Group captain

Common military ranks in English
Navies	Armies	Air forces
Commissioned and Non-commissioned officers
Admiral of the fleet	Marshal or Field marshal	Marshal of the air force
Admiral	General	Air chief marshal
Vice admiral	Lieutenant general	Air marshal
Rear admiral	Major general	Air vice-marshal
Commodore	Brigadier or Brigadier general	Air commodore
Captain	Colonel	Group captain
Commander	Lieutenant colonel	Wing commander
Lieutenant commander	Major or Commandant	Squadron leader
Lieutenant	Captain	Flight lieutenant
Sub-lieutenant	Lieutenant or First lieutenant	Flying officer
Ensign	Second lieutenant	Pilot officer
Midshipman	Officer cadet	Flight cadet
Enlisted grades
Warrant officer or Chief petty officer	Warrant officer or Sergeant major	Warrant officer
Petty officer	Sergeant	Sergeant
Leading seaman	Corporal	Corporal
Seaman	Private	Aircraftman

Group captain (Gp Capt in the RAF, IAF and PAF, GPCAPT in the RNZAF and RAAF; formerly sometimes G/C in all services) is a senior commissioned rank which originated in and continues to be used by the Royal Air Force. The rank is also used by the air forces of many countries which have historical British influence and it is sometimes used as the English translation of an equivalent rank in countries which have a non-English air force-specific rank structure. It ranks above wing commander and immediately below air commodore. The name of the rank is the complete phrase, and is never shortened to "captain".

It has a NATO ranking code of OF-5, and is equivalent to a captain in the Royal Navy or a colonel in the British Army or the Royal Marines. Group captain is the rank usually held by the station commander of a large RAF station.

The equivalent rank in the Women's Auxiliary Air Force, Women's Auxiliary Australian Air Force, Women's Royal Air Force (until 1968) and Princess Mary's Royal Air Force Nursing Service (until 1980) was "group officer". The equivalent rank in the Royal Observer Corps (until 1995) was "observer captain", which had a similar rank insignia.

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 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 group captain would have been "air captain". Although the Admiralty objected to this simple modification of their rank titles, it was agreed that the RAF might base many of its officer rank titles on naval officer ranks with differing pre-modifying terms. It was also suggested that RAF colonels might be entitled "bannerets" or "leaders". However, the rank title based on the Navy rank was preferred and as RAF colonels typically commanded groups the rank title group captain was chosen. The rank of group captain has been used continuously since 1 August 1919.

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