Class G and E airspace

[Tj1376]

Why am I an idiot?

When does class G extend all the way up to 14.5k? I get class G can go up to 700agl if the magenta line is around an uncontrolled airport. What I don't understand is when class G goes up to 1200 agl and when it goes all the way up.

Do you all have any ideas on how I can keep this straight?

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[NJP_MAN]

Come out west where the mountains are and you will see G go up to fourteen five

 

[midlifeflyer]

In simplistic terms, in by far most of the country, unless Class G stops at a lower altitude, Class G stops at 1200 AGL. Class G to 1200 is the chart default.

Class G to 14,500 is getting harder and harder to find, even out west. In fact I was looking for some of the examples I know and can't find them. When it is there, it's with the blue shading (similar to the Class G to 700 shading) with the "soft side" to 1200 AGL and the hard side to 14,500 MSL.

 

[bobmrg]

Why am I an idiot?

When does class G extend all the way up to 14.5k? I get class G can go up to 700agl if the magenta line is around an uncontrolled airport. What I don't understand is when class G goes up to 1200 agl and when it goes all the way up.

Do you all have any ideas on how I can keep this straight?

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Do you have much experience flying in "one mile visibility and clear of all clouds"? It's no fun, because the weather can change to instrument meteorological conditions in a heartbeat. Take it easy on yourself and assume that Class E visibility and cloud clearance requirements extend to the ground everywhere.

For knowledge test questions, refer to any test prep book and memorize the answers. This kind of question presents an impractical, though not illegal, situation.

Bob Gardner

 

[Tj1376]

In simplistic terms, in by far most of the country, unless Class G stops at a lower altitude, Class G stops at 1200 AGL. Class G to 1200 is the chart default.



Class G to 14,500 is getting harder and harder to find, even out west. In fact I was looking for some of the examples I know and can't find them. When it is there, it's with the blue shading (similar to the Class G to 700 shading) with the "soft side" to 1200 AGL and the hard side to 14,500 MSL.

Ignoring the restricted and moa part of this pic, the inside of the blue line is G to 14.5? Outside would be G to 1200?

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[Tj1376]

Do you have much experience flying in "one mile visibility and clear of all clouds"? It's no fun, because the weather can change to instrument meteorological conditions in a heartbeat. Take it easy on yourself and assume that Class E visibility and cloud clearance requirements extend to the ground everywhere.



For knowledge test questions, refer to any test prep book and memorize the answers. This kind of question presents an impractical, though not illegal, situation.



Bob Gardner

Trust me, no worries here... This is study for a BFR, not a practical application.

TJ


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[Kritchlow]

Didn't they change the depiction some years back? I believe it used to show both sides shaded, one magenta, one blue, 700 and 1200 respectively. If there was no shade it was 14,500. That chart depiction may have changed with the elimination of the Continental Control Area designation.

Anyway, it used to be easier back in the day...

 

[MauleSkinner]

Do you have much experience flying in "one mile visibility and clear of all clouds"? ....

This kind of question presents an impractical, though not illegal, situation.

Bob Gardner

There's a lot of flying that can be done between 1 and 3 miles vis with adequate training and preparation with the right airplane, and I've found it to be very practical Over the years. Certainly preferable to launching an unprotected airplane into icing conditions per the alternate advice I've gotten numerous times over the years.

 

[bobmrg]

There's a lot of flying that can be done between 1 and 3 miles vis with adequate training and preparation with the right airplane, and I've found it to be very practical Over the years. Certainly preferable to launching an unprotected airplane into icing conditions per the alternate advice I've gotten numerous times over the years.

I rest my case. My logbooks have a lot of flying in them and I would still hesitate to venture into such marginal conditions under visual flight rules.

Bob

 

[ejensen]

There is class G above 18000.

 

[MauleSkinner]

I rest my case. My logbooks have a lot of flying in them and I would still hesitate to venture into such marginal conditions under visual flight rules.

Bob

Everybody's experience is different.

 

[Kritchlow]

There is class G above 18000.

