Squadron Leader Squadron Leader is a commissioned rank in the Royal Air Force and the air forces of many countries which have historical British influence . It is also sometimes used as the English translation of an equivalent rank in countries which have a non - English air force - specific rank structure . In these cases a Squadron Leader ranks above Flight Lieutenant and immediately below Wing Commander . Several abbreviations are used , including Sqn Ldr , Sqn . Ldr . , SQNLDR and S / L in the various air forces of the world . It has a NATO ranking code of OF - 3 , equivalent to a Lieutenant - Commander in the Royal Navy or a Major in the British Army or the Royal Marines . The equivalent rank in the Women ' s Auxiliary Air Force ( WAAF ) , Women ' s Royal Air Force ( WRAF ) ( until 1968 ) and Princess Mary ' s Royal Air Force Nursing Service ( PMRAFNS ) ( until 1980 ) was Squadron Officer . Origins . The rank originated in the British Royal Air Force and was adopted by several other air forces which use , or used , the RAF rank system . On 1 April 1918 , the newly created RAF adopted its officer rank titles from the British Army , with Royal Naval Air Service Lieutenant - Commanders and Royal Flying Corps Majors becoming Majors in the RAF . In response to the proposal that the RAF should use its own rank titles , it was suggested that the RAF might use the Royal Navy ' s officer ranks , with the word " Air " inserted before the naval rank title . For example , the rank that later became Squadron Leader would have been Air Lieutenant - Commander . However , the Admiralty objected to this modification of their rank titles . The rank title Squadron Leader was chosen as Squadron s were typically led by RAF Majors and the term Squadron Commander had been used in the Royal Naval Air Service . The rank of Squadron Leader has been used continuously since 1 August 1919 . RAF usage . Before the Second World War , a Squadron Leader commanded a squadron of aircraft . Today , however , 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 Squadron s . The rank squadron leader is the first senior officer rank within the RAF . Insignia and command flag . 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 ranking officers that may fly a command flag . The flag may be depicted on the officer ' s aircraft or , should the squadron leader be in command , the flag may be flown from a flagpole or displayed on an official car as a car flag . If the Squadron Leader is in command of a numbered squadron , then the number of the squadron would also be shown on the flag . Other air forces . The rank of Squadron Leader is also used in a number of the air forces in the Commonwealth , including the Bangladesh Air Force , Ghana Air Force , Indian Air Force ( IAF ) , Sri Lanka Air Force ( SLAF ) , Pakistan Air Force ( PAF ) , Royal Australian Air Force ( RAAF ) and Royal New Zealand Air Force ( RNZAF ) . It is also used in the Egyptian Air Force , Hellenic Air Force , Royal Air Force of Oman and the Royal Thai Air Force . The Royal Canadian Air Force ( RCAF ) used the rank until the unification of the Canadian Forces in 1968 , when army - type rank titles were adopted . Canadian squadron leaders were retitled as major s . In official French Canadian usage , a squadron leader ' s rank title was " commandant d ' aviation " . The Chilean Air Force equivalent rank , in Chilean Spanish , is " Comandante de Escuadrilla " or Squadron Commander . Land forces . In the British Household Cavalry and Royal Armoured Corps , " Squadron Leader " is the title ( but not the rank ) often given to the commander of a squadron ( company ) of armoured fighting vehicle s . The squadron leader is usually a Major , although in the Second World War the post was often held by a Captain . Fiction . The rank has been borrowed in science fiction including the " Star Wars " films and its extended universe of literature and comics , though ( at least in the " Star Wars " franchise ) more often as the title and \ or callsign of the leader of a starfighter squadron , irrespective of rank ( similar to the aforementioned RAC usage ; see ) , and usually with the word " Squadron " replaced by the name of the squadron , e . g . for the commander of Red Squadron , and infrequently as an actual rank . For the most part , this is just another example of common depiction of starfighter forces in most works featuring such craft as closely paralleling contemporary ( at the time the work in question was produced ) real - world air forces in almost all aspects .