1. Airspace

2. Overview of Airspace
The following are general descriptions and dimensions. The markings are standardized but the size and shape of the airspace is varied according to the need for that particular area.
Airspace dimensions are as depicted on the current sectional, world and/or terminal charts.
Overview of airspace:
The following are general descriptions and dimensions.
The markings are standardized but the size and shape of the airspace is varied according to the need for that particular area.
Airspace dimensions are as depicted on the current sectional, world and/or terminal charts.

3. Airspace at a Glance 60,000 ft msl 18,000 ft msl clearance trans/alt
Class A
No VFR
Class E
no radio requirement/no communication requirements
no transponder requirements except above 10,000 ft msl
E 14,500 ft msl
Class G uncontrolled/ no requirements for radio or transponder except above 10,000 ft msl
E 1,200 ft agl
E 700 ft agl
Class B
Class C
E Surface
E Surface
Class D
Class B
clearance
trans/alt
Class C
2 way contact
trans/alt
Class D
2 way contact

4. No VFR flight is allowed An IFR flight plan is required
60,000 ft msl (FL60)
18,000 ft msl
Class A Airspace exists over the entire country at 18,000 ft msl up to 60,000 ft msl (the military takes over at the higher altitudes)
No VFR flight is allowed
An IFR flight plan is required
A transponder with altitude encoding is required
A 2 way radio and an IFR clearance are required
Class A Airspace is not depicted on charts
Class A airspace exists over the entire country at 18,000 feet MSL up to 60,000 feet MSL (the military takes over at the higher altitudes).
No VFR flight is allowed.
An IFR flight plan is required.
A transponder with altitude encoding is required.
A two-way radio and an IFR clearance is required.
Class A airspace is not depicted on charts.

5. Class B Airspace
Pilot must have at least a Private Pilot Rating, or Student Pilot with an endorsement for that particular Class B Airspace
Requirements: 2 way radio, transponder with altitude encoding and a clearance before entering
When inbound, first contact is made with approach control, Max speed 250
Airspace is served by radar from primary airport
30 nm
radius
10,000 ft
msl
height

6. Seattle Class B Airspace as depicted on sectional
Requirements to Enter
Transponder/alt encoding
clearance/2 way radio
private/student B endorsed
or higher
Note;
Transponder required in,
below and above
within 30 nm mode C veil
Solid blue lines indicate
Class B Airspace
Mode C Veil
solid magenta line
Maximum Elevation Figure
highest obstacle plus 300 ft

7. Top number
indicates 10,000 ft msl
for Class B top
Airport Information
Bottom number
indicates 6,000 ft msl
for Class B base

8. Class C Airspace
Requirements; 2 way radio, transponder with altitude encoding and established radio contact prior to entry into middle or inner area
Outer area doesn’t require radio or transponder but the transponder is required above Class C Airspace (radar service is available in outer area not depicted on sectional chart but appears here in darker blue)
Class C primary airport has radar and therefore initial contact should be made with approach control prior to entry
Middle Area 10 nm radius
Outer Area
20 nm radius
4,000 ft agl
Inner Area
5 nm radius
1,200 ft agl

9. Class C Airspace
The following services are provided within Class C airspace:
Sequencing of all arriving aircraft to the primary airport
Standard IFR separation between IFR aircraft
Between IFR and VFR aircraft – traffic advisories and conflict resolution
Between VFR aircraft – traffic advisories and as appropriate, safety alerts
Middle Area 10 nm radius
Outer Area
20 nm radius
4,000 ft agl
Inner Area
5 nm radius
1,200 ft agl

10. Inner Area Middle Area This portion of Class C Airspace
has a height of 4,000 ft msl
and a base of 2,000 ft msl
This portion of Class C Airspace
has a height of 4,000 ft msl
and a base of 1,300 ft msl
Inner Area
Class C airspace is depicted on sectional charts as solid magenta lines.
The airspace is usually constructed in a two tier pattern with the center portion extending from the surface to a specified altitude (usually 4,000 feet) and extending about 4-6 nautical miles outward from the primary airport.
The portion on the left side of the Class C airspace has a height of 4,000 feet MSL and a base of 1,300 feet MSL.
Near the top area of Class C airspace depicted on the chart has a height of 4,000 feet MSL and a base of 2,000 feet MSL.
4,000 feet MSL height down to the surface within 4 nautical miles of the primary airport is depicted as 40/SFC.
4,000 ft msl height
down to surface
Middle Area
Solid magenta lines indicate Class C Airspace

