Learn to Fly in New York - The National Airpsace System

The National Airspace System

Introduction

What is airspace? We can imagine that the sky that we fly in is a big house. A house with many different rooms. Some rooms you can just walk right in. Sometimes you need to knock and get permission before you enter a room. Other times you can walk right in, but you need to take you shoes off so you dont ruin the carpet. Some rooms require that you both knock AND take off your shoes. Get the idea, huh? Wondering what the house with carpets and knocking has to do with Airspace, right? Well, the skies that we fly in are split into different airspaces. These airspaces help regulate the flow of traffic and provide a safe enviroment. Some types of airspace can be flown in freely, some require permission to enter and some have special rules that you must follow before and when you enter. Dont worry, you can keep your shoes on.

In this briefing you will be introduced to the different kinds of airspace. You will learn the dimensions, rules and weather minimums. In addition you will also learn how to recognize these airspaces on the VFR sectional chart.
Lets get started.

Airspace

There are two categories of airspace: Regulatory and Non-Regulatory.
Within these two categories are 4 kinds of airspace:
1) Controlled
2) Uncontrolled
3) Special Use
4) Other airspace

Regulatory airspace includes the following kinds of airspace:
1) Class A, B, C, D and E airspaces
2) Restricted Airspace
3) Prohibited Airspace

Non-Regulatory airspace includes:
1) Military Operations Areas (MOA)
2) Alert Areas
3) Controlled Firing Areas

The categories and types of airspace are dictated by a few factors such as:
The complexity or density of aircraft movements;
The nature of the operations conducted within that airspace;
The level of safety required; and
The national and public interest

Controlled Airspace

Controlled Airspace is a generic term that covers the different classification of airspace and defined dimensions within which air traffic control service is provided to flight conducted under Instrument Flight Rules (IFR) and to flights conducted under Visual Flight Rules (VFR) in accordance with the airspace classification.

As Pilot In Command (PIC) it is your responsibility to insure that you comply with all equipment and radio communication requirements prior to entering Class B, C or D Airspace. What do you have to do and what equipment do you need? Read on and find out.

Class A

Class A airspace generally extends from 18,000' Mean Sea Level (MSL) up to and including FL600 (60,000'). This includes the airspace overlying the waters within 12 Nautical Miles (NM) of the coast of the 48 contiguous states and Alaska. Unless otherwise authorized, all operation in Class A airspace will be conducted under IFR.

Class B

Class B airspace is generally the airspace from the surface to 10,000' MSL surrounding the nation's busiest airports.
The configuration of the Class B airspace is individually tailored to the specific needs of the airport in question. It comprises of a surface area and two or more layers. It kind of looks like a wedding cake standing on its head, doesn't it? Prior to entering Class B airspace you need to make sure that your aircraft is equipped with an Altitude encoding transponder, otherwise called a Mode C Transponder. After making sure that you have that, you need to establish Two-Way radio communications with the controllers. Once you have that, you need the controllers permission to enter the Class B airspace. Once you have those three things, you are golden. Don't worry, we will review those requirements later. In addition to that, extending 30NM from the center of the primary airport in the Class B is a Mode C veil. Before you can operate in this area you need to have and operate a Mode C transponder.
The weather minimums for VFR flight within Class B airspace are: 1) 3 Statute miles visibility 2) Keep clear of any clouds
So now that you know what it is, how can you find it on your map? To the right you will see a picture of the Boston Logan International Airport's Class B airspace as its depicted on the VFR sectional chart. Lets start from outside in. If you look at the very top corners, you will see a thin purple line. This line represents the Mode C Veil, indicating that you need an operable Mode C transponder to fly within the enclosed area. Moving closer towards the center, we reach a solid blue ring. This is the limit of the upper shelf of the Class B. On the inner part of the circle we can see what looks like a fraction: 70/30. This indicates the vertical limits of that specific shelf of the airspace (they just drop the last two zeros from the number). The number on the bottom indicates the floor of the shelf, and the top number represents the top of the airspace. So in this case, the floor of the Class B is at 3000 feet MSL an the top is at 7000 feet MSL. Moving closer to the airport itself we come to another blue line indicating another shelf in the Class B airspace. This one has a fraction of 70/20. So now the floor of the Class B has lowered itself to begin at 2000 feet MSL.
As we move ever further in towards the airport we encounter another blue line. This line has a fraction of 70/SFC. This means that the floor of the Class B starts at the Surface until 7000 feet MSL. Keep in mind, you are allowed to fly below the shelfs of the Class B and you will NOT be in Class B airspace. For example, if you are flying at an altitude of 1500' MSL within the area marked with 70/30, you are not in the Class B airspace because it only begins at 3000' MSL.

