Description and use of the flag

The British Royal Air Force Ensign is in light "Air Force" blue with the Union Jack in the canton and the Royal Air Force roundel, concentric rings of red-white-blue (from the inside out) in the middle of the fly.
Roy Stilling, 18 December 1995

Before 1918 the Royal Naval Air Service used the White Ensign and I presume that the Royal Flying Corps used whatever flags were appropriate for a corps of the army, perhaps just the Union Jack? An interim flag was produced to represent the Royal Air Force at the armistice celebrations; a 'white ensign' with an overall dark blue St George's Cross, the Royal Air Force eagle in the centre of the cross, and a royal crown above it on the vertical arm of the cross. Rather more attractive than the roundel ensign, but not to the liking of the Admiralty who thought it looked too much like a naval flag. Between the armistice and 26 July 1920 when the present ensign was approved, the Royal Air Force was supposed to fly the Union Jack, but some former Royal Naval Air Service units flew the White Ensign, or the white ensign with a blue St George's Cross, but without the eagle and crown.

During World War II there was a Royal Air Force ensign with a black, yellow and red roundel - the ensign of the Belgian Section of the Royal Air Force.

David Prothero, 11 November 1998

Above the main entrance of the Ministry of Defence building in Whitehall are three flagpoles with the Royal Navy's White Ensign, the British Army flag, and the Royal Air Force ensign flying in that order (from the observer's left to right).
Joseph McMillan, 23 September

The Royal Air Force Ensign was approved without difference as the ensign of the Royal Australian Air Force on 24 July 1922 (AIR 2/211), and was not changed until 1949; but Canada and New Zealand had their own Air Force ensigns during WW2. 
The Royal Canadian Air Force was granted the right to use the Royal Air Force Ensign on 12 October 1921 (AIR 2/211), but replaced the central red disc with a red maple leaf in March 1940 (AIR 2/6141).
The Royal New Zealand Air Force applied to change its ensign in August 1939. The new ensign was described as, "the Ensign of the Royal Air Force defaced by the addition of the letters N Z superimposed in white upon the red roundel of the ensign" (AIR 30/140).
References are Public Record Office documents at Kew.
David Prothero, 2 June 2002

This flag was introduced in 1918, and was concurrent with the founding of the Royal Air Force as a separate fighting unit.
Christopher Southworth, 4 December 2003

The RAF have always referred to their flag as the RAF Ensign. It may possibly be by analogy with the White Ensign, particularly as the RAF originally wanted to have a White Ensign without the cross as their flag (they also tried a White Ensign with a blue cross, which they referred to as a St. Michael's cross). The Admiralty, on the other hand, stubbornly referred to it as an RAF flag, refusing to admit that the RAF had any right to fly an ensign.

The RAF flag/Ensign was flown by the various launches and tenders that were part of seaplane squadrons in the 1920s and 1930s, and then by the vessels of the Air Sea Rescue Service, formed in 1939. Later renamed the Maritime Section, it was civilianised in 1986. The craft then flew a Blue Ensign, defaced by a badge of an RAF eagle above an anchor, all in yellow. That has since been wound up, and ASR services passed over to RAF helicopter squadrons (plus the RNLI and Coastguard).

It remains open to question whether they actually had permission to fly the RAF Ensign as an ensign, however. The original Order in Council gave permission for the flag to be used whenever and wherever the Air Council saw fit, but the Admiralty did not think that the Order superseded the provisions of the Merchant Shipping Act. In 1947, an RAF vessel was seized at sea by Customs, on the grounds that it was flying an illegal ensign (the RAF one), instead of the Red Ensign. The ASR launches got round the problem by the flying the flag from the mast, and flying nothing at the stern. In any case, as high speed vessels, the stern almost disappeared under the water when travelling at speed, so the ensign might not have properly visible anyway.

Air bases have always been referred to as 'stations', and individually by name with the prefix 'RAF', e.g. RAF Finningley. The service would certainly have inherited a tradition of flying a flag at each station from the Royal Naval Air Service (which went to part form the RAF in 1918).

Sources: PRO ADM 1/19970, 1/21665.

Ian Sumner, 4 December 2003

The RAF flag is definitely an ensign. It's been labelled that way in BR20 for years. In Britain "ensign" is traditionally just another word for "flag", but has come to mean a flag with the national flag in the canton. And it will be called the RAF Ensign in the next edition of BR20 too, along with the rest of the RAF flags.

The official Pantone shade of the RAF Ensign is 549, which looks too dark when printed on paper but works in fabric. The illustrations in the printed BR20 used Pantone 292 as and alternative, but I'm not happy with it and am looking at alternatives, such as a tint of Pantone 549 to simulate the fabric flag. A grey pale blue is a good description.
Graham Bartram, 5 December 2003

The RAF ensign is flown from gaffs. Because of their descent from RNAS stations, RAF stations, like naval shore stations, are pseudo 'ships', flying their ensigns as if from the spankers of sailing ships.
Stephen Fletcher, 12 August 2004