The Special Air Service (SAS) is the principal special forces organisation of the British Army. A small and secretive institution, it attracts a disproportionate amount of media coverage. The SAS was formed in 1941 to conduct raids behind German lines in North Africa, and today serves as a model for similar units fielded by other countries.[citation needed]
The SAS forms part of the United Kingdom Special Forces, alongside the Special Boat Service (SBS), Special Reconnaissance Regiment (SRR), and Special Forces Support Group (SFSG). The SAS is widely regarded as one of the finest and best-trained special forces units in the world.
http://en.wikipedia.org/wiki/Special_Air_Service
I believe the U.S. Delta Force was established as an American eqivalent by an U.S. special forces operative who had served with the SAS.
"From its beginnings, Delta was heavily influenced by the British SAS, a philosophical result of Col. Beckwith’s year-long (1962-1963) exchange tour with that unit. Accordingly, it is today organized into three operating squadrons, all of which (A, B, and C) are subdivided into small groups known as troops. It is rumored that each troop, as the case with the SAS, specializes in HALO, SCUBA, or other skill groups"
http://www.specialoperations.com/Army/Delta_Force/unit_profile.htm
Thank you.
There was no distinction of "airborne" rangers at that time, as all rangers were parachute qualified.. and trained to fight behind enemy lines, assault unassailable positions, and generally do the impossible whenever ordered to do so..
Anyone that qualified to become SAS or Ranger back then was indeed a "special force"..