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Class C

Class C airspace is generally the airspace from the surface to 4000' AGL surrounding those airports with an operational control tower, that are serviced by a radar approach control, and with a certain number of IFR operations and passenger flights.
The configuration of the Class C airspace generally includes a 5NM radius surface area that extends from the airport elevation up to 4000' Above Ground Level. In addition there is a 10NM radius area that extends from 1200' AGL up to 4000' AGL. Prior to entering Class C airspace you need to make sure that your aircraft is equipped with an Altitude encoding transponder, otherwise called a Mode C Transponder. After making sure that you have that, you need to establish Two-Way radio communications with the controllers. Once you have those two things, you can enter the Class C airspace. Also, if you overfly the Class C airspace you require a Mode C transponder. Don't worry, we will review those requirements later. In addition to that, extending 20NM from the center of the primary airport in the Class C is a Outer Area extending from the surface up to 4000' AGL. You do not need any special equipment and you do not need to establish two-way radio communications in order to operate in the outer area.
The weather minimums for VFR flight within Class C airspace are: 1) 3 Statute Miles Visibility 2) Maintain 500 feet below clouds 3) Maintain 1000 feet above clouds 4) Maintain 2000 feet horizontal distance from clouds.
So now that you know what it is, how can you find it on your map? To the right you will see a picture of the Richmond International Airport's Class C airspace as its depicted on the VFR sectional chart. Lets start from outside in. You will notice two purple circles. The outer circle depicts the limits of the 10NM radius and we can see from the fraction of 42/14 that the floor of the shelf is 1400' MSL and the tops of the Class C airspace is 4200' MSL. Moving closer to the airport itself we come to another purple line indicating the surface area of the Class C airspace. This one has a fraction of 42/SFC. So we know that the Class C airspace here begins at the surface and extends to 4200' MSL.

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Class D

Class D airspace generally extends from the surface up to 2500' AGL and has a 4NM radius from the primary airport. Class D airspace surrounds those airports with operating control towers. The configuration of the Class D airspace can be individually tailored to the specific needs of the airport in question. Prior to entering Class D airspace you need to establish Two-Way radio communications with the controller. Once you have that, you can freely enter the Class D airspace. Don't worry, we will review those requirements later.
The weather minimums for VFR flight within Class D airspace are: 1) 3 Statute Miles Visibility 2) Maintain 500 feet below clouds 3) Maintain 1000 feet above clouds 4) Maintain 2000 feet horizontal distance from clouds.
So now that you know what it is, how can you find it on your map? To the right you will see a picture of the Majors Airport Class D airspace as its depicted on the VFR sectional chart. The Class D is depicted but a segmented blue circle. These represent the horizontal boundaries of the airspace. Within the circle you can see the number 30 inside brackets [30] . This tells you the top of the airspace in thousands of feet MSL. [30] means that the top of the airspace is at 3000' MSL.

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Class E


Class E airspace is generally controlled airspace that is not designated as Class A, B, C, or Class D. Unlike other airspace, Class E has no defined vertical limits, except between 18,000' and FL600 (Class A airspace). Class E airspace extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace. There are no requirement for VFR pilots while flying in Class E airspace and you may enter and exit it as you please without speaking to a controller. However, while in Class E airspace you may ask for Flight Following services which would require you to make radio contact with the controlling facility for that area.
The VFR cloud clearance and visibility requirements for flight in Class E airspace are split into two. Those for flights below 10,000 MSL and those for flights above 10,000 MSL. For flights below 10,000 MSL: 1) 3 statute miles visibility 2) 500' below the clouds 3) 1000' above the clouds 4) 2000' horizontal distance from the clouds For flights above 10,000 MSL: 1) 5 statute miles visibility 2) 1000' below the clouds 3) 1000' above the clouds 4) 1 statute miles horizontal distance
So now that you know what it is, how can you find it on your map? To the right you will see a picture of the Class E airspace that surrounds the McGhee airport. The Class E airspace starts either at the surface or at the specified altitude. The faded purple line around McGhee airport indicates which altitude is the floor of the Class E airspace. Any area that is within the enclosed area created by the faded purple line, indicates that the floor of the Class E is at 700' AGL. Any area outside the faded purple line has the floor of Class E at 1200' AGL. Sometimes you will see a segmented purple line enclosing an area. Much like the segmented lines around a Class D. These enclosed areas indicate that Class E airspace starts from the surface.

