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.

I didn't make this up. It is in AIM 3-1-3.

"a. When overlapping airspace designations apply to the same airspace,
the operating rules associated with the more restrictive airspace
designation apply. "

Then it goes on to clarifiy specific designations. It does say that
class B is more restrictive than the other classes, and class A is the
most restrictive.




An obvious example of this is restricted airspaces. The majority of
R-airspaces overlap with G or E airspaces, but in those instances we
don't question which rules apply.

R is not an "airspace class". There are no VFR minima for R-areas. If I
call up NY Approach, ask to transition R-5206, and receive approval to do
so, the weather minima of the underlying E or G airspace are in effect.


Again, I am quoting from the AIM.

"There are two categories of airspace or airspace areas:

1. Regulatory (Class A, B, C, D and E airspace areas, restricted and
prohibited areas); and

2. Nonregulatory (military operations areas (MOAs), warning areas,
alert areas, and controlled firing areas)."