A-5 Vigillante

Fact For 14/6/2021



The North American A-5 Vigilante was an American carrier-based supersonic bomber designed and built by North American Aviation (NAA) for the United States Navy. Prior to 1962 unification of Navy and Air Force designations, it was designated the A3J Vigilante. The Vigilante was introduced by the US Navy during June 1961; it succeeded the Douglas A-3 Skywarrior as the Navy's primary nuclear strike aircraft, but its service in this capacity was relatively brief due to the deemphasising of manned bombers in the US' nuclear strategy. A far larger quantity of the RA-5C tactical strike reconnaissance variant were also procured by the service, which saw extensive service during the Vietnam War. It also established several world records in both long-distance speed and altitude categories


During the mid-1950s, the notion of a nuclear-armed aircraft capable of speeds of up to Mach 2 was considered to be quite ambitious, and only more so for that same aircraft to be operable under the unavoidable constraints imposed by aircraft carrier operations. In terms of its basic configuration, the conceptual aircraft featured twin-engines and high-mounted wing, akin to the XA2J, but differed substantially by being highly swept and adopting jet propulsion. 
This proposal, which was referred to the North American General Purpose Attack Weapon (NAGPAW) concept, was promptly evaluated by the United States Navy. The service produced numerous challenging demands, including the somewhat contradictory necessity of both a high speed of Mach 2 and the ability to perform carrier takeoffs at maximum weight under zero wind conditions. Compton's team were able to reconcile these performance requirements into the design
On 31 August 1958, one of these prototypes performed the type's maiden flight from Columbus, Ohio. By this point, the role envisioned for the aircraft within the US Navy had shifted somewhat. According to Gunston and Gilchrist, officials had viewed the aircraft through the lens of the Korean War and placed a high value on performing low-level conventionally-armed attack missions, but had subsequently shifted towards viewing the in-development bomber as a successor to the Douglas A-3 Skywarrior in the strategic nuclear attack role instead. Thus, the design team implemented a somewhat unorthodox bomb bay as to accommodate the stowage of a nuclear weapon, which was also designed to accommodate both fuel tanks and reconnaissance payloads

Design and Features

 It was furnished with a high-mounted swept wing with a boundary-layer control system (blown flaps) to improve low-speed lift. It lacked ailerons; instead, roll control was provided by spoilers in conjunction with differential deflection of the all-moving tail surfaces, which were paired with a relatively large all-moving single vertical stabilizer. The use of aluminum-lithium alloy for wing skins and titanium for critical structures was also unusual for the era; other exotic materials included the use of a gold coating to reflect heat in key areas such as the bomb bay. The wings, vertical stabilizer and the nose radome all folded to enable easier stowage onboard aircraft carriers. Propulsion was via a pair of widely-spaced General Electric J79 turbojet engines . The electronics of the Vigilante were relatively advanced and complex at the time of its entry to service. It incorporated one of the first "fly-by-wire" systems on an operational aircraft, along with mechanical/hydraulic backup. Vigilante's main armament was carried in an unusual "linear bomb bay" between the engines in the rear fuselage, which allowed the bomb to be dropped 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 the 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 (15 m) per second (30 knots) relative to the aircraft. It then followed a ballistic path. 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 to accommodate fuel. On three occasions, the shock of the catapult launch caused the fuel cans to eject onto the deck; this phenomenon reportedly resulted in one aircraft loss . it had AN/ASB-12 Bombing & Navigation Radar and had various electronics including radar jammers , IR ECM receivers , RWRs , electronic reconaissance sytem . and IR reconaissance system

source - Wikipedia