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Class G

Class G airspace is also known as uncontrolled airspace and is the portion of airspace that has not been designated as Class A, B, C, D, or E airspace. Class G airspace extends from the surface to the base of the overlying Class E airspace. Although air traffic control has no authority or responsibility to control air traffic, pilots should remember that there are still VFR minimums which apply to Class G airspace.

Ok, we just had a lot of info to take in. Class A, B, C, D, E, for some reason we skip F and then finally Class G. Each airspace has its own rules to enter and its own Minimum operation from clouds and such. Lets put it all into a chart to make it more organized.

Airspace	Equip.	Communications	Vis.	Cloud Clearance
A	Mode C	IFR Clearance	-	-

B	Mode C	ATC Clearance, 2 way radio communications	3SM	Clear Of Clouds

C	Mode C	2 way radio communications	3SM	500 Below 1000 Above 2000 Horizontal

D	-	2 way radio communications	3SM	500 Below 1000 Above 2000 Horizontal
E			Above 10,000 MSL
	-	-	5SM	1000 Below 1000 Above 1SM Horizontal

			Below 10,000 MSL
	-	-	3SM	500 Below 1000 Above 2000 Horizontal
G
			DAY 1200' AGL or below
	-	-	1SM	Clear Of Clouds

			Night 1200' AGL or below
	-	-	3SM	500 Below 1000 Above 2000 Horizontal

		Day: More than 1200' AGL but less than 10,000 MSL
			1SM	500 Below 1000 Above 2000 Horizontal

		Night: More than 1200' AGL but less than 10,000 MSL
			3SM	500 Below 1000 Above 2000 Horizontal

		More than 1200' AGL and at or more than 10,000' MSL
			5SM	1000' Below 1000' Above 1SM Horizontal

Special Use Airspace

Special use airspace is put into place where activities must be confined due to their nature. In special use airspace, limitations may be placed on those aircraft who are not participating in the special activites. Special use airspace includes:

1) Prohibited Areas
2) Restricted Areas
3) Warning Areas
4) Alert Areas
5) Military Operation Areas
6) Controlled Firing Areas
7) The Washington DC Air Defense Identification Zone (ADIZ) and Flight Restricted Zone (FRZ)

Alert, Prohibited and Restricted Areas

An Alert area is airspace that was designated to advise pilots that a large amount of pilot training or unusal aerial activity take place in that area. You do NOT need any special permission to fly within an Alert area, just be more ALERT to hazards and traffic when passing through one.

A Prohibited area is established for for security or other reasons that have to do with national welfare.
Aircraft may not enter a Prohibited Area unless prior permission has been received by the Using Agency.

Restricted Areas indicate the exsistance of unusual, often invisible hazards to aircraft such as artillery, aerial gunnery, or guided missles.
Aircraft may not enter restricted airspace unless permission has been obtained from the controlling agency.

Alert, Prohibited and Restricted airspace are listed on the VFR sectional chart . They are indicated by a ticked blue line with the prefix of either "A" for Alert, "P" for Prohibited or "R" for Restricted, then the number of the Secial airspace.

In the example on the right, we are looking at Restricted Area - 2906.

To find out more details about the airspace, we can reffer to the bottom of the sectional chart where we will find a listing of all the special use airspace. (Below)

We can then see that R-2906 is from the surface up to and including 14,000 MSL, it is operative intermittently between 0500- 0100 Zulu time, and the controlling agency is Jacksonville TRACON.

Military Operations Areas, Warning Areas and Controlled Firing Areas

Military Operations Areas or MOA for short, are airspace that were created to seperate certain military training activities with IFR traffic. You do NOT need any special permission to fly through an MOA; However, if you do choose to fly through an MOA, be on the look out training flights that may include acrobatic flight and other abrupt maneuvers. MOA's are depicted on VFR Sectional charts but a magenta ticked line with the letters MOA and then the name of the airspace. You can find out more about that specific airspace by reffering to the bottom of the sectional, like we did for Prohibited and Restricted airspace.

Warning Areas consist of airspace which may contain hazards to aircraft that are not participating in activities that are very similar to those within a Restricted airspace. The purpose of this airspace is just as its name implies, to warn the pilot of such activities. You do NOT need special permission to enter a Warning Area. A Warning Area may be located over domestic or international waters or both and are clearly marked on the VFR sectional chart.

Controlled Firing Areas contain activities, which, if not conducted in a controlled environment, could be hazardous to non participating aircraft. The difference between a Controlled Firing Area and other Special Use Airspace is that all operations must be suspended the moment that a spotter aircraft, ground radar or any other surveillance system recognizes a non-participating aircraft enter the area.