Why did the Vulcan switch from high-altitude bombing to low-level flying?

The Vulcan had been designed to bomb from high altitude, relying on speed and height to avoid interception, since it carried no defensive armament. By the late 1950s and early 1960s, improving Soviet air defences meant that protection was no longer enough.

The cancellation of the US Skybolt missile in 1962 left the RAF with the Blue Steel as its stand-off weapon. To bridge the gap until the Royal Navy took over the deterrent role with its Polaris missile submarines, the Vulcans adopted a new mission profile: fly high during the clear transit, descend to low level on the approach to evade enemy defences, and release a parachute-retarded bomb. The low-level tactic was introduced in the mid-1960s.

Low flying put strain on the structure. The B.2s received wing reinforcements to achieve the required fatigue life, along with terrain-following radar, new navigation equipment, improved countermeasures, and a common weapon, the WE.177. The unreinforced B.1As had all been retired by 1968.

Not everyone was convinced. Air Vice-Marshal Ron Dick, a former Vulcan pilot, even doubted whether the aircraft would have been effective flying low level in a war against the Soviet Union. When the Polaris submarines entered service and Blue Steel was withdrawn in 1970, the Vulcan continued carrying the WE.177B in a tactical nuclear role as part of Britain's contribution to NATO.