Airspace Review (Optional)

Class B, the busy stuff

To make sense of this complicated cake, let’s build it from the ground up!

At a Class B airport, you have Ground Control, just like you would at a Class C or Class D airport.  Ground control issues taxi clearances.

You have Tower Control, same as any other towered airport.  The tower will issue takeoff and landing clearances.

Just after takeoff, Tower will pass you over to Departure Control.  Departure control and Approach control are the exact same thing, we just call the ATC controller we are talking to Departure when we are taking off and leaving, and Approach when we are approaching the airport to land.  If you are intending to land at a Class B airport, you will probably start talking with Approach control a good 30-40 miles from the airport.

The Shape of the Cake

What’s all this talk about cake?  If it’s making you hungry, feel free to take a short break and go eat a slice of cake, if you don’t have any cake handy in the fridge right now, then stay seated with your seatbelt fastened and continue studying.

We often refer to the design and shape of Class B airspace as an “upside down wedding cake”.  The reason is the way Class B airspace is designed in layers that progressively get wider the higher up from the surface you go.  Of course at the surface and at the center of the “cake” you will find the primary Class B airport (and lots of people and planes there too!). The diagram below gives you a nice side view of what Class B airspace looks like from the side.

The shape of each Class B airport’s airspace is unique to that individual airport.  Experts get together and decide how many, and where the layers should be to best protect arrivals and departures at the busy Class B airport, all while keeping as much airspace free and open as possible to mitigate encroaching on any other airports or any other areas you want to fly in.  Often you will find the “layers” start and end along identifiable landmarks such as shorelines, interstates, or railroads, all to help VFR pilots have clear “boundary” lines of where than can and cannot go given the altitude they are flying at.  For example, look at the KTPA Class B airspace below and see how the boundary lines are drawn using the shoreline as a reference and the interstate as a reference for some of the layers.  Other boundary lines are simply based off of distance from the center of the Class B airport.

Note: Be careful not to confuse the light blue lines of victor airways with the light blue lines of Class B airspace boundaries.

The Rules:

A few random rules about Class B airspace you should REMEMBER:

• The top is between 7,000′-12,500′ msl
• Speed limit of 200knots IAS below a shelf or “floor” of Class B and also 200kts limit when flying through a VFR corridor
• Mode C veil is 30nm radius of the Class B airport (where you are required to have a mode C transponder regardless of altitude)
• Need a specific clearance to enter Class B airspace, not just two-way radio communication.

When Should I Ask to Enter?

Well if you plan to fly through Class B, C, or D airspace, it’s best to let the controller know as soon as practical where you are and what you plan to do (fly through their airspace en route to XYZ airport for example).  This means for us in GA airplanes contacting most controllers at least 10nm prior to entering the airspace is a good practice (although you do not legally have to contact them until just prior to entry).  You will probably get radio reception 30-50nm from the primary airport whose airspace you intend to fly into, so if you’ve got nothing else better going on in the cockpit you might as well give them a call once you hear that your radio is in range.

Hey Charlie, there’s some airspace up ahead

Yes, there is, and it’s fairly straightforward and simple airspace at that.  Not only are the dimension of Class C airspace easy to understand, it is also easy to enter.

The requirements to enter:

• Transponder
• Two-way radio communication (usually by first calling approach control)
• Establish communication with approach control (or in rarer circumstances, call tower directly).

The Defaults:

• Inner ring is 5nm radius, from the surface to 1,200′ agl
• Outer ring is 10nm radius, from 1,200′ agl to 4,000′ agl (these are default values, actual floor and ceiling values will be given in MSL, i.e. The airport is at 500′ msl, the floor of the outer ring would be 1,700’msl (1,200′ agl) and 4,500′ msl for the ceiling of the outer ring).
• Class C airports typically have some airline traffic, but maybe only 20-30 flights per day.
• They will have Ground Control, Tower, and Approach Control.
• Approach Control typically controls an area 20-30 miles from the airport, yet you only LEGALLY need to talk to them if you are entering into Class C airspace.  It is still a good idea to contact them even if you are just flying by or near the Class C airspace “rings”.

 

You might be wondering where Class A airspace comes into play in all of this?  Class A airspace is a single layer that covers the entire globe from FL180 (18,000′ msl) to FL600 (60,000′ msl).  It is not associated with any particular airport.  We’ll talk about it more in the next TOPIC.

What happens around these towered airports when my radio fails?

Well, that’s a great question….   Especially since we just finished teaching you about how to contact a Class D airport tower and are about to talk about contacting a Class C airport tower.  So we actually have a way to handle this when you are flying and for whatever reason, you lose communication with the tower.  These same procedures are used by pilots who don’t even have radios installed in their airplanes and cannot communicate with the tower and deaf pilots who are landing at a towered airport too!

