What is the VFR flight visibility minimum in Class G airspace when you are operating at or above 10000 feet MSL during the day?

Airspace appears complicated at first,  but remember that airspace is like a layered cake. Just unfortunately not as delicious, or edible in any form for that matter.   We’ll go ahead and start building our layered cake from the ground up, explaining each layer at a time!

Class Golf

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.  The reason we put that in bold is because it is likely to appear on your 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 airports is Class G airspace going up to 1,200′ agl, and then Class E airspace starting above that.  Airports that are non-towered but still somewhat busy will have Class G airspace extending upward to 699′ agl, and then Class E airspace over top starting at 700′ agl.  To see examples of this, check out the video above!

Class G Requirements:

• Uncontrolled, you do not need to contact ATC to enter or land in Class G airspace.
• There are no specific equipment requirements.
• Basic VFR minimums apply, which 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 below 10,000′ msl  but higher than 1,200′ above the surface (agl), are: 3sm visibility, 1,000′ above clouds, 500′ below clouds, and at least 2,000′ horizontal from clouds.
• VFR minimums above 10,000′ msl day or night, and more than 1,200′ agl: 5sm visibility, 1,000′ above clouds, 1,000′ below clouds, 1sm horizontal distance from clouds.

Class G Airspace and Mountainous Terrain:

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. In these areas, it is possible to be flying in mountainous terrain upwards of 10,000 AGL, but be less than 1,200 AGL from the surface. Keep in mind that by doing so, you’d be close to the surface of a mountain which doesn’t always end well for airplanes!

You don’t have to remember all of this!  Just remember “91.155” which is the section number in the FAR/AIM that contains the table below.  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!

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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.

In some areas, the base of Class E Airspace drops from 1,200′ AGL to 700′ AGL. These are typically airports that support instrument approach and departure procedures. As these airports tend to be busier than smaller airfields, Class Echo airspace has more stringent weather requirements as compared to Class Golf airspace. For even busier non-towered airports, it is not uncommon for Class Echo to extend all the way down to the surface.

The size of the airspace usually correlates with the runway length; the longer the runway, the larger and faster the aircraft operating on that runway can be. Terrain elevation is also taken into account when designing Class E airspace.

Echo airspace is controlled airspace but does not typically have an operating control tower associated with it.  Instead, Echo airspace is airspace that air traffic control 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.

Class E Airspace Requirements

• You do not need to be in contact with Air Traffic Control to enter Class Echo airspace.
• There are 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.

Victor Airways

• The “V” stands for “Victor airway”. These airways correspond with VOR station placement. Think of them as a direct highway in the sky from one VOR station to another.
• Victor airways extend from 1,200′ AGL up to but not including 18,000′ MSL.
• The width of Victor Airways is 4 NM per side, or 8 NM total.
• It is important to exercise caution on airways and near VORs as there may be an increase in traffic as compared to operating off the airway.

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(The “real” 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, takeoff, 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 practical 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 Standards:

• Dimensions are often 4nm radius (can vary, but a good rule of thumb is 4nm radius for the “circle” around the airport)
• The 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 the 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 anything else special 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 only can 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 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 same basic structure remains the same of 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.

Check out the video below to see the steps involved in departing a Class D airport.  Take notes on the steps from getting the ATIS, to contacting Ground, and eventually contacting the Tower to Takeoff!   note: this is a 360 video, you can use the controls in the upper left corner to pan around the cockpit.

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Above: How to fly into Class Charlie airspace from another airport.

Class C Airspace

Class C airspace is relatively straight forward.  Not only are the dimension of Class C airspace easy to understand, but it is also easy to enter.

Requirements to enter Class C Airspace:

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

Class C Airspace Standards:

• 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 near or the Class C airspace “rings”.

Class C Weather Requirements

• Class C requires 3SM visibility, 1000′ above clouds, 500′ below clouds, and 2000′ horizontal.
• Just remember “3 Cessna 152s”

The Upside-Down Wedding Cake

The concept behind this layering is that it allows aircraft to remain in Class Charlie airspace throughout the descent as they approach the airport. It provides protection for faster aircraft while allowing smaller aircraft to operate out of nearby airports by having a smaller surface footprint.

Although the Class C airspace dimensions discussed above are typical, the shape of the airspace can change to accommodate surrounding terrain; such as tall mountains.

 Below: How to depart a Class C airport and what steps you’ll need to take in contacting all the appropriate air traffic controllers:

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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 is 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 they 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 who’s 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.

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Class A airspace is a fairly straight forward type of airspace to understand, it covers the entire globe, from 18,000′ msl or FL180 (flight level 180) up to and including FL600 (or 60,000′ msl).

Requirements to fly in Class A Airspace:

• An altitude-encoding transponder
• An instrument rating and IFR flight plan
• An aircraft that is appropriately equipped for instrument flight
• DME for operating at and above FL240 (Distance Measuring Equipment, a fancy way of saying GPS or something that tells you how far you are from a VOR / navigational station).
• Set your Altimeter to 29.92″
• Effective January 1st, 2020 all aircraft must have ADS-B out transmitting (91.225)
• There is no minimum cloud clearance or visibility requirements in Class A airspace since all aircraft are operated under IFR

The airspace above Class A

Airspace above FL600 (60,000′ msl) reverts back to Class G (uncontrolled airspace).  While this may change in the future, 40 years ago when the airspace limit was set at 60,000′ there were few airplanes that could fly that high, and no one believed that was going to change for a very long time (there is very little air up that high).  Now in the age of commercial space travel, this is rapidly changing and we may see either a new class of airspace in the future or an extension to the vertical limits of the current Class A airspace.

Where is this airspace?

Class A airspace exists everywhere over the continental United States, most of Alaska, and the airspace up to 12nm offshore of the United States.  The is no Class A airspace over Hawaii.

Fun Fact:

Yes some rare aircraft can actually fly at 60,000′ and beyond.  How high can they go?  Well that’s classified, but here’s a fun story of a SR-71 Black Bird

Los Angeles Center reported receiving a request for clearance to FL 600 (60,000ft).

The incredulous controller, with some disdain in his voice, asked: “How do you plan to get up to 60,000 feet?”

The pilot (obviously a sled driver), responded: “We don’t plan to go up to it, we plan to come down to it…”