RAF officer

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

The officer ranks of the Royal Air Force, as they are today, were introduced in 1919. Prior to that Army ranks were used.

Lieutenant General David Henderson originally proposed that Royal Air Force officers use a combination of British Army and Royal Navy ranks. However, the War Office argued that the RAF should have its own ranks and the Admiralty opposed any use of their rank titles.

On 1 April 1918, Air Force Memorandum 2 specified rank insignia for the newly established independent force. Rank was to be worn on the jacket cuff and was derived from the Royal Navy's rings, each equivalent rank having the same number of rings. However, second lieutenants (now pilot officers) displayed a crowned eagle only and the Navy's loop was not used for any rank. Depending on the uniform, either gold or pale blue on grey braid was worn.

In August 1918, Air Ministry Weekly Order 617 added a single band of 1/4 inch braid below the second lieutenant's eagle and all other officer ranks also received a crowned eagle above their braid.

In 1919 the colour of the rank braid was changed to black with a central pale blue stripe. However, on RAF mess dress rank continued to be displayed in gold.

The ranks worn on the sleeve are common to all RAF uniform variants incorporating the Jacket. The centre of the rank (measured from the bottom of the lowest braid to the top of the highest) should be 3 3/4" (9.5 cm) from the cuff and each row of braiding should have a space of 1/8" (3mm) from other rows. The thinnest braid, as found on the pilot officer's rank (and in the middle of the squadron leader's rank), is 1/4" (6mm); the Flying Officer's braid common to all the ranks except air commodore and pilot officer, is 1/2" (14mm), and the thickest braid, as found on all air officer ranks, is 2" (51mm).

Distinctive shoulder boards (as shown) are worn by Marshals of the Royal Air Force.

Officers entitled to wear aiguillettes and/or the Royal Cypher, AVMs and above, the Director of Nursing Services, and those officers assigned to certain 1-Star posts, wear plain blue shoulder boards when in No 1 Service Dress.

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Wikipedia