How ATC will communicate with you is via “LIGHT GUN SIGNALS” or basically shining a bright light at you from the control tower cab aimed right at your airplane.  The color and sequence of the light tell you what to do, and the signals mean slightly different things if you are on the ground or in the air.  Check out the diagram below and even reference our article on RADIO FAILURES HERE.

What do you do when you have comm problems?

Well, the simplest answer is land at a non-towered airport if you are near one, and the second simplest answer is land at a towered airport if you are already in their airspace and approaching to land or just flying laps in the traffic pattern.  You might also consider some troubleshooting tips listed below:

• Check your headset plugs (push them in all the way or maybe even wiggle them out a little to make the right contact in the socket)
• Try swapping headsets with a passenger if theirs is working and they hear ATC
• Check your radio volume
• Check the volume on your headset
• Check the audio panel is set so you hear your comm radio and that it is not selected to another audio source
• Check the frequency again, and consider going back to another frequency of a previous controller to have them give you an alternative frequency to use to contact the tower
• Try using frequency 121.5 if all else fails to establish contact with ATC or another aircraft
• Pick up your cell phone and call Flight Service and ask them to forward you directly to the tower cab to talk to them and get instructions and a landing clearance
• Ensure you don’t have a “stuck mic” or that the transmit button is not stuck down….that would prevent you from hearing anyone else but everyone else will hear every word you say!!! (careful what ya say!)

The real “Controlled” Controlled Airspace

Class D airspace is controlled and also has a control tower for the corresponding airport that will issue clearances to aircraft to taxi, take off, and land.

The difference between a Class D airport and other airports is that it may be just slightly busy enough to warrant having a control tower at the field, compared to less busy airports that are in Class G or Class E airspace.  Many Class D airports also only have part-time control towers that close after a certain time.  When the tower closes, the airport stays open, however, the type of airspace will change from Class D to Class E or Class G (which type it reverts to will be denoted in the Chart Supplement, formerly referred to as the AFD).

Class D airspace may have more than one airport inside of it.  The airport basically in the middle of the Class D ring is referred to as the “primary” airport within the airspace, and it is the airport that has the control tower located on the field.  You can actually take off from an airport that lies within Class D airspace without getting a takeoff clearance, you simply contact the tower at the primary airport AS SOON AS PRACTICAL after takeoff to let them know you are in their airspace now.  The reason they let you do this is because VHF aircraft radios transmit line of sight, and you may not be able to make contact with the control tower until after you are already airborne.  An example of an airport lying within Class D airspace is below:

 

Here you can see Belleville (43G) is inside of the YIP Class D airspace.  It is a small grass strip denoted by the open magenta circle, and although it is nearly outside of the Class D airspace, you will need to contact the tower at YIP as soon as practicable after takeoff and also when coming back into the Class D airspace to land back at 43G.

 

There are several “defaults” associated with Class D airspace that can be good to remember.

Class D Defaults:

• Dimensions are often 4nm radius (can vary, but a good rule of thumb is 4nm radius for the “circle” around the airport)
• Standard ceiling of the airspace is 2,500agl (it can be less sometimes when there is other “more important” airspace on top of the Class D Airspace
• You must establish “two-way radio communication” with the control tower for the Class D airspace to be “cleared into the airspace”.  You do not need to hear specific words “cleared into class D airspace” just communication with the Tower where they reply to you with your call-sign and do not tell you to stay out of the airspace.
• Equipment requirements:
  • All you need is a two-way radio.  It can even just be battery powered if you are flying a super old airplane without electronics.  You do not need any other special equipment to go into Class D airspace.
• Visibility requirements:
  • 3sm Visibility
  • 500′ below clouds, 2,000′ horizontal clearance from clouds, 1,000′ above clouds
  • You can request special VFR that would give you reduced minimums down to
    • 1sm visibility and just remaining “clear of clouds” (don’t fly through the clouds)
    • Special VFR can only be requested during the day, unless you are instrument rated and the airplane is also instrument equipped, then it can be requested at night too (not like anyone would reasonably want to fly in such poor conditions anyway, but hey, there’s a procedure that allows for it).

Here is an example of other “more important” airspace overlying the Class D airspace:

 

Here the Class D airspace around Page (FMY) goes up to 1,200′ msl and then the Class C airspace from Southwest Florida International (RSW) takes over and goes from 1,200′ msl to 4,000′ msl.

 

Flying into Class D Airspace

Check out this video below as an example of what it looks like to depart from a non-towered airport in Class G airspace and fly to and land at a towered airport in Class D airspace. Notice how the radio calls are different, but the basic structure remains the same: who you are calling, who you are, where you are, and what you want to do.    Note: this is a 360 video, you can use the controls in the upper left corner to pan around the cockpit.

The Everywhere Airspace

Echo airspace is the most common type of airspace you will encounter, no matter where it is you fly in the country.  You will find Echo airspace below 18.000′ msl everywhere that either Class B, C, D, or G airspace does not occupy.

