tubby:
Back in the 1980s ( the last time I remember using it) you used to be able to contact other airfields in the UK by calling them on the ministry line. I was given the impression that this was a network that was independent of the normal public telecoms, and the numbers to dial were much shorter than the BT landline ones. Would anybody be able to tell me more about the system please?
TWA had something like that until sometime in the 1980s. It was called "PLF," which I believe stood for private line fone. It was hot all the time. I believed you dialed a 2 digit code to ring a particular station. Sort of a fancy party line. You'd pick it up and if no one was speaking you would say "line clear?" before you dialed a code. It covered the U.S. domestic system.