If there is, it's reasonably new. The old Continental Control Area started at 14,500 and went to infinity. The old Positive Control Area, now Class A, was from 18,000 to 60,000.

 

[RussR]

Ignoring the restricted and moa part of this pic, the inside of the blue line is G to 14.5? Outside would be G to 1200?

I see nobody's answered you on this yet, so, yes, you are correct. 14.5k Class G is getting harder and harder to find. Even just 2 or 3 years ago, you could find a blue shaded line that went from (IIRC) North Dakota SW toward WY-ish, then generally southerly to the Mexican border, with a lot of zigs and zags and cutouts and such. Everything east of this line was 1200' Class G, everything west was 14.5k Class G unless otherwise shown, and, of course, large areas WERE otherwise shown.

Anymore, there are just a few self-enclosed areas of this airspace left. Eventually, I'm sure the last such area will go away, and then 20 years later references to it will be removed from the AIM and study materials and test questions...

 

[Hank S]

For knowledge test questions, refer to any test prep book and memorize the answers. This kind of question presents an impractical, though not illegal, situation.

Bob Gardner

Some test questions are just silly! I took an ASF Instrument Quiz, and missed a question about how far MALSR Lights extend from the runway, choosing "one half mile." The correct answer was 2400 feet. I was off by 240 feet . . . As if that's noticeable in the air in bad weather. Why do the Feds insist on splitting hairs on the answers? Some of these are just ridiculous, like interpolating fuel burn to the nearest 0.1 gph.

 

[bobmrg]

Some test questions are just silly! I took an ASF Instrument Quiz, and missed a question about how far MALSR Lights extend from the runway, choosing "one half mile." The correct answer was 2400 feet. I was off by 240 feet . . . As if that's noticeable in the air in bad weather. Why do the Feds insist on splitting hairs on the answers? Some of these are just ridiculous, like interpolating fuel burn to the nearest 0.1 gph.

First, I won't quibble with you about the test questions. ASA has a representative who goes to DC (together with the Kings, a Gleim rep, etc) to meet with those who prepare the questions and she tells me that they have already dropped some of the more egregious examples from the private test with the commercial and instrument in the works.

Second, are you comparing a question prepared by the Air Safety Foundation with one prepared by the FAA and then blaming the FAA? Doesn't compute.

Bob

 

[Jim Logajan]

There is class G above 18000.

If there is, it's reasonably new. The old Continental Control Area started at 14,500 and went to infinity. The old Positive Control Area, now Class A, was from 18,000 to 60,000.

I suspect he's thinking of the airspace where the terrain is already above 13,300 ft MSL, with the tallest such area in the U.S. being around Mt. McKinley (20,320) to 1500 AGL
[*] that pushes Class G to as high as 21,820 MSL. Above where Class A normally begins.


[*] See Part 71; specifically 71.33(b) where they dictate 1500 rather the usual 1200. Only an evil examiner would expect someone to know the unusual 1500 ft exception.

I see nobody's answered you on this yet, so, yes, you are correct. 14.5k Class G is getting harder and harder to find. Even just 2 or 3 years ago, you could find a blue shaded line that went from (IIRC) North Dakota SW toward WY-ish, then generally southerly to the Mexican border, with a lot of zigs and zags and cutouts and such. Everything east of this line was 1200' Class G, everything west was 14.5k Class G unless otherwise shown, and, of course, large areas WERE otherwise shown.

Anymore, there are just a few self-enclosed areas of this airspace left. Eventually, I'm sure the last such area will go away, and then 20 years later references to it will be removed from the AIM and study materials and test questions...

They are rarer, but 1O6 (Dunsmuir-Mott) and O89 (Fall River Mills) are two examples of airports that lie under Class G that goes to 14,500. The area of northern California/southern Oregon has quite a complex mixture of airspace where Class G ceiling is higher than the usual 1200 AGL:

http://skyvector.com/?ll=41.66085773112519,-121.46553039191048&chart=301&zoom=5

 

[MAKG1]

If there is, it's reasonably new. The old Continental Control Area started at 14,500 and went to infinity. The old Positive Control Area, now Class A, was from 18,000 to 60,000.