Echo airspace is controlled airspace but does not typically have an operating control tower associated with it.  Instead, Echo airspace is airspace that ATC has control over usually via Radar coverage, and can issue clearances for pilots to go into the Echo airspace who are flying under IFR (instrument flight rules) or flying under Special VFR.  When you are flying under VFR (Visual Flight Rules), which you will be flying under 99.9% of the time as a private pilot, you do not need a clearance to enter into Class E airspace.

Requirements

• No specific equipment requirements
• Basic VFR minimums are 3sm visibility, 500′ below clouds, 1,000′ above clouds, 2,000′ horizontal from clouds.  When you are flying above 10,000′ msl the MINIMUMS BECOME: 5SM VISIBILITY, 1,000′ BELOW CLOUDS, 1,000′ ABOVE CLOUDS, 1SM HORIZONTAL FROM CLOUDS.
• Again, don’t sweat every detail of the VFR minimums, just REMEMBER the numbers 91.155 (that’s where you look it up in the FAR/AIM during your checkride).
• Remember 3-152’s  or Three – One Fifty Two’s (like 3 Cessna’s)  3-152s stands for 3sm, 1,000′ above, 500′ below, 2,000′ Horizontal.

Gee, I see lots of Airspace!

Yes, I bet you do.  It’s simpler than you think however.  Remember that airspace comes in layers, we’ll go ahead and start building it from the ground up explaining each layer one at a time.

Class Gulf

When it comes to Class G, think “G” for Ground.  Class G airspace will always start at the ground AND GO UP TO 14,500′ msl as a maximum.  Now that is in CAPS there because they like to ask you that on a written exam, in all reality, Class G airspace always ends well before 14,500′ msl due to another layer of airspace being on top of it.  In most cases, the airspace overlying Class G is Class E airspace.

Thus: the most common thing you will find in the space between all the airports is Class G airspace going up to 1,200′ agl, and then Class E airspace starting above that.  Near airports that are non-towered, yet still a little busy, you will find that the Class G airspace only goes up to 699′ agl, and the Class E airspace over top of and near the airport starts at 700′ agl.  To see examples of this, check out the video above!

Requirements:

• Uncontrolled, do not need to contact ATC to fly in
• No specific equipment requirements
• Basic VFR minimums are 1sm visibility and Clear of Clouds (don’t fly your airplane into a cloud or let it touch a cloud)
  • These minimums cover most Class G airspace, but are only valid during the daytime when you are within 1,200′ agl of the surface.
• VFR minimums at night anywhere below 10,000′ msl AND you are higher than 1,200′ above the surface, 3sm, 1,000′ above, 500′ below, 2,000′ horizontal
• VFR minimums above 10,000′ msl day or night, and more than 1,200′ agl: 5sm, 1,000′ above, 1,000′ below, 1sm horizontal

 

Clarification:

A lot of people wonder how can you be higher than 10,000′ msl (above sea level) and still within 1,200′ of the surface (only 1,200′ agl or less).  This really only applies out west in very mountainous terrain where the mountains are 10,000′ or more above sea level, then you could be that high, and still close to the surface (mind you that you’d be close to the surface of a mountain which doesn’t always end so well for airplanes, watch out!)

REMEMBER: You don’t have to remember all of this!  Just remember “91.155” that is the section number in the FAR/AIM that has the table below in it.  It is totally fair game to use that as a reference during your checkride.  No one expects you to remember ALL of this off the top of your head.  Just the basics will suffice!

Airspace	Flight visibility	Distance from clouds
Class A —————————–	Not Applicable ——————-	Not Applicable.
Class B —————————–	3 statute miles ——————–	Clear of Clouds.
Class C —————————–	3 statute miles ——————–	500 feet below. 1,000 feet above. 2,000 feet horizontal.
Class D —————————–	3 statute miles ———————	500 feet below. 1,000 feet above. 2,000 feet horizontal.
Class E: Less than 10,000 feet MSL.	3 statute miles ——————–	500 feet below. 1,000 feet above. 2,000 feet horizontal.
At or above 10,000 feet MSL.	5 statute miles ——————–	1,000 feet below. 1,000 feet above. 1 statute mile horizontal.
Class G: 1,200 feet or less above the surface (regardless of MSL altitude).
Day, except as provided in Sec. 91.155(b).	1 statute mile ———————-	Clear of clouds.
Night, except as provided in Sec. 91.155(b).	3 statute miles ——————–	500 feet below. 1,000 feet above. 2,000 feet horizontal.
More than 1,200 feet above the surface but less than 10,000 feet MSL
Day ———————————–	1 statute mile ———————-	500 feet below. 1,000 feet above. 2,000 feet horizontal.
Night ———————————	3 statute miles ——————–	500 feet below. 1,000 feet above. 2,000 feet horizontal.
More than 1,200 feet above the surface and at or above 10,000 feet MSL.	5 statute miles ——————–	1,000 feet below. 1,000 feet above. 1 statute mile horizontal.