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. https://en.wikipedia.org/wiki/Airspace_class_(United_States)?wprov=sfla1