Not new. Class A and E exclude areas lower than 1200 AGL. There is at least one high mountain over 18000 and several over 14000.

 

[azure]

There are a couple of G to 14.5 areas in the UP of Michigan too - or at least there were, last time I checked.

 

[ejensen]

If there is, it's reasonably new. The old Continental Control Area started at 14,500 and went to infinity. The old Positive Control Area, now Class A, was from 18,000 to 60,000.

Don't forget Alaska. Denali is 20,322' so up to 21822' is class E by FAR.

§ 71.33 Class A airspace areas.
(a) That airspace of the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, from 18,000 feet MSL to and including FL600 excluding the states of Alaska and Hawaii, Santa Barbara Island, Farallon Island, and the airspace south of latitude 25°04'00" North.
(b) That airspace of the State of Alaska, including that airspace overlying the waters within 12 nautical miles of the coast, from 18,000 feet MSL to and including FL600 but not including the airspace less than 1,500 feet above the surface of the earth and the Alaska Peninsula west of longitude 160°00'00" West.

 

[ejensen]

I suspect he's thinking of the airspace where the terrain is already above 13,300 ft MSL, with the tallest such area in the U.S. being around Mt. McKinley (20,320) to 1500 AGL
[*] that pushes Class G to as high as 21,820 MSL. Above where Class A normally begins.


[*] See Part 71; specifically 71.33(b) where they dictate 1500 rather the usual 1200. Only an evil examiner would expect someone to know the unusual 1500 ft exception.

Evil for an examiner but fair game for a CFI to challenge a student.

 

[Old Geek]

There's a lot of flying that can be done between 1 and 3 miles vis with adequate training and preparation with the right airplane, and I've found it to be very practical Over the years. Certainly preferable to launching an unprotected airplane into icing conditions per the alternate advice I've gotten numerous times over the years.

This. Early morning flying, the Sacramento Valley can show 1000' foot ceilings up and down and diverging temp/dewpoint.

 

[eetrojan]

Why am I an idiot?

When does class G extend all the way up to 14.5k? I get class G can go up to 700agl if the magenta line is around an uncontrolled airport. What I don't understand is when class G goes up to 1200 agl and when it goes all the way up.

Do you all have any ideas on how I can keep this straight?

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I made this diagram when I was a student (so take it for what it's worth), but it shows my student-interpretation of the Class G ceilings, or Class E "floors", up near Mammoth Airport (KMMH) in Northern California.

Vignettes - hard edge is higher elevation, faded side is lower elevation. For example:

The magenta vignettes that define the 1200/700 Glass G border have the hard edge on the higher side (1200 AGL), and the faded side represents the lower side (700 AGL). Note that it kinds of looks like that too.

The blue vignettes that define the 14500/1200 Class G border have the hard edge on the higher side (14500 MSL), and the faded side represent the lower side (usually 1200 AGL, but note the 12000 MSL "zipper" area on the left of the 14500 MSL zone).

 

[Pilawt]

Low visibility conditions are not created equal. I learned to fly in the smoggy eastern half of the Los Angeles Basin in the 1960s. If we couldn't fly VFR (or special VFR) in 1-3 mile visibility, we'd never fly.

 

[eetrojan]

Here's the same cross-section with my potentially incorrect interpretation of the VFR visibility requirements in the "Vis-ABC" format where:

5-111
5 miles visibility
1,000 above, 1,000 below, and 1 mile clear of clouds

1-152 or 3-152
1 or 3 miles visibility
1,000 above, 500** below, 2,000 clear of clouds
(**edit: oops, 500, not 5000!)

1-COC
1 mile visibility
clear of clouds

and, where it matters, with the day/night condition indicated by a sun icon or a moon icon.

 

[Pilawt]

Didn't they change the depiction some years back? I believe it used to show both sides shaded, one magenta, one blue, 700 and 1200 respectively. If there was no shade it was 14,500.

