Squadron leader a flying squadron is usually commanded by a wing commander, with each of the two flights under a squadron leader. However, ground-operating squadrons which are sub-divisions of a wing are ordinarily commanded by a squadron leader. This includes squadrons of the RAF Regiment and University Air Squadrons. The rank insignia consists of a thin blue band on a slightly wider black band between two narrow blue bands on slightly wider black bands. This is worn on both the lower sleeves of the tunic or on the shoulders of the flying suit or the casual uniform. Squadron leaders are the lowest
Squadron leader RAF used major as the equivalent rank to squadron leader. Royal Naval Air Service lieutenant-commanders and Royal Flying Corps majors on 31 March 1918 became RAF majors on 1 April 1918. On 31 August 1919, the RAF rank of major was superseded by squadron leader which has remained in continuous usage ever since. Promotion to squadron leader is strictly on merit, and requires the individual to be appointed to a Career Commission, which will see them remain in the RAF until retirement or voluntary resignation. Before the Second World War, a squadron leader commanded a squadron of aircraft. Today, however,