Airspace Question - Class G Airspace

azpilot

azpilot

Line Up and Wait
Joined
Jul 27, 2015
Messages
823
Display Name
Display name:
azpilot
Per 'the book' class G airspace can go up to 14,500' MSL. But in practice, is there anywhere in the US where that happens?

One of the notes on the sectional chart says this:

upload_2022-9-14_15-29-1.png

And then there's this bold method article that claims the class G airspace shown goes all the way to 14,500 MSL (really 14,499).

https://www.boldmethod.com/learn-to-fly/airspace/class-g-airspace-explained/

upload_2022-9-14_15-30-3.png

I can't find anywhere on the ABQ sectional where it says that the ceiling of the class G airspace in that box is.

Any ideas? When I see that light gray/blue shaded boundary, how do I know what the ceiling of the class G airspace is? The sectional note for the shaded gray/blue line says the class G airspace goes up to 1,200' AGL or greater (emphasis mine).

I know this is really splitting hairs, but I'm ramping up to take my written for my instrument, and I really want to make sure I know this stuff.
 
Depends on your perspective. The heads of those white arrows in the second pic point to the outside of the boundary. The tails of those white arrows point towards the inside.
 
azpilot said:
Per 'the book' class G airspace can go up to 14,500' MSL. But in practice, is there anywhere in the US where that happens?

One of the notes on the sectional chart says this:

View attachment 110521

And then there's this bold method article that claims the class G airspace shown goes all the way to 14,500 MSL (really 14,499).

https://www.boldmethod.com/learn-to-fly/airspace/class-g-airspace-explained/

View attachment 110522

I can't find anywhere on the ABQ sectional where it says that the ceiling of the class G airspace in that box is.

Any ideas? When I see that light gray/blue shaded boundary, how do I know what the ceiling of the class G airspace is? The sectional note for the shaded gray/blue line says the class G airspace goes up to 1,200' AGL or greater (emphasis mine).

I know this is really splitting hairs, but I'm ramping up to take my written for my instrument, and I really want to make sure I know this stuff.
Click to expand...
By definition, Class E begins at 14,500 MSL unless otherwise noted. Within that area, there's no ceiling noted for the Class G, so it goes up to the floor of the E at 14,500. The shaded side of the blue line is towards to Class E beginning at 1,200'. The legend tells you the other side abuts G.
 
Lindberg said:
By definition, Class E begins at 14,500 MSL unless otherwise noted. Within that area, there's no ceiling noted for the Class G, so it goes up to the floor of the E at 14,500. The shaded side of the blue line is towards to Class E beginning at 1,200'. The legend tells you the other side abuts G.
Click to expand...

Ok, so in that highlighted portion of the sectional, since there is no indication where the class E starts, that means, that by definition, it starts at 14,500. Is that correct?
 
A much more interesting question that you might get asked on a checkride is, "At what altitude does Class E begin outside the magenta line, and how do you know?"

upload_2022-9-14_18-13-39.png
 
azpilot said:
Per 'the book' class G airspace can go up to 14,500' MSL. But in practice, is there anywhere in the US where that happens?

One of the notes on the sectional chart says this:

View attachment 110521
And then there's this bold method article that claims the class G airspace shown goes all the way to 14,500 MSL (really 14,499).

https://www.boldmethod.com/learn-to-fly/airspace/class-g-airspace-explained/

View attachment 110522

I can't find anywhere on the ABQ sectional where it says that the ceiling of the class G airspace in that box is.

Any ideas? When I see that light gray/blue shaded boundary, how do I know what the ceiling of the class G airspace is? The sectional note for the shaded gray/blue line says the class G airspace goes up to 1,200' AGL or greater (emphasis mine).

I know this is really splitting hairs, but I'm ramping up to take my written for my instrument, and I really want to make sure I know this stuff.
Click to expand...
Here’s another piece

upload_2022-9-14_16-36-48.png
 
Lindberg said:
By definition, Class E begins at 14,500 MSL unless otherwise noted. Within that area, there's no ceiling noted for the Class G, so it goes up to the floor of the E at 14,500. The shaded side of the blue line is towards to Class E beginning at 1,200'. The legend tells you the other side abuts G.
Click to expand...
upload_2022-9-14_16-41-28.png
 
Lindberg said:
A much more interesting question that you might get asked on a checkride is, "At what altitude does Class E begin outside the magenta line, and how do you know?"

View attachment 110523
Click to expand...
Yeah. That's a good one. Sometimes you have to look pretty far to find the blue shaded line surrounding the area. Like to Canada, Mexico, or one of the oceans.
 
Lindberg said:
Not really, the blue vignette is "otherwise designated as shown above."
Click to expand...