11. Class D Airspace
Requirements; 2 way radio, establish 2 way radio contact with tower prior to entry
No transponder requirements
Class D Airspace does not have radar at primary airport therefore there is no approach control
Max speed 200 kias w/in 4nm
Generally reverts to Class E when the tower closes
Class D Airspace:
Requirements; two-way radio, establish two-way radio contact with tower prior to entry.
No transponder requirements.
Class D Airspace does not have radar at primary airport therefore there is no approach control.
4 nm radius
2,500 ft height agl

12. Dashed blue line indicates Class D Airspace
Requirements;
2 way radio,
contact tower
prior to entry
Note;
No primary radar
Dashed blue line indicates
Class D Airspace
Segmented Box
indicates top of Class D
- Here 2,700 ft msl
Class D airspace is depicted as a dashed blue line on VFR sectional charts with airspace extending usually about 4 nautical miles away from the primary class D airport.
The dashed lines indicate that the airspace extends down to the surface up to a prescribed altitude which is located within the blue dashed brackets.
In this instance the airspace is from the surface up to 2,700 feet.

13. Class D Airspace surface to 4,000 ft msl Here Class D Airspace
This is an example of class D airspace extending from the surface up to 4,000 feet. We know the airspace is down to the surface because of the presence of a dashed line marking the outer boundary of the airspace.
The shape of this airspace is unique because of the notch that protrudes from the left side.
The purpose of the notch is to extend the boundary of the airspace to facilitate an instrument approach at that airport.
We can see that the notch lines up with one of the runways at the airport by looking at the runway orientation inside of the blue circle.
Class D Airspace
surface to 4,000 ft msl
Here Class D Airspace
has an extension

14. Class E Airspace
By definition is controlled airspace which is not A, B, C or D
No transponder or radio is required below 10,000 ft msl but a transponder is required above 10,000 ft msl
No communication is required
Class E Airspace extends upwards from it’s designated base until encountering other controlled airspace with greater restrictions and/ or requirements

15. Class E at the surface up with dashed magenta line
Class E Airspace
Class A Airspace beginning18,000 ft msl
Class E at 14,500 msl if no other indications, this has no color coding on charts
Class E airspace
This chart shows the vertical extension of airspace and the possibilities that exist. Starting at the right side, class E airspace is notated with a dashed magenta line and shown from the surface up.
Next to that is an example of Class E airspace with a hazed magenta line which indicates class E airspace starting at 700 feet.
Adjacent to that is a blue hazed line that signifies class E airspace from 1,200 feet AGL up.
If there are no other indications of airspace on a chart, Class E airspace is automatically assumed at 14,500 feet MSL to Flight Level 180.
Upon reaching 18,000 feet, class A airspace begins and extends upward to Flight level 600.
Class G Airspace
Class E at the surface up
with dashed magenta line
Class E at 1,200 ft agl up
with haze blue line
Class E at 700 ft agl up
with haze magenta line

16. starting at the surface
Indicates Class E
starting at the surface
upwards
Indicates Class E
starting at 1,200 ft agl
upwards
In some instances Class E airspace down to the surface is necessary as well as a Class E shelf where it begins at 700 feet.
This is necessary to facilitate ATC’s control of traffic on instrument approaches to an airport.
Class E from 1,200 feet AGL upwards is denoted on VFR sectional charts as a blue hazed line similar to the magenta that is used to denote Class E airspace from 700 feet AGL.
Indicates Class E
starting at 700 ft agl
upwards

17. Chain used to indicate Class E with
base in this case 8,200 ft msl upward
On a VFR sectional chart, Class E airspace in mountainous areas can be denoted by a chain pattern box with the altitude included within.
In this case Class E airspace begins at 8,200 feet MSL extending upward.

18. Victor Airways are Class E Airspace
8 nm wide (4 nm either side of center)
1,200 agl upwards
On a VFR sectional chart, Victor Airways are depicted as a hazy blue line with a V and designation number following it.
Class E airspace is 8NM wide (4NM either side of center of the victor airway) and extends upwards from 1,200 feet AGL.

19. Special Use Airspace Prohibited Areas (blue comb line)
Restricted Areas (blue comb line)
Warning Areas (blue comb line)
Alert Areas (blue comb line)
Military Operations Areas (MOA) (magenta comb line)
Special Use Airspace:
Prohibited Areas are denoted as a blue comb line.
Restricted Areas are denoted as a blue comb line.
Warning Areas are denoted as a blue comb line.
Alert Areas are also denoted as a blue comb line.
Military operations areas (MOA) are denoted as a magenta comb line.

20. Prohibited Areas These are established for national security
No flight operations are allowed within them
Prohibited Areas:
There are established for national security.
No flight operations are allowed within them.

