The jargon here in the US is something that sometimes annoys me and lacks discipline, but I do have to say that some of the Americanisms are actually better. One very good example are altitudes above 4 digits: "Thirteen thousand five hundred feet" is much more legible and understandable than "One three thousand five hundred". The human mind doesn't compute additive instructions as well as compound ones.
Very often you hear crews ask for clarification on either new freq or altimeter settings and what alway settles it is when the controller departs ICAO and speaks "plain english". Example:
"Contact SoCal on one two three point seven five".
"What was that frequency again?"
"Twenty three seventy five".
Additive vs compound again. The latter is much clearer to compute in all scenarios. Settles it right away and I've never heard anyone ask for them to repeat such an instruction - ever. If safety and brevity is the objective, then the instruction that is the most understandable is the correct one, ICAO or not.
Last edited by AdamFrisch; 12th Jul 2013 at 09:25.