Dan wrote: Thank you Bob, that clears that one up for me. Appreciate your help.
To my understanding yes a CTAF is a radio frequency and not an airspace classification as per Class C or Class D etc . However , I do think of “CTAF AREA “( or MTAF AREA) - surrounding a specific airfield using that designated frequency and so actually as a volume of space - in which the CTAF designated to that area needs to be used for radio calls for plane separation, position awareness to other pilots in the same area ect. . I have dated books. advising a CTAF “area” is 5nm radius by 3000 ft AAL and a MTAF ( Mandatory Traffic Advisory Freqyency) area is 15nm radius by 5000ft above arerodrome level (AAL). Are these dimensions still valid ? Further, am I right in thinking if I’m not in that space then I do not have to listen in or broadcast on that frequency eg as in the case of flying over an airfield on route to elsewhere?