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.

Newps writes:

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.

Yeah, but look at the altitudes. The top of the Class D appears to be
_above_ the floor of the Class C that it overlaps.

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Roy Smith writes:

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.

Zero clouds is less restrictive than clouds a few thousand feet away?

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Mxsmanic wrote:
Roy Smith writes:

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.

Zero clouds is less restrictive than clouds a few thousand feet away?

Not "zero clouds", but "clear of clouds". Having to stay away from a
cloud by only an inch is much less restrictive than having to stay
hundreds of feet away.

Kev

Andrew Sarangan writes:

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.

They aren't airspace classes though. Class B and Class C are both
airspace classes; logically they cannot occupy the same space at the
same time.

Restricted and other special airspace is an additional qualifier that
supplements the existing airspace class, so they can coexist.

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In article ,
says...


If Class C overlaps Class D (see Portland Troutdale airport), which
airspace takes precedence?

You must, at all costs, avoid the spot where they overlap.
The superimposition of thes two types of air produces standing lenticular
clouds, which can produce very dangerous turbulence.

I don't know if anyone else caught that, but it was very funny. Thanks!

Dennis



"Greg Farris" wrote in message
...
In article ,
says...


If Class C overlaps Class D (see Portland Troutdale airport), which
airspace takes precedence?

You must, at all costs, avoid the spot where they overlap.
The superimposition of thes two types of air produces standing lenticular
clouds, which can produce very dangerous turbulence.

"Dennis" wrote in message
. ..
I don't know if anyone else caught that, but it was very funny. Thanks!

I second that chuckle! :-)
--
Jim in NC

"Morgans" wrote in message
...

"Dennis" wrote in message
. ..
I don't know if anyone else caught that, but it was very funny. Thanks!

I second that chuckle! :-)
--
Jim in NC
Jim (or any other USA contributors)
Slightly OT I know but can someone advise me (since we are talking
airspace) - are transponders mandatory to carry and use in Class E airspace
in the US?
cheers
Brian

SR20GOER wrote:


Slightly OT I know but can someone advise me (since we are talking
airspace) - are transponders mandatory to carry and use in Class E airspace
in the US?


No.