Flight lieutenant is a junior commissioned rank in air forces that use the Royal Air Force (RAF) system of ranks, especially in Commonwealth countries. It has a NATO rank code of OF-2. Flight lieutenant is abbreviated as Flt Lt in the Indian Air Force (IAF) and RAF, and as FLTLT in the Pakistan Air Force (PAF), Royal Australian Air Force (RAAF) and Royal New Zealand Air Force (RNZAF) and has sometimes also been abbreviated as F/L in many services; it has never been correctly abbreviated as "lieutenant". A flight lieutenant ranks above flying officer and below a squadron leader and is sometimes used as an English language translation of a similar rank in non-English-speaking countries.
|Service branch||Air forces|
|Abbreviation||Flt Lt / FLTLT|
|NATO rank code||OF-2|
|Formation||1 August 1919 (RAF)|
|Next higher rank||Squadron leader|
|Next lower rank||Flying officer|
|History||Royal Naval Air Service|
The rank originated in the Royal Naval Air Service (RNAS) in 1914. It fell into abeyance when the RNAS merged with the Royal Flying Corps during the First World War but was revived in 1919 in the post-war RAF.
An RAF flight lieutenant is the equivalent of a lieutenant in the Royal Navy and a captain in the British Army and Royal Marines. The equivalent rank in the former Women's Auxiliary Air Force (WAAF), Women's Royal Air Force (WRAF) and Princess Mary's Royal Air Force Nursing Service (PMRAFNS) (until 1980) was flight officer.