The Chief of the Air Staff's Warrant Officer (CASWO) is the senior warrant officer (WO), and therefore the most senior non-commissioned position in the Royal Air Force (RAF). The person holding this military appointment advises the Chief of the Air Staff (CAS) on matters concerning airmen and airwoman of the RAF. The post was created in 1996.
List of Chief of the Air Staff's Warrant Officers
The Royal Navy equivalent is the Warrant Officer of the Naval Service (WONS), and in the Royal Marines the Corps Regimental Sergeant Major. The British Army's recent equivalent is the Army Sergeant Major.
References
Chief of the Air Staff's Warrant Officer Wikipedia(Text) CC BY-SA