Airspace Tiers

Many of you should know what an airspace is but many users do not know what the airspace tiers are or mean. In IF the airspace is the outermost blue ring around an airport. Simple enough. But wait, larger class B,C, and D airports have more than one ring. What do those mean? Well those are the different levels, or tiers, of an airspace.

The outermost ring is the entire airspace where a Tower ATC may have jurisdiction in the absence of a departure and approach controller. This airspace general extends from where the second tier tops out until FL120. The middle ring you see in a class B airspace, or the outermost ring for a class C/D airspace is where a speed restriction is put in place (more on that later). This airspace varies for class B airspaces but always tops out at 4000MSL for class C/D airspaces. The ring closest to the airport also has a speed restriction near identical to the second tier ring. This tier extends from the airport up to the ceiling of 2000MSL.

In regards to speed restrictions this is where it becomes very important about the airspaces. When withing the tiers for a class C/D airspace or within the second tier down to the first tier for a class B airspace you are always restricted to 200IAS. That applies to all flight unless grester IAS is needed to operate the aircraft safely. This speed restriction is also alongside noise abatment programs for that airpsace, always noted on a STAR/SID chart.

What does that mean for my flights?
Well nothing if your not trying to be realistic, but if you are on Expert server and trying to be as realistic as possible you need to restrict your IAS to 200 until you pass through the ceiling if the 2nd tier or that you need to decrease your speed to 200IAS on approach once you descend below the tier 2 ceiling. Yes doing so will make your flight longer but in real life pilots have to obey these rules.

How can i tell if I’m in the tier for an airspace?
Unless you have the information in front of you their is no way of knowing what the ceiling is for the 2nd tier of a class B airpsace. However; IF did a wonderful job of showing you on the flight map if you are in the tier of an airspace and what tier you are in

Look at the HUD map you can see one of the airspace rings is green. That means I’m in the 3rd tier airspace. When an airspace ring lights up that means you are flying in that airspace tier. It’s very helpful. The developers also did a great job of inputing the ceiling data for the 2nd tier. The simulator knows when you enter or leave a tier by either lighting the ring up green for entering the tier or turning it blue for leaving the tier while turning the next tier green.

Here is a link to show the visual representations for airspaces and the tiers. Airspace class (United States) - Wikipedia


Great and valuable tutorial post containing some really well explained information ! Thanks so much for making it @anon2063420 :)


Helpful much! :)

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Nice post the highest a Bravo will go is 12,000 feet MSL though not 14,000. However most are 10,000 MSL.


I do apologized. My brain is overloaded with Spanish right now as Im in language school for 3 months. I confused the 14,500 ceiling of a class E airspace with the ceiling of a Class B airspace

No worries

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This is a great post. It contains very thorough and accurate information! Well done, this is a post to be proud of.

Thanks for the info, good to know

Good tutorial. These altitudes are AGL though, not MSL - they go from SFC up to 2000 feet AGL etc.

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very useful. 10/10 would recommend to a neighbor or friend lol

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I did a search for Airspace and came across this!! Exactly what I was looking for. So glad you wrote this! @anon2063420 I then proceeded to experiment and fly around LAX, LGB, ONT to see the green rings turn on and off (indicating when I was entering and exiting the airspaces through through the ceilings and floors) and see what altitudes they were compared to the Airports height above sea level.

I found that you take the Airports SFC level. KONT is at 911 feet. You then round that up to the next 100. Therefore “rounded up” SFC (KONT) = 1,000 Ft and the green will turn on as stated below:

Delta Airspace/Charlie & Bravo’s Smallest ring
Ceiling = SFC + 2,500 AGL
Green Ring Ligthts up = 1,000 + 2,500 ft = 3,500 MSL

Charlie’s Outer/Bravo’s Middle Ring
Ceiling = SFC + 4,000 AGL
Floor = SFC + 2,400 AGL
Ceiling Green Ring Lights up = 1,000 + 4,000 ft = 5,000 MSL
Floor Green Ring Lights up = 1,000 + 2,400 ft = 3,400 MSL

Bravo’s Outter Ring/Airspace
Ceiling = SFC = 8,000 AGL
Floor = SFC = 3,900 AGL
Ceiling Green Ring Lights up = 1,000 + 8,000 ft = 9,000 MSL
Floor Green Ring Lights up = 1,000 + 3,900 ft = 4,900 MSL

This was consistent with the three Class Bravo Airports I experimented with as well as a couple Charlie and Delta Airports in the surrounding area. So one thing I found, It is AGL, not MSL for the airspace altitudes. I literally would fly around and slowly ascend and decend to find the MSL the Green Rings would turn on and off at. I know, I have too much time on my hands, but when I want to learn about a topic, I go right for it. Also what I found was that you do have to round the Airports Height above sea level to the next 100 increment. Then you add the digits I provided above to find out exactly where the ceiling or floor is for the airspace of the airport, and specifically which ring (Outter, Middle, Inner).

I don’t know how useful his is, but it was nice to know the exacts MSL above airport numbers,

My one question is how does this relate to the Airspace of 5000’ for all airports in IF. Why do we not use the rings system for ATC and transitions? An ATC controller, I know doesn’t get that information, but they could calculate it so they have it in front of them when they are controlling.

Okay,I think I beat this one to death.



Potentially the rings are made available to IFATC, but I would not know since I am not one. I know that in general for the US the second tier has a 200KIAS limit unless an aircraft cannot operate in the clean configuration at 200KIAS. Usually then the aircraft requests a higher departure speed which ATC needs to approve. For some US airports like KTPA the aircraft speed restriction extends higher. For instance on the SID chart for KTPA the aircraft is actually limited on a few departure to a KIAS below 250 until they reach 8000’.

If the rings are available for IFATC it would be very helpful for them to use those limits on departure and arrival if the airspace is not too busy. ATC can override these limits for spacing but ideally ATC would want to stay as close to this uniform speed limit as possible, primarily for arrivals. That way all the APPR ATC has to do is to space them on ILS correctly and not need to worry about speed commands. Spacing would take into account a constant approaching aircraft’s speed and the expected landing aircraft’s landing speed, which usually falls into a certain range of speeds. Since all approaching aircraft’s speed on upwind, crosswind,downwind and base legs will be uniform. IF you look at STAR charts you can see that most approaches have a point where the KIAS is capped to 200 even outside of the second tier.