The Vickers-Armstrongs Valiant was a British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 four-jet bomber

Bomber

A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...

, once part of the Royal Air Force

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

's V bomber

V bomber

The term V bomber was used for the Royal Air Force aircraft during the 1950s and 1960s that comprised the United Kingdom's strategic nuclear strike force known officially as the V-force or Bomber Command Main Force...

 nuclear force in the 1950s and 1960s. The Valiant was originally developed for use as high-level strategic bomber

Strategic bomber

A strategic bomber is a heavy bomber aircraft designed to drop large amounts of ordnance onto a distant target for the purposes of debilitating an enemy's capacity to wage war. Unlike tactical bombers, which are used in the battle zone to attack troops and military equipment, strategic bombers are...

, but its role, like other V bombers, was changed to low-level attacks.

Low-level flying brought a number of serious problems as the Valiant's wing spar attachment castings showed premature fatiguing and inter-crystalline corrosion traced to the use of an inappropriate type of aluminium alloy.