Floor of Class E airspace

[RIlls]

I have a question about different information in Foreflight vs a sectional chart re the floor of Class E airspace. This is mainly an academic exercise but could have real world implications.

Let’s say I am going in or out of Little River CA VFR. Looking at a sectional chart on Foreflight (see attached) I would assume that class E starts at 700 agl around the airport based on the magenta ring. This would be my interpretation if I just had a paper chart. Nothing in the AF/D would tell me differently.

But with Foreflight, if I select the aeronautical map overlay it adds a whole new area with an indication that class E starts at 5,500 feet mal. (See attached).

So is the airspace above 700 feet above the airport Class G or E?

I think the significance of the distinction is that for day flight above 1200 agl the required visability would be 1 mile if this is G airspace and 3 miles if E airspace. Same distances from clouds. But what about the airspace between 700 feet and 1200 in this situation? Only 1 mile and clear of clouds if the class E does not start until 5500 msl.

The distinction could be important if you climb to 900 feet AGL under a 1000 foot ceiling. If the magenta transition area ring controls, you are in Class E above 700 feet and do not have the required cloud clearance. If the depiction of 5500 foot start of class E controls, you are fine.

This scenario is probably not uncommon at this airport. There is often a marine layer that rolls in over the airport from the ocean but the weather is severe clear a mile to the east.

My other question is about Foreflight vs a sectional chart. Why does this 5500 class E airspace show up with the aeronautical overlay but not on a regular sectional? Come to think of it, it you use the aeronautical overlay without a sectional underneath it, you don’t get a depiction of the magenta 700 foot transition areas anywhere on the chart.

Perhaps I am not up to speed on airspace or chart interpretation- if so I am sure I will hear about it I use the aeronautical overlay over a sectional base, so I get all of this info, but I could see some confusion if you used only a sectional or only the aeronautical map.

Anyone have any thoughts on this?

 

[flyingron]

The magenta vignette area is a 700' transition area. The 700' itself is in the class E. 699 is class G. The stuff you're talking about in 91.155 is different rules for different altitudes in class G, it has nothing to dow with being in controlled airspace or not.

 

[Country Flier]

I have a question about different information in Foreflight vs a sectional chart re the floor of Class E airspace. This is mainly an academic exercise but could have real world implications.

Let’s say I am going in or out of Little River CA VFR. Looking at a sectional chart on Foreflight (see attached) I would assume that class E starts at 700 agl around the airport based on the magenta ring. This would be my interpretation if I just had a paper chart. Nothing in the AF/D would tell me differently.

But with Foreflight, if I select the aeronautical map overlay it adds a whole new area with an indication that class E starts at 5,500 feet mal. (See attached).

So is the airspace above 700 feet above the airport Class G or E?

I think the significance of the distinction is that for day flight above 1200 agl the required visability would be 1 mile if this is G airspace and 3 miles if E airspace. Same distances from clouds. But what about the airspace between 700 feet and 1200 in this situation? Only 1 mile and clear of clouds if the class E does not start until 5500 msl.

The distinction could be important if you climb to 900 feet AGL under a 1000 foot ceiling. If the magenta transition area ring controls, you are in Class E above 700 feet and do not have the required cloud clearance. If the depiction of 5500 foot start of class E controls, you are fine.

This scenario is probably not uncommon at this airport. There is often a marine layer that rolls in over the airport from the ocean but the weather is severe clear a mile to the east.

My other question is about Foreflight vs a sectional chart. Why does this 5500 class E airspace show up with the aeronautical overlay but not on a regular sectional? Come to think of it, it you use the aeronautical overlay without a sectional underneath it, you don’t get a depiction of the magenta 700 foot transition areas anywhere on the chart.

Perhaps I am not up to speed on airspace or chart interpretation- if so I am sure I will hear about it I use the aeronautical overlay over a sectional base, so I get all of this info, but I could see some confusion if you used only a sectional or only the aeronautical map.

It looks like E is at 700 foot above the airport. The other area that FF is showing...does show up on an IFR chart, but as a mid-westerner with no west coast experience, I can only guess that it is FAA/DOD control...?

I found this:

https://static1.squarespace.com/sta...e58c62fe0ea77ea8/1472241775686/03+02+1993.pdf

 

[RIlls]

The magenta vignette area is a 700' transition area. The 700' itself is in the class E. 699 is class G. The stuff you're talking about in 91.155 is different rules for different altitudes in class G, it has nothing to dow with being in controlled airspace or not.

 

[RIlls]

Yes, maybe sloppy terminology on my part.

So if you think class E starts at 700 feet AGL (which is what I assume too based on my magenta transition ring) what is the significance of the blue indication on the Foreflight aeronautical overlay indicating Class E starts at 5500 MSL?

 

[RIlls]

I think I have it. This is part of an “offshore controlled area” that happens to extend inland. The general purpose is to authorize domestic ATC separation services for international over water flights.

Here is a description. https://www.faa.gov/air_traffic/publications/atpubs/pham_html/chap19_section_1.html#:~:text=Offshore%2FControl%20Airspace%20Areas%20are,be%20used%20for%20separation%20purposes.

So.. I agree it has nothing to do with weather minimums. For weather minimums, class E starts at 700 feet. The confusion for me was that Foreflight depicts it with an E but it is not really the floor of the E airspace. And I can see why it is not relevant information on a sectional chart.

Midwesterners get bonus points for helping me decipher a bit of esoteric information they will never have to use.

 

[luvflyin]

I have a question about different information in Foreflight vs a sectional chart re the floor of Class E airspace. This is mainly an academic exercise but could have real world implications.

Let’s say I am going in or out of Little River CA VFR. Looking at a sectional chart on Foreflight (see attached) I would assume that class E starts at 700 agl around the airport based on the magenta ring. This would be my interpretation if I just had a paper chart. Nothing in the AF/D would tell me differently.

But with Foreflight, if I select the aeronautical map overlay it adds a whole new area with an indication that class E starts at 5,500 feet mal. (See attached).

So is the airspace above 700 feet above the airport Class G or E?

I think the significance of the distinction is that for day flight above 1200 agl the required visability would be 1 mile if this is G airspace and 3 miles if E airspace. Same distances from clouds. But what about the airspace between 700 feet and 1200 in this situation? Only 1 mile and clear of clouds if the class E does not start until 5500 msl.

The distinction could be important if you climb to 900 feet AGL under a 1000 foot ceiling. If the magenta transition area ring controls, you are in Class E above 700 feet and do not have the required cloud clearance. If the depiction of 5500 foot start of class E controls, you are fine.

This scenario is probably not uncommon at this airport. There is often a marine layer that rolls in over the airport from the ocean but the weather is severe clear a mile to the east.

My other question is about Foreflight vs a sectional chart. Why does this 5500 class E airspace show up with the aeronautical overlay but not on a regular sectional? Come to think of it, it you use the aeronautical overlay without a sectional underneath it, you don’t get a depiction of the magenta 700 foot transition areas anywhere on the chart.

Perhaps I am not up to speed on airspace or chart interpretation- if so I am sure I will hear about it I use the aeronautical overlay over a sectional base, so I get all of this info, but I could see some confusion if you used only a sectional or only the aeronautical map.

Anyone have any thoughts on this?

Go to Settings, Aeronautical, Airspace. It will say Custom. Tap that. Show Airspace will be selected. Turn it off. Control 1486 will go away on the Aeronautical Chart. Play around with all that stuff. More about this here https://www.pilotsofamerica.com/community/threads/foreflight-airspace.141151/