Class E/G Sectional Chart Airspace Question

Trogdor

Trogdor

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Trogdor
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Ok, question: Notice that the airport 39N (my home) would appear to be in Class G up to 1200 and Class E up to 18000.

However, it seems that both the EWR/PHL areas have a HUGE class E magenta around them (basically the entire Northeast is under magenta). Consequently, that means class G ends at 700 and we are in E. Ok. fine. I totally get that.

But then why is the Princeton golf course surrounded by magenta (the area Southwest of 39N) if the entire airspace surrounding it already is? Clarity? That's what has me a bit confused.
 
I think you have it backwards, that narrow triangular sliver is 1200, while everything else nearby is 700.
 
39N is inside the area where Class E starts at 700. The skinny triangle has Class E starting at 1200.
 
Trogdor said:
View attachment 93603
Ok, question: Notice that the airport 39N (my home) would appear to be in Class G up to 1200 and Class E up to 18000.

However, it seems that both the EWR/PHL areas have a HUGE class E magenta around them (basically the entire Northeast is under magenta). Consequently, that means class G ends at 700 and we are in E. Ok. fine. I totally get that.

But then why is the Princeton golf course surrounded by magenta (the area Southwest of 39N) if the entire airspace surrounding it already is? Clarity? That's what has me a bit confused.
Click to expand...

Chunks of different 700 E designations some times get very close to each other but just quite don’t overlap so little slivers of 1200 E happen.
 
Oh crap! I see what you are all saying. The magenta isn't surrounding the triangle it is EXCLUDING it. Grrrrrr! Thanks folks. I don't know how I missed this (on first glance it looks like a sliver of magenta surrounding it).
 
luvflyin said:
Chunks of different 700 E designations some times get very close to each other but just quite don’t overlap so little slivers of 1200 E happen.
Click to expand...
It's kind of like taking as much orange juice as you want from the bottle and putting in back in the fridge, not even realizing you left a tiny portion behind.
 
Seems pointless to do that. That little sliver of airspace is useless as Class G airspace. Might as well make it all Class E to 700 feet.
 
Greg Bockelman said:
Seems pointless to do that. That little sliver of airspace is useless as Class G airspace. Might as well make it all Class E to 700 feet.
Click to expand...

Yeah. Changing the actual dimensions of the 700 foot pieces would be tedious, I think it requires all kinds of rule making federal register hoops to jump through stuff. But letting the Chart Makers just ignore those little useless pieces should be easy enough.
 
Trogdor said:
Oh crap! I see what you are all saying. The magenta isn't surrounding the triangle it is EXCLUDING it. Grrrrrr! Thanks folks. I don't know how I missed this (on first glance it looks like a sliver of magenta surrounding it).
Click to expand...

You ain't the first to do that. I of course never made that mistake

upload_2021-1-28_8-34-21.jpeg
 
luvflyin said:
Yeah. Changing the actual dimensions of the 700 foot pieces would be tedious, I think it requires all kinds of rule making federal register hoops to jump through stuff. But letting the Chart Makers just ignore those little useless pieces should be easy enough.
Click to expand...
I think the issue isn't so much about the hoops. Yes, they do file both Proposed and Final rules, but it's rare for there to be comments or objections unless it's some controversial Class B or C change. There are almost literally airspace changes and additions published every day. I have a feeling (which means I don't really know) it's about how 700 AGL Class E is designed. They are designed to accommodate specific approaches and there is probably some design guidance which covers exactly how the metes and bounds are determined, regardless of what else is there. After all, you wouldn't want to government to take more than it needs, would you? :eek::D:p

Example. This is from today's Federal Register. (See how easy it is to find one?) It covers a couple of things in Nashville, TN, including some Class E amendments. What is interesting in the context of this discussion is the creation of a brand new 700 Class E to accommodate new instrument approaches at the Vanderbilt University heliport. Here's the BNA airspace. The arrow points to the Vanderbilt heliport. It's already covered by the extensions for all the other airports nearby, yet there is a new one — 6 mile radius — being "created" for its new approaches. I'm not surprised there are gaps. We see the same thing in the few Class G to 14,500 spaces floating around hither and yon.

upload_2021-1-28_14-13-45.png
 
airspace with the faded magenta line is optional*






*I used to tell people that a stop sign that has a white border around it is optional too, so........
 
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