Yes. This is from the Los Angeles Sectional, 5th Edition, 1969*. I don't recall when the back-to-back shading was eliminated.

On this chart, over the ocean west of Imperial Beach, is one of those rare places where the floor was 700' on one side of the line, and 14,500' on the other, with no area of 1200' floor inbetween.

(*Richard Nixon was President, and Prohibited Area P-25 was for the "Western White House" at San Clemente -- 1 statute mile radius and only up to 4,000' MSL, even when he was there.)

 

[Tj1376]

I made this diagram when I was a student (so take it for what it's worth), but it shows my student-interpretation of the Class G ceilings, or Class E "floors", up near Mammoth Airport (KMMH) in Northern California.



Vignettes - hard edge is higher elevation, faded side is lower elevation. For example:



The magenta vignettes that define the 1200/700 Glass G border have the hard edge on the higher side (1200 AGL), and the faded side represents the lower side (700 AGL). Note that it kinds of looks like that too.



The blue vignettes that define the 14500/1200 Class G border have the hard edge on the higher side (14500 MSL), and the faded side represent the lower side (usually 1200 AGL, but note the 12000 MSL "zipper" area on the left of the 14500 MSL zone).

This is super helpful! Many thanks!


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[Tj1376]

Here's the same cross-section with my potentially incorrect interpretation of the VFR visibility requirements in the "Vis-ABC" format where:



5-111

5 miles visibility

1,000 above, 1,000 below, and 1 mile clear of clouds



1-152 or 3-152

1 or 3 miles visibility

1,000 above, 5,000 below, 2,000 clear of clouds



1-COC

1 mile visibility

clear of clouds



and, where it matters, with the day/night condition indicated by a sun icon or a moon icon.

This is also awesome, but your 152 is slightly askew. It's 500 feet below, not 5000!

I actually just stole your idea and made one for my local area (which I am new to flying in.) I'm based out of 0n0 which sits right under the class B of KMCI.. I need to make sure I know my airspace so I don't have a friendly chat with authorities.

Thanks for everyone's help!


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[Pilawt]

In this 1957 sectional chart, all controlled airspace was shaded. The legend, though, doesn't indicate what the vertical limits of controlled airspace would have been in those days.

How did pilots in those days react to the depiction of controlled airspace on VFR charts? Look at Frank Kingston Smith's Weekend Pilot column "Positively Colorful" in the January 1964 issue of Flying magazine:
https://books.google.com/books?id=IXU6sCejpKYC&printsec=frontcover#v=onepage&q&f=false (scroll down to page 100)

 

[eetrojan]

These old charts are really cool. Thanks!

 

[Tj1376]

In this 1957 sectional chart, all controlled airspace was shaded. The legend, though, doesn't indicate what the vertical limits of controlled airspace would have been in those days.

How did pilots in those days react to the depiction of controlled airspace on VFR charts? Look at Frank Kingston Smith's Weekend Pilot column "Positively Colorful" in the January 1964 issue of Flying magazine:
https://books.google.com/books?id=IXU6sCejpKYC&printsec=frontcover#v=onepage&q&f=false (scroll down to page 100)

I remember my grandpa saying something similar when I was learning how to fly (almost twenty years ago.) It is crazy to compare the charts from yesteryear to the charts today... I mean, where is the magenta line to follow? What's a grease pencil?

Thanks for sharing. Reading the article really made me remember some old stories from my childhood. Thank you!


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[midlifeflyer]

Ignoring the restricted and moa part of this pic, the inside of the blue line is G to 14.5? Outside would be G to 1200?

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You were already answered by someone else, but yes, that's right.

 

[Kritchlow]

Don't forget Alaska. Denali is 20,322' so up to 21822' is class E by FAR.

§ 71.33 Class A airspace areas.
(a) That airspace of the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, from 18,000 feet MSL to and including FL600 excluding the states of Alaska and Hawaii, Santa Barbara Island, Farallon Island, and the airspace south of latitude 25°04'00" North.
(b) That airspace of the State of Alaska, including that airspace overlying the waters within 12 nautical miles of the coast, from 18,000 feet MSL to and including FL600 but not including the airspace less than 1,500 feet above the surface of the earth and the Alaska Peninsula west of longitude 160°00'00" West.

