Cat "C" Airfields
From an Operations Manual:
These are airfields presenting difficult approach patterns, pecular weather conditions or requiring special knowledge of terrain, airfield or terminal area procedures.
Operation into a category "C " airfield requires a flight into and out of the airfield supervised by a qualified Captain.
In the event of the airfield being categorised as category "C" and there being no Company pilot authorised to operate to that airfield then the flight will be operated either by the Chief Pilot or a Commander designated by him and possessing the necessary experience and ability to operate to that airfield, it being the responsibilty of the Chief Pilot to ensure that such training as he considers necessary is carried out by means of briefing, films or simulated training to ensure the safety of the Flight.
Hope this helps
Tmb