"Class E begins at 14,500 MSL unless otherwise noted"

It begins at 1,200' AGL unless otherwise noted.
 
Some sectionals don't have any Class E floors above 1,200' AGL so they don't depict it. You won't find information in a setional's legend that don't exist on that chart.
 
Larry in TN said:
Some sectionals don't have any Class E floors above 1,200' AGL so they don't depict it. You won't find information in a setional's legend that don't exist on that chart.
Click to expand...
I don’t think even the few Charts that have 14,500 Floor E Airspace acknowledge that in the Legend. You have to already know about that.
 
Lindberg said:
A much more interesting question that you might get asked on a checkride is, "At what altitude does Class E begin outside the magenta line, and how do you know?"

View attachment 110523
Click to expand...

That image is too small to make out exactly what airport it is. So let's use Winslow airport as an example (KINW). The faded magenta line means that the class E airspace has a floor of 700' AGL. It laterally abuts class E airspace with a floor of 1200' or higher. The other note on the sectional chart says that class E airspace starts at 1200' AGL, unless otherwise noted. I don't see any notes indicating otherwise, so I would say that outside the faded magenta line, class E airspace starts at 1200' AGL. Inside the the faded magenta line, the class E airspace starts at 700' AGL. And then inside the dashed magenta line, the class E airspace goes all the way to the surface.

upload_2022-9-15_9-35-45.png
 
azpilot said:
That image is too small to make out exactly what airport it is. So let's use Winslow airport as an example (KINW). The faded magenta line means that the class E airspace has a floor of 700' AGL. It laterally abuts class E airspace with a floor of 1200' or higher. The other note on the sectional chart says that class E airspace starts at 1200' AGL, unless otherwise noted. I don't see any notes indicating otherwise, so I would say that outside the faded magenta line, class E airspace starts at 1200' AGL. Inside the the faded magenta line, the class E airspace starts at 700' AGL. And then inside the dashed magenta line, the class E airspace goes all the way to the surface.

View attachment 110542
Click to expand...

What about airspace on a Victor airway?
 
Walboy said:
What about airspace on a Victor airway?
Click to expand...
I've always seen class E airspace associated with a Victor airway charted on the sectional, although as I sit here I can't think of a place in the USA where this is still going to be visible on the chart. That is, a place with a Victor airway through it where the class E floor is otherwise 14,500. Charts from maybe 5 years ago would still have examples, though, where the blue vignette lines appear on either side of the airway.

Edit to add: I found at least a half example. V264 between SJN and ONM.
 
Last edited:
Walboy said:
What about airspace on a Victor airway?
Click to expand...
I believe victor airways exist from the floor of class E airspace up to 17,999 MSL. But Victor airways can cross B, C and D airspace. V16 leaves PXR and heads south across KCHD's delta on its way to TOTEC. So V16 between PXR and TOTEC exists in B, D and E airspace.... I think...
 
azpilot said:
I believe victor airways exist from the floor of class E airspace up to 17,999 MSL. But Victor airways can cross B, C and D airspace. V16 leaves PXR and heads south across KCHD's delta on its way to TOTEC. So V16 between PXR and TOTEC exists in B, D and E airspace.... I think...
Click to expand...

Apply what you know about Victor airways to the Winslow example.
 
azpilot said:
That image is too small to make out exactly what airport it is. So let's use Winslow airport as an example (KINW). The faded magenta line means that the class E airspace has a floor of 700' AGL. It laterally abuts class E airspace with a floor of 1200' or higher. The other note on the sectional chart says that class E airspace starts at 1200' AGL, unless otherwise noted. I don't see any notes indicating otherwise, so I would say that outside the faded magenta line, class E airspace starts at 1200' AGL. Inside the the faded magenta line, the class E airspace starts at 700' AGL. And then inside the dashed magenta line, the class E airspace goes all the way to the surface.

View attachment 110542
Click to expand...
It says 1200' or higher. Now we from what we've talking about so far, that is almost always 1200 but can be higher. As high as 14,500. To prove beyond a doubt it's 1200, by just looking at the Chart, you'd have to look out and find a shaded blue line, indicating that the sky around there is 1200 sky.
 
Walboy said:
Apply what you know about Victor airways to the Winslow example.
Click to expand...
I'll use V291 as an example. From INW to the dashed magenta line, V291 exists from the surface to 17,999 MSL (my red line). From the dashed magenta line, to the shaded magenta line, it exists from 700 AG to 17,999 MSL (my green line), and the remainder of V291 would be from 1200 AGL to 17,999 MSL (my yellow line).

EDIT

This is wrong.

