RAF other ranks

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 term used in the Royal Air Force (RAF) to refer to all ranks below commissioned officer level is other ranks (ORs). It includes warrant officers (WOs), non-commissioned officers (NCOs) and airmen.

Upon the formation of the Royal Air Force on 1 April 1918, rank titles and badges for ORs were adopted from the British Army, specifically the Royal Flying Corps (RFC). The RFC ranks of Flight Sergeant (equivalent to Staff Sergeant), Sergeant, Corporal and Air Mechanic were directly adopted. The RFC's four-bladed propeller trade classification badge above the Sergeants' and Flight Sergeants' chevrons was dropped.

To distinguish them from Army personnel, RAF personnel wore the RAF Eagle on a rectangular patch below the shoulder seam on the sleeve. The RAF Eagle is depicted with its beak turned to the rear rather than the front. RAF NCOs were fond of saying that represented that their eyes were everywhere.

The trade classification of Leading Aircraftman was created on 5th April 1918 to fill a void in the Service ranks. It was granted the double-bladed propeller rank insignia of the RFC Air Mechanic 1st Class and was equivalent in rank and authority to the Army appointment of Lance-Corporal. On 1 January 1919 the rank of Aircraftman replaced the ranks of Private, Air Mechanic, and Clerk. Aircraftmen were nicknamed "Erks" (a corruption of the word 'Aircraft') by the senior ranks, which was preferred to 'other ranks' or 'troops'.

The rank of Master Clerk was originally equivalent to Sergeant Major 1st Class. On 28 November 1918, the new rank of Chief Master Clerk was made equivalent to the rank of Sergeant Major 1st Class, and the old rank of Master Clerk was made equivalent to the rank of Sergeant Major 2nd Class.

The original RAF ranks are vertically listed by seniority; the Technical ranks had precedence over the Administrative ranks, which in turn had precedence over the Service ranks. This was meant to keep non-technical NCOs from interfering with the efforts of technical and administrative NCOs. This was abolished in January 1919 and a streamlined single-column rank system was devised.

...
Wikipedia