The A-5 Vigilante was as ambitious as it was advanced. The company that designed the Vigilante, North American Aviation, sought to harness recent advances in jet engine technology that the 1950s had witnessed to build a very high performance, Mach 2-capable heavy bomber that could operate from the constrained environments typical of naval aircraft carriers.
A-5 Vigilante: Origin Story
After pitching the idea to the U.S. Navy, and subsequently incorporating several changes to the design, North American Aviation started work on the proposed bomber. The final product, the A-5 Vigilante, was very advanced for the time.
The large bomber made extensive use of a novel aluminum-lithium alloy for the Vigilante’s wing skin that was significantly lighter than aerospace aluminum alone. Other parts of the airframe used expensive but robust and lightweight titanium components.
The Vigilante was one of the first bombers to use electronic fly-by-wire flight controls as well as a computerized head-up type pilot display and an onboard digital computer to aid the pilot in operating the extensive onboard electronics. In recognition of both of the Vigilante’s large footprint and the limited space available on Navy aircraft carriers, the Vigilante’s wingtips, nose cone, and vertical stabilizer could fold inward, making the large jet bomber somewhat more compact.
As the Vigilante was primarily a heavy bomber, it was equipped to deliver the nuclear payload, though in an unusual configuration. The Vigilante’s two, relatively widely spaced engines allowed the large bomber to carry additional fuel as well as a Mk 28 nuclear bomb in a central, cylindrically-shaped weapons bay between them. En route to a target, the Vigilante would use the fuel stored in the cylinder bay, which would be jettisoned along with the Mk 28 bomb when at target. Through an innovative feature that helped extend the Vigilante’s range, the setup was less than reliable in practice.
Thanks to the Vigilante’s very clean lines and powerful engines, it could easily achieve Mach 2 speeds, though the A-5’s introduction coincided with a strategic shift in Navy planning. Rather than relying on manned bombers for nuclear weapon delivery, the Navy began to emphasize submarine-launched ballistic missiles instead. The A-5’s role subsequently changed from high-speed heavy bombing to high-speed after-action reconnaissance, a role in which excelled during the Vietnam War.
Although the A-5 performed relatively well, post-Vietnam budget cuts, the bomber’s high cost, as well as the introduction and prioritization of naval fighters like the F-14 Tomcat sealed the Vigilante’s fate and ultimately giving it a relatively short service life. Still, the Vigilante was an innovative heavy bomber that just came at the wrong time for the U.S. Navy.
Caleb Larson is a Defense Writer based in Europe. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture.