This post is for informational purposes only. You should ALWAYS review codes and regulations prior to flying.
In the United States, we have 6 designated airspace’s as defined by the Federal Aviation Administration (FAA). They are: A-Alpha, B-Bravo, C-Charlie, D-Delta, E-Echo, G-golf. Each airspace serves a different purpose.
Image taken from The Federal Aviation Administration
Alpha Airspace, as defined by the FAA, is airspace that starts at 18,000 ft. MSL (Mean Sea Level), and extends upwards to FL 600.
FL simply stands for Flight Level; always add 2 zeros to the end of a FL to get the altitude in feet. So, FL 600 is 60,000 MSL.
The FAA further defines Alpha Airspace as overlying the waters within 12 nautical miles of the coast of the 48 contiguous states and Alaska.
All aircraft flying in this airspace are under IFR (Instrument Flight Rules). That is a requirement. No VFR (Visual Flight Rules) flights are allowed.
Bravo Airspace, as defined by the FAA, is airspace that in general, is the airspace from the surface up to 10,000 ft MSL, and surrounds the nations busiest airports.
By “busiest airports”, they mean airports such as Chicago O’Hare, or Miami International. Being that I am from Colorado, our Class Bravo Airport is Denver International (KDEN). These airports are very busy, and handle a lot of air traffic on a daily basis.
The following are REQUIRED when attempting to fly through Bravo Airspace:
- Aircraft must have operable two-way radio capable of communicating with ATC (Air Traffic Control) on the Bravo frequencies
- Aircraft must be equipped with an operable radar beacon transponder with automatic altitude reporting equipment
- There are currently 12 Bravo airports where the pilot in command (PIC) must hold, at minimum, a Private Pilot License
- From the surface to 10,000 ft MSL, and within 30 nautical miles of a Class Bravo Airport, the aircraft is required to have a Mode C transponder with altitude reporting
Bravo airspace resembles an upside down wedding cake, with at least 3 layers. Each layer being a different diameter. They are specifically tailored to the airport they serve.
Class Bravo Airspace is no joke. Do not enter this airspace without the specific direction to do so from the Bravo airport’s ATC. They will specifically clear you to enter their airspace.
As defined by the FAA, Charlie Airspace is generally the airspace from the surface up to 4,000 ft above the airports elevation. Notice this time it says “above the airports elevation” instead of MSL. That is very important to note. For one, in Colorado, if you attempted to fly at 4,000 ft MSL in the Denver Metro Area, I’m afraid your plane would be buried under about 1,000 ft of dirt and rock.
Charlie Airports, in general, have the following:
- Have an operational control tower
- They are serviced by a radar approach control
- These airports have a certain number of IFR operations or passenger enplanements
Basically, passenger enplanements and IFR operations determine how busy the airport is. Typically, and very generally speaking, Class Charlie airports are usually regional airports like Colorado Springs, or Akron.
If you will be entering Charlie Airspace, you must establish two-way communication with the airports control tower. Note that this is different than Bravo. In Bravo you MUST be cleared to enter, and in Charlie, you just have to make sure they hear you and you hear them. What I mean is; if you call into a Charlie tower with “Colorado Springs Tower, Skyhawk 12345, 15 miles northeast, inbound for full stop with Zulu”, and they don’t respond…then you have not established two-way communication and therefor cannot enter their airspace.
Similar to Bravo Airspace, Charlie Airspace resembles an upside down wedding cake, but with just 2 layers. These airspace’s are also specifically tailored to the airport they serve.
The airport I use the most, the one I fly in and out of a lot, is a Delta Airport.
The airspace surrounding these airports extend from the surface, up to 2,500 ft above the airports elevation. Again, NOT MSL.
Two-way radio communications, just like in Charlie, must be established prior to entering Delta Airspace.
Let’s assume you have radioed into the Delta tower, and they respond with “Aircraft ABC, standby”, then two-way radio communication has been established, and you may now enter the airspace.
Generally speaking, if the airspace is NOT A,B,C or D airspace, and if it is controlled, then it is Echo Airspace. In this airspace, there are no pilot certification requirements, or equipment requirements.
Golf is simply uncontrolled airspace. A class Delta airport, with a control tower, can revert to either class Echo or class Golf if the control tower does not operate during certain hours.
VFR Flight Requirements
VFR stands for Visual Flight Rules. When flying VFR through any airspace there are minimums that you must comply with per the FAA. If these minimums are below the standard for VFR flight, then you must fly IFR.
The table below states all minimums that are required:
Image/table taken from The Federal Aviation Administration
The airspace’s, and the minimum requirements for VFR, are an important piece in any flight. If ignored, it is possible that you will be punished by the FAA for disobeying the airspace and minimum flight rules.
Don’t stress, there are many many tools you can bring with you in flight to ensure you do not bust any airspace unintentionally. But, for best practice, review the airspace’s that you might encounter on your flight, prior to takeoff. This is all part of pre-flight preparation.