Using the magenta circles

It is on the IFR charts because -- at least in theory -- the information
helps VFR pilots determine where they can legally scud run and at what
airports they can legally fly a standard 1000-foot pattern on a marginal VFR
day. Whether that is safe or whether VFR pilots actually are aware of or
follow these rules is another matter.

The distinction between a 700-foot transition zone or a 1200-foot transition
zone basically helps VFR pilots to determine if they can fly a standard
800-foot or 1000-foot pattern on a day when there is a 1000-foot ceiling.
The answer is yes for airports with 1200-foot transition zones and no for
airports with 700-foot transition zones.

A related issue has to do with Class E Surface Areas -- generally commuter
or regional airlines are permitted only to fly at airports which have Class
E Surface Areas and thus -- at least in theory -- where it should not be
possible for an IFR airplane to break out of a cloud and find a VFR airplane
1 foot below. This means that on marginal VFR days it is at least
theoretically safer for an IFR pilot to land at an airport with a Class E
Surface Area than with Class G airspace on the surface.

--
Richard Kaplan, CFII

www.flyimc.com

The difference between class E and G airspace is that ATC
cannot control traffic in class G (thus... it's uncontrolled)...
By lowering the floor of the class E (in which ATC can control
aircraft) over small airports, IFR flights can remain under
ATC control to a lower altitude, thus facilitating the IFR
approach process...

The fact that VFR minimums in class G are 1 mile and
clear of clouds is not to encourage VFR pilots to go fly
in that, but to make it legal for instrument pilots to complete
approaches where the visibility minimums are 1 mile in the
class G airspace... Ever wondered why SVFR minimums are
1 mile and clear of clouds... Same reason...


John Price
CFII/AGI/IGI
http://home.att.net/~jm.price


"Ace Pilot" wrote in message
om...
A friend recently asked me to explain the magenta circles seen around
numerous airports on sectionals. It got me to thinking about how
useful they are. Personally, if the weather isn't good enough to fly
VFR in Class E airspace, I'm not going to fly VFR, even if it is legal
in Class G airspace. So, for me, it is pointless knowing where the
boundary is between Class E and Class G airspace.

But I was curious to know if there are pilots that take full advantage
of this distinction. Does anyone actually make use of the Class E/G
boundaries depicted on sectionals? If so, how? I suspect the most
common use is doing T&Gs in the pattern below 700 feet AGL when the
weather is marginal. Other uses?

"john price" wrote in message
...

The fact that VFR minimums in class G are 1 mile and
clear of clouds is not to encourage VFR pilots to go fly
in that, but to make it legal for instrument pilots to complete
approaches where the visibility minimums are 1 mile in the
class G airspace...


VFR minimums have nothing to do with IFR approaches.

"john price" wrote in message
...

The fact that VFR minimums in class G are 1 mile and
clear of clouds is not to encourage VFR pilots to go fly
in that, but to make it legal for instrument pilots to complete
approaches where the visibility minimums are 1 mile in the
class G airspace...

With visibility of 1 mile I would never cancel IFR until I am on the ground.
Thus how would the VFR weather rules affect my flight other than by settting
cloud distance requirements for VFR airplanes in Class E airspace?


--
Richard Kaplan, CFII

www.flyimc.com

"Steven P. McNicoll" wrote in message ink.net...

"Ron Natalie" wrote in message
m...

Those circles aren't to keep VFR pilots safe when the weather is marginal.
They are to lower the floor of controlled airspace for the benefit of IFR
pilots.

This accomplishes two things:
1. Allows ATC to provide control to lower altitudes, primarily
separation from other IFR aircraft.
2. Makes sure any there is sufficient visibility / cloud clearance
for visual separation techniques to be used between any
VFR aircraft that might be present.


Changing weather has no effect on the floor of controlled airspace.


I never said it did.

"Steven P. McNicoll" wrote in message nk.net...

"BTIZ" wrote in message
news:vJqbc.69606$1I5.24219@fed1read01...

But I did not think he said anything about changing the floor of the
airspace for weather, he stated that the lower floor provides transistions
for IFR pilots to get close to the airport, and CLEAR OF VFR traffic in
marginal weather, that should be remaining in Class G and not Class E
where
the approach may dump them off.


He said; "Those circles aren't to keep VFR pilots safe when the weather is
marginal. They are to lower the floor of controlled airspace for the
benefit of IFR pilots."


Correct. The transition area lowers the floor of controlled airspace. I never
said it had anything to do with changing weather conditions. The first sentence
was to refute the hypothesis of the original poster.

"Ron Natalie" wrote in message
m...

I never said it did.


Well, if you didn't, then somebody else is posting here under the name "Ron
Natalie".

"Ron Natalie" wrote in message
m...

Correct. The transition area lowers the floor of controlled airspace.


The floor of controlled airspace is fixed.

"Steven P. McNicoll" wrote in message ink.net...

"Ron Natalie" wrote in message
m...

Correct. The transition area lowers the floor of controlled airspace.


The floor of controlled airspace is fixed.

The transition area floor is LOWER than it would be if there were no transition area.
It's a local dropping of the controlled airspace floor from 1200 (typically) to 700.

Everybody else seems to understand what I'm saying except for you. Stop and try
to think about the real issue rather than trying to generate as much confusion as possible.

(Ace Pilot) wrote in message om...
That was my impression, too, CJ. And I'm in the Midwest where we don't
have to worry about mountains. I just have a hard time picturing
someone following their progress on a sectional flying under a ceiling
of 1,000 feet and dipping below 700 feet AGL everytime they approach
an airport with a magenta circle around it.


I have a hard time picturing somebody flying much higher that 700
AGL with a 1,000 ft. ceiling. It's a lot more difficult to see ahead
if you're bumping right up against the clouds. You will usually
encounter some lower hanging scud and vis isn't very good at the
ceiling boundary. It's a lot more comfortable a few hundred feet down
(assuming flat terrain).

John Galban=====N4BQ (PA28-180)