Thankyou again Scott,
I have read again the sections that seem most relevant, and still have a few questions...
AIM says Class E airspace extends upward from a specified level where "Federal airway system is inadequate". Is this the step from 1200agl to 14,500amsl? Where is this step located? Is it determined by radio or radar coverage, or other factors?
The descriptions and diagram seems to indicate Class B, C & D airspace extend up to 10,000amsl, 4,000agl & 2,500agl respectively, with
Class E covering the gap up to Class A. Is that the way it is? What happens with such airspace under Class E with a base of 14,500amsl?
ICAO Annexe 11 says at the vertical boundary between 2 airspaces you provide the service applicable to the least restrictive, but 18,500amsl is shown as the boundary between Class E & A, but within Class A! Is this how it is?
Please forgive the detailed questions, I hope they have nice donuts at the meetings... <img src="smile.gif" border="0">