Class D / Class C precedence

Roy Smith wrote:

"Andrew Sarangan" wrote:

This is described in AIM chapter 3. The rules for the more restrictive
airspace will apply when there is an overlap.


That's an odd way to say it. Consider VFR minimums in overlapping Class D
& B airspace (a pretty common occurance for satellite towered airports
under the shelf of a Class B). The Class D rules say "1000 feet above, 500
feet below, 2000 feet laterally" for cloud clearance. The Class B rules
say "clear of clouds". The D rule is more restrictive, but the B rule is
what's in effect.

You can only be in one airspace at a time. At TTD notice the class D
circle isn't a full cirlce. It gets cut off where the class C goes to
the ground. You can really see this at the airport just northwest of
PDX. In the areas depicted that airspace is class D up to the altitude
given, not a mix of class C and D. You don't get to pick a set of cloud
clearance rules to suit your needs.