Before my QWI days the qualification had been developed from the merging of several streams. I think in the RN it was the AWI (?) and in the RAF the FAI (?). Something like this.
The RN (FAA) certainly used to have the letters AWI (my father was one back in the day). The lack of current fixed wing may have changed that..........I'm sure somebody with more knowedge will come back with an answer.
TN.
TN,
the RN AWI qual was the Air Warfare Instructor.
The RAF had, I think, the FAI - Fighter Attack Instructor.
I think the FAI qual was run by a TWU, and did not initially extend to individual aircraft types run by an OCU - I may be wrong.
Anyway, I think CTTO (Johnny Walker maybe?) developed this into individual type qualifications then run by the OCUs, which became the QWI qual.
The QWI concept is used by different air forces around the world. USAF has FWIC. RAAF has FCI.