its advanced systems due to the infancy of the technology, making it a maintenance-intensive platform throughout its career. In 1963, procurement of the A-5 was ended, and the type was converted to the fast reconnaissance role, designated RA-5C. Eight of ten squadrons of RA-5C Vigilantes saw extensive service in the Vietnam War starting in August 1964, carrying out hazardous medium-level post-strike reconnaissance missions. Although it proved fast and agile, 18 RA-5Cs were lost in combat. 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 in late 1979.

Main Variants:

• A3J-1 (A-5A): The initial production version, this was a carrier-based heavy attack aircraft intended for strategic nuclear strike missions.

• A3J-2 (A-5B): An improved bomber model, it featured increased maximum weight and redesigned fuselage to accommodate additional fuel, as well as redesigned wings with enlarged trailing-edge flaps and fully-blown flaps.

• XA3J-3P: Five A3J-2 aircraft completed without reconnaissance systems, and assigned to pilot familiarization.

• A3J-3P (RA-5C): The primary reconnaissance variant, it was equipped with a multi-sensor reconnaissance pack, side-looking airborne radar, infrared line scanner, and camera packs.

• RA-5C: A reconnaissance variant with slightly greater wing area, a long canoe-shaped fairing under the fuselage for a multi-sensor reconnaissance pack, and later-build models had more powerful J79-10 engines.

Technical specifications

Current operating countries

No country is operating the A-5 Vigilante in 2025.

All operators

United States

Armament

Bombs payload:

• Thermonuclear B28 (脡U : Mk 28)
• Thermonuclear B43 Mod 1
• Nuclear California R.L. Mark 27
• Low-Drag Mk 83
• Low-Drag Mk 84

Photo of A-5 Vigilante

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