The Tactical Supply Wing (TSW), a/k/a "Tiswas", was formed at RAF Stafford in late 1970. Tiswas was sent on its first operational deployment to Northern Ireland in 1971.
Tiswas' primary role is supporting the deployment of helicopter operations. It specialises in providing rotors-turning refueling to NATO helicopters; this is done from the back of a transport aircraft, such as a C130J/K. This is often done on provisional airfields or fields in which their plane has landed.
The original article can be found at Tactical Supply Wing RAF and the edit history here.