"JGalban via AviationKB.com" u32749@uwe wrote in message
news:7230b56508d63@uwe...

As far as I can tell, there's no standard size for a class D circle. They
define the radius when the airspace is established. If you take a look
at
a sectional of the airports around Phoenix, you'll see that most are 4NM,
but
some are larger and some are smaller. Williams Gateway (IWA) is larger
than
average, and on the west side, both Glendale (GEU) and Goodyear (GYR) are
much smaller than average.


The standard is 3.5 NM plus the distance from the Airport Reference Point to
the end of the outermost runway, rounded up to the next tenth of a mile.
The objective is to maintain departure aircraft within controlled airspace
at a climb fradient of 200' per nautical mile. In cases of rising terrain
the surface area will be a greater.