"Unless otherwise specified— Each Federal airway includes that airspace extending upward from 1,200 feet above the surface of the earth (or higher) to, but not including, 18,000 feet MSL, except that Federal airways for Hawaii have no upper limits."

https://www.faa.gov/air_traffic/publications/atpubs/pham_html/chap20_section_3.html



upload_2022-9-15_10-48-15.png
 
Last edited:
azpilot said:
I believe victor airways exist from the floor of class E airspace up to 17,999 MSL. But Victor airways can cross B, C and D airspace. V16 leaves PXR and heads south across KCHD's delta on its way to TOTEC. So V16 between PXR and TOTEC exists in B, D and E airspace.... I think...
Click to expand...
The MEA is 5000. KCHD's D only goes up to 3000. So it's not in D.

EDIT: Gotta think about this more. The floor of an Airway is probably 1200 AGL regardless of MIA

More EDIT: It's 1200.
e. Federal Airways. The Federal airways and low altitude RNAV routes are Class E airspace areas and unless otherwise specified, extend upward from 1,200 feet to, but not including, 18,000 feet MSL. The colored airways are green, red, amber, and blue. The VOR airways are classified as Domestic, Alaskan, and Hawaiian.
 
Last edited:
azpilot said:
I'll use V291 as an example. From INW to the dashed magenta line, V291 exists from the surface to 17,999 MSL (my red line). From the dashed magenta line, to the shaded magenta line, it exists from 700 AG to 17,999 MSL (my green line), and the remainder of V291 would be from 1200 AGL to 17,999 MSL (my yellow line).

View attachment 110545
Click to expand...
Airways do not exist from the Surface. They exist where they are established. They have Minimum Altitudes. When the airway is established, that establishes Controlled Airspace. Class E Surface Areas end where other Controlled Airspace starts. V291 is not in the the KINW Surface Area.

AIM 3-2-6 e. 1.
1. Surface area designated for an airport where a control tower is not in operation. Class E surface areas extend upward from the surface to a designated altitude, or to the adjacent or overlying controlled airspace. The airspace will be configured to contain all instrument procedures.
 
Last edited:
luvflyin said:
The MEA is 5000. KCHD's D only goes up to 3000. So it's not in D.
Click to expand...
Is there a regulation saying that the MEA defines the floor of the airway?
 
azpilot said:
That image is too small to make out exactly what airport it is. So let's use Winslow airport as an example (KINW). The faded magenta line means that the class E airspace has a floor of 700' AGL. It laterally abuts class E airspace with a floor of 1200' or higher. The other note on the sectional chart says that class E airspace starts at 1200' AGL, unless otherwise noted. I don't see any notes indicating otherwise, so I would say that outside the faded magenta line, class E airspace starts at 1200' AGL. Inside the the faded magenta line, the class E airspace starts at 700' AGL. And then inside the dashed magenta line, the class E airspace goes all the way to the surface.

View attachment 110542
Click to expand...
How far did you look to see if it was otherwise noted?
 
You guys are answering your own questions, which is great! The extra effort will definitely show during the oral portion of your checkride.

You're showing the four levels of learning:

Rote
Understanding
Application
Correlation
 
Lindberg said:
How far did you look to see if it was otherwise noted?
Click to expand...
I don't see anywhere on the Phoenix Sectional chart that indicates that the class G airspace around Winslow (KINW) goes any higher than 1,200' AGL.
 
Walboy said:
You guys are answering your own questions, which is great! The extra effort will definitely show during the oral portion of your checkride.

You're showing the four levels of learning:

Rote
Understanding
Application
Correlation
Click to expand...
You completely left out:
  • Passed the test a few years ago and still benefit from a ground quiz now and then
In fairness, the FAA is the one that left that out of FOI, but I think it's one of the long-term safety benefits of participating in forums like this.
 
iamtheari said:
it's one of the long-term safety benefits of participating in forums like this.
Click to expand...

Agreed.

Now if some of the snarkiness and condencension could be set aside, there would probably be a lot more participation.
 
coma24 said:
Pffft, this is nothing. You should come over to the VFR cruising altitude thread. :)
Click to expand...

I haven't detected snark in this thread, everyone seems to be playing well here. I meant snark in general. No offense to @iamtheari if my remark came across that way.

Here's an example of snark from @steingar in another thread from someone asking for help with their landings.

steingar said:
If you can't land a Cherokee you can't land. I don't think there's ever been an easier airplane to land.
Click to expand...
 
Ain't snark, just truth as I see it. I don't think I've ever flown an easier to land airplane. Easy to land really well is another matter entirely. But if you don't like my postings you won't have to suffer though them much longer.

Walboy said:
Here's an example of snark from @steingar in another thread from someone asking for help with their landings.
Click to expand...
 
You must log in or register to reply here.
Back
Top