I was debating if I should keep it to the continental United States, or mention outside. Guess I went the wrong way.

 

[Kritchlow]

Yes. This is from the Los Angeles Sectional, 5th Edition, 1969*. I don't recall when the back-to-back shading was eliminated.

On this chart, over the ocean west of Imperial Beach, is one of those rare places where the floor was 700' on one side of the line, and 14,500' on the other, with no area of 1200' floor inbetween.

(*Richard Nixon was President, and Prohibited Area P-25 was for the "Western White House" at San Clemente -- 1 statute mile radius and only up to 4,000' MSL, even when he was there.)

Yup... That's it!! That was around back when I was a CFI in the late 80's.

 

[Palmpilot]

I was debating if I should keep it to the continental United States, or mention outside. Guess I went the wrong way.

Alaska is in the continental United States.

 

[Kritchlow]

Alaska is in the continental United States.

I have actually seen it defined both ways. That said, if that's the biggest debate here, we are in good shape!

 

[Palmpilot]

I have actually seen it defined both ways.

I've seen "CONUS" defined in different ways. Some people use "contiguous" United States when they want to exclude Alaska.

http://www.acronymfinder.com/CONUS.html

That said, if that's the biggest debate here, we are in good shape!

True!

 

[onezuludelta]

Class G to 14,500 is getting harder and harder to find, even out west. In fact I was looking for some of the examples I know and can't find them. When it is there, it's with the blue shading (similar to the Class G to 700 shading) with the "soft side" to 1200 AGL and the hard side to 14,500 MSL.

I see nobody's answered you on this yet, so, yes, you are correct. 14.5k Class G is getting harder and harder to find.
Anymore, there are just a few self-enclosed areas of this airspace left. Eventually, I'm sure the last such area will go away, and then 20 years later references to it will be removed from the AIM and study materials and test questions...

Sorry to zombie-thread this, but I was just taking one of those AOPA ASF courses, this one about airspace (wild weekend for me, woooo!), and got to the part about the Class G up to 14,500 MSL. I looked up the airport in their figure - Class G is gone. Did some Googling to other articles about it, looked up near the airports in their examples - also gone. I can't find a single zipper line, and the only blue-line-up-to-14,5000 i can find are the little bits W and N of Aberdeen, SD. I looked for articles about it, but I guess all the others (in the continental US at least) been quietly removed?

Interesting. Like some of the other posters said though, I have no desire to be up in 1 mile viz near clouds, anyway,

 

[Larry in TN]

I would recommend thinking of this differently in order to make it easier to understand and remember. Think of it as, "Class G goes up to 14,500' everywhere, except where a higher class airspace is depicted"

The areas where a higher class airspace is not depicted are becoming difficult to find but Class G up to 14,500' is the default.

 

[onezuludelta]

I would recommend thinking of this differently in order to make it easier to understand and remember. Think of it as, "Class G goes up to 14,500' everywhere, except where a higher class airspace is depicted"

The areas where a higher class airspace is not depicted are becoming difficult to find but Class G up to 14,500' is the default.

I don't have trouble remembering it, I just thought it was interesting that they were disappearing. I think I would disagree though, anyway. Since 99% of the non-B/C/D/E-down-to-700 airspace is E-down-to-1,200, I would think of E-down-to-1,200 as the default. If I show a non-pilot a sectional and try to explain it to them, all of the non-colored area (which would be my default starting point in the explanation) will be E-down-to-1,200, unless I'm looking at that ONE spot near South Dakota.

Edit, though, there are some zippered lines I found north of Vegas, near all those Restricted areas. I'd avoid all that Area 51 mess VFR anyway, though.

 

[John Collins]

Almost all of the "high" class G airspace has been eliminated by airspace changes through the regulatory process completed during the last 12 months. The remaining few areas are slated for regulation changes. Class G above 1200 AGL in the CONUS is for the most part a memory.