Re: Channels and Frequencies
1, I was under the impression that 8.33 kHz spacing was only in use over FL195, therefore it's only really controllers and professional pilots who use it. Maybe I'm out of date? Either way, I can't imagine pilots getting any additional training.
2, I suppose if that's what quantitative studies say, than that's the way it must be. Sounds rather odd to my ear though, and not necessarily any more clearer - less concise and they way the French pronounce "425", it sounds more like "forty-five".