Commander Air Force's mid-rank officers' ranks are modelled on those of the Royal Navy, the term wing commander is used as a rank, and this is the equivalent of a lieutenant colonel in the army or a commander in the navy. The rank of wing commander is above that of squadron leader and below that of group captain. In the former Royal Naval Air Service, which was merged with the Royal Flying Corps to form the Royal Air Force in 1918, the pilots held appointments as well as their normal ranks in the Royal Navy, and they wore insignia appropriate to
Squadron leader in Chilean Spanish, is "comandante de escuadrilla" or squadron commander. 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 vehicles. The squadron leader is usually a major, although in the Second World War the post was often held by a captain. 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