Squadron leader Squadron leader Squadron leader (Sqn Ldr in the RAF ; SQNLDR in the RAAF and RNZAF; formerly sometimes S/L in all services) 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. An air force squadron leader ranks above flight lieutenant and immediately below wing commander and it is the most junior of the senior officer ranks. The air force rank of squadron leader has a
Group captain which have a non-English air force-specific rank structure. It is usually abbreviated Gp Capt. In some air forces (such as the RAF, IAF and PAF), is used while in others (such as the RAAF and RNZAF) and sometimes, especially in historical contexts, as G/C. The rank of group captain is not correctly abbreviated as "captain". On 1 April 1918, the newly created RAF adopted its officer rank titles from the British Army, with Royal Naval Air Service captains and Royal Flying Corps colonels becoming colonels in the RAF. In response to the proposal that the RAF should use its own