From: dst+@cs.cmu.edu (Dave Touretzky)
Newsgroups: rec.aviation
Subject: teaching alphabet airspace
Date: 25 Aug 92 23:13:47 GMT
Distribution: usa
Organization: School of Computer Science, Carnegie Mellon

The problem with all these articles on alphabet airspace is that they're too
abstract.  They give the definitions of the various airspace types, but
don't do much to help the reader relate this info to his/her own situation.
To try to remedy this, I wrote an article for our airport association
newsletter in which I showed how the new classification scheme would affect
our own *local* airspace.

The article is reproduced below.  Feel free to adapt it to your own needs --
with appropriate credit to the originator, please.

................................................................

	Alphabet Airspace and You

	    by Dave Touretzky

 In the past few months, virtually every aviation publication has run
articles on the FAA's airspace reclassification plan.  Although the plan
isn't slated to go into effect until September, 1993, you may have already
noticed that TRSAs are now depicted in black on sectional charts.
Additional charting changes will become evident in October of this year,
when new sectionals are released that show both current and planned
terminology for several types of airspace.

The new scheme will bring the US airspace structure into closer agreement
with ICAO standards now in use throughout the world.  Due to its use of the
letters A-G in place of acronyms like TCA and ARSA, the proposal is
frequently referred to as ``alphabet airspace,'' but the changes involve
more than a simple renaming.  The dimensions of some types of airspace will
change, e.g., airport traffic areas will shrink in height from 3000 to 2500
feet AGL.  Charting conventions and operational procedures will also change
somewhat.  For a preview of what the new charts will look like, see the
April, 1992 issue of Flight Instructors' Safety Report, available from the
AOPA Air Safety Foundation.  A detailed summary of the operational
considerations for each class of airspace is available for free from the
Pittsburgh FSDO, located on the second floor of the terminal building.

Let's look at how these changes will affect us at Allegheny County.  First
of all, the Positive Control Area, which begins at 18,000 feet MSL, will
become Class A Airspace.  The Pittsburgh TCA will become Class B Airspace,
and its VFR weather minima will be relaxed to ``3 miles, clear of clouds,''
rather than the more stringent cloud clearance requirements that apply
today (500 feet below, 1000 feet above, and 2000 feet horizontally.)  This
change is possible because all flight within Class B Airspace will be
controlled and provided radar separation.  In lower airspace categories the
normal VFR cloud clearance requirements still apply.

The Akron-Canton ARSA will be our closest example of Class C Airspace.
TRSAs such as Youngstown's are not part of the ICAO airspace structure,
although they will continue to exist in the US for the time being.

Allegheny County's airport traffic area and associated control zone will
become Class D Airspace.  These two functions are merged under the new
plan.  You'll also be able to go around the pattern at AGC a little faster
than before: the speed limit for all aircraft within 4 nautical miles of
the primary airport for Class B, C, or D Airspace will be 200 knots.  The
200 knot limit also applies underneath the shelves and within any VFR
corridors associated with Class B Airspace.  Elsewhere the 250 knot limit
applies below 10,000 feet.

Class E airspace covers general controlled airspace (transition areas,
victor airways), and also control zones not associated with an operating
control tower.  So Dubois and Franklin will be located in Class E Airspace
because they have control zones.  Latrobe's airspace will be Class D most
of the time, but will revert to Class E when the tower closes for the
night.

Uncontrolled airspace is Class G.  If you flew from, say, Rostraver to
Clarion at less than 700 feet AGL, you'd be in Class G airspace all the
way.  (Kids, don't try this at home.)  There is no Class F airspace in the
US.  It's used for regions where ATC provides IFR separation service only
``so far as practical.''
Newsgroups: rec.aviation