Airport classifications

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flightmedic

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flightmedic
I hear a lot about class A airports or class C airports, etc. What do each of the classes mean? (i'm not a pilot)
 
flightmedic said:
I hear a lot about class A airports or class C airports, etc. What do each of the classes mean? (i'm not a pilot)
Click to expand...
The classification refers to the airspace around airports. In the US you will not see Class A airspace around and airport, you will in the UK though. In the US Class A airspace is only above above 18,000'MSL.

Most small airports will be in class G airspace, busier ones in class E, When a control tower is added to the the airport you will almost always find it surrounded by Class D. Then for the bigger airports with lots more traffic Class C and B will be the norm.

http://en.wikipedia.org/wiki/Airspace_class


Each of these types of airspace require certain equipment, certificate and communication prerequisites to enter them. As you progress in your training you will need to learn all of the differences.
 
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To provide a visual to what Scott said:

AlphabetAirspaceByFootFlyer.gif
 
Heh heh. The warning on the Wikipedia article is a crack-up...

"This article may be too technical for most readers to understand. Please help improve this article to make it understandable to non-experts, without removing the technical details. The talk page may contain suggestions. (August 2011)"
 
Nate, sorta like the eHow.com article on how to fly a C182?
 
Sorry for the late reply. Sometimes I think I should keep my mouth shut. Thanks for the help and I will study the responses until I understand.:redface:
 
flightmedic said:
Sorry for the late reply. Sometimes I think I should keep my mouth shut. Thanks for the help and I will study the responses until I understand.:redface:
Click to expand...

No one ever learned and fully-assimilated any complex topic by keeping their mouth shut. You're fine. Questions are good. The only thing you want to try to avoid is asking the same question twice. Take notes. :)
 
If you want to be good at your job, you need to know where to find the answers. Asking questions of subject matter experts (just ask 'em) is one of the many tools you have.
Ask away. Verify the results.
 
flightmedic said:
I hear a lot about class A airports or class C airports, etc. What do each of the classes mean? (i'm not a pilot)
Click to expand...

In addition to the other responses.. Some over-simplifications but give the gist (Nit pickers - this is written for non-pilots, from memory, and i'm not current)

Class G airspace- Uncontrolled airspace. No ATC function or separation is exercised in this area. Much of the US airspace close to the ground is class G (surface to 700 ft AGL (above ground level) near most BUT NOT ALL airports). The majority of the rest of the mid and eastern US is class G from surface to 1200 ft AGL. Out west in sparsely populated areas it can range up to 14,500 ft MSL (but if a mountain pops above that level, the 1200 ft AGL rule applies)

If you are an aeromedical provider, the vast majority of your operations may take place in this area, once you get out of the big city/vicinity of a big airport.

What this means is your pilot needs permission from nobody to go where he wants, but neither does anyone else operating in that area.

Class F - doesn't exist in the US. Its a form of controlled airspace with limited ATC function.

Class E airspace. This overlies class G airspace and goes up to 18000 feet in the continental US where Class A starts. This is a form of controlled airspace. ATC separates IFR traffic from other IFR traffic. VFR guys are responsible for separating themselves, and IFR is responsible for avoiding any VFR guys that ATC doesnt/cant see. Most of the altitude rules (eastbound IFR flies odd numbered thousands like 3,5,7,9 thousand feet, westbound flies even thousands like 4,6,8,10 thousand feet) help with separation. VFR's follow the same altitude separation rules but add 500 feet.. These rules apply only when 3000 feet AGL, but help keep head on traffic from merging. Probably not very applicable to Helicopter EMS, those guys tend to be below 2000 ft agl..

At airports with IFR approaches and surface weather observation, class E may go all the way to the surface in a circle approx 4-5 miles radius of the airport.

Class D airspace surrounds an airport, a control tower is provided, and the tower sequences aircraft to land, and provides separation between aircraft on the runway. This may not be an entirely nit-pick-proof description but covers most of the concept. You typically have to establish contact with the tower before entering their airspace.

There is a peculiar holdover that falls in between class D and class C.. Its called a TRSA.. Terminal Radar Service Area. Essentially a class D with an appoach control that operates on a voluntary basis but without enough traffic to make it mandatory participation like a class C.

Class C airspace surrounds a towered field that is busier. Airline or military operations may occur here (although they can happen at nearly any field, towered or not). There is a radar approach control that services the airspace, that identifies, directs and sequences inbound traffic to the primary airport centered in the airspace. There are again, details to what,where and whom is controlled may vary a bit, but to get to the primary airport you essentially have to contact ATC and coordinate your arrival. Many non-hub airline destinations are class C and Class D.

Class B airspace surrounds airports that are very large, with very heavy amounts of airliner/jet traffic and typically are airline hubs. The airspace resembles an inverted wedding cake, with 10, 20 and sometimes 30 mile radius rings around a defining point, usually the primary airport. They go from surface for the inner ring all the way up to 8-10,000 MSL. All traffic within the class B is controlled by ATC. They are responsible for keeping all aircraft separated from each other, including helicopters. There is radar approach service, and approach control takes departures from the tower, and sequences them into the enroute airspace (Center).

The 10,000 ft ceiling of most class B's is pertinent because of the speed limit imposed below that level. There is also a speed limit for aircraft operating BELOW the class B shelves, due to presumed congestion, and potential for head-on convergence - the area under the shelf is typically Class E above 700 feet AGL, but may contain other class C, Class D and Class E-to-surface areas. Below 700 feet is class G. Your aeromedical guys may operate in this area quite a bit, even when the big iron is doing their thing 2000 feet above you.

There is a transponder requirement (mode c altitude readout) when within 30 nm of the center of the class B, to allow airliner and ATC equipment to know your altitude for separation purposes. The 10,000 ft speed limitation rule is also the reason that visibility/cloud clearance requirements increase above this level - the planes are allowed to move faster, so a VFR plane needs more time/distance to react to an IFR plane popping out of a cloud on a converging course... The east/west even/odd rules apply up above 10,000 feet too.

Class A (airspace): In the US is essentially IFR only, and is above 18,000 up to 60,000 feet. ATC is responsible for separation - their job to keep you from hitting other people.

Hope this sheds a little bit of light
 
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Doggtyred, (Which is how I feel right now)

Thanks for the class by class description which helps me interpret the chart above. I appreciate the time it took you to write that lengthy description. I appreciate all the responses and now I have several things to read and study.

Thanks to all the respondents.

Roy
 
Or when you have a question, you could just call your friend and ask him to explain it to you.

Just messing with ya, saw your post and thought I would jump in and say hi.

Mike in a cold and snowy NJ
 
You know I don't want to take time out of your dwindling flying season. How did you fair in that light dusting you had up there. My sister is still out of power.
 
I wouldn't call 8-10 inches of snow a dusting. I had about 3 at my house, no power problems here. My girlfriends house was without power for about 4 days, she brought her birds to my house and stayed here until the power came back on.

Hope you are doing well in sunny Fla.
Mike G
 
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