21. Restricted Areas Flight operations are subject to limitations
There may exist hazards to aircraft as missile firing, artillery and other often invisible dangers associated with military training
Prior permission from controlling agency must be obtain before entering Restricted Areas
Restricted Areas:
Flight operations are subject to limitations.
There may exist hazards to aircraft as missile firing, artillery and other often invisible dangers associated with military training.
Prior permission from controlling agency must be obtained before entering Restricted Areas.

22. Warning Areas
These are the same as restricted areas in regards to hazards but are located over international waters
Technically the U.S. government cannot require that aircraft obtain permission prior to entry but since hazards may exist, it is standard operating procedure
Warning Areas:
These are the same as restricted areas in regards to hazards but are located over international waters.
Technically the U.S. government cannot require that aircraft obtain permission prior to entry but since hazards may exist, it is standard operating procedure.

23. Alert Areas
Indicates area to contain high volume pilot training or unusual type of aerial activity
Flight is not restricted but extreme caution should be exercised
Alert Areas:
Indicates area to contain high volume pilot training or unusual type of aerial activity.
Flight is not restricted but extreme caution should be exercised.

24. Military Operation Area (MOA)
Flight is not restricted
Area may contain military training activities
Although not required, contacting controlling agency is helpful prior to entry to help with collision avoidance while MOA is active
Military Operation Area (MOA):
Flight is not restricted.
Area may contain military training activities.
Although not required, contacting controlling agency is helpful prior to entry to help with collision avoidance while MOA is active.

25. Prohibited, Warning, Alert Areas and
Restricted Airspace indicated by blue comb line
and written indication of type, here Restricted
up to 20,000 ft msl
This is an example of a VFR sectional chart with a restricted area outlined with a military operations area.
The Restricted area is denoted by a blue comb line and the military operations area is denoted by a magenta comb line.
Military Operations Area
indicated by magenta comb line

26. Other Airspace Military Training Routes (MTR)
Air Defense Identification Zones (ADIZ)
Temporary Flight Restrictions (TFR)
Other Airspace:
Military Training Routes (MTR).
Air Defense Identification Zones (ADIZ).
Temporary Flight Restrictions (TFR).

27. Military Training Routes (MTR)
High volume/high speed (possibly in excess of 250 knots) military aircraft
IR indicates IFR training route
VR indicate VFR training route
If MTR has 3 numbers, it has portions above and sometimes below 1,500 ft agl
If MTR has 4 numbers, all portions should be below 1,500 ft agl
There are no restrictions on aircraft concerning communication or equipment
Military Training Routes (MTR):
High volume/high speed (possibly in excess of 250 knots) military aircraft.
IR indicates IFR training route.
VR indicates a VFR training route.
If MTR has 3 numbers, it has portions above and sometimes below 1,500 feet AGL.
If MTR has 4 numbers, all portions should be below 1,500 feet AGL.
There are no restrictions on aircraft concerning communication or equipment.

28. Military Training Routes IR indicates IFR, VR indicates VFR
3 numbers indicate surface up
4 indicates no segment above 1,500 ft agl
Sectional chart showing VFR and IFR military training routes.

29. Air Defense Identification Zone (ADIZ)
Aircraft entering U.S. airspace must be identified prior to entry
Enter w/in +5 Min of estimate and w/in 10 mi over land and 20 mi over water
Aircraft must file a flight plan (IFR or DVFR) prior to entry
You must have a transponder with altitude encoding
A 2 way radio to give periodic reports of position to ATC is required
Air Defense Identification Zone (ADIZ):
Aircraft entering U.S. airspace must be identified prior to entry.
Aircraft must file a flight plan (DVFR) prior to entry.
You must have a transponder with altitude encoding.
A two-way radio to give periodic reports of position to ATC is required.

30. Air Defense Identification Zone
VFR sectional chart showing an Air Defense Identification Zone (ADIZ).

31. Class G Airspace All uncontrolled airspace
Usually exists only at low altitudes
No radio, transponder or communications required
Chart has no direct indication of existence
Uncontrolled airspace is where no IFR traffic exists with a clearance
Aircraft may fly IFR in those areas but PIC assumes all risks without the assistance of ATC
Class G Airspace:
All uncontrolled airspace.
Usually exists only at low altitudes.
No radio, transponder or communications required.

32. Airspace at a Glance 60,000 ft msl 18,000 ft msl clearance trans/alt
Class A
No VFR
Class E
no radio requirement/no communication requirements
no transponder requirements except above 10,000 ft msl
E 14,500 ft msl
Class G uncontrolled/ no requirements for radio or transponder except above 10,000 ft msl
E 1,200 ft agl
C 4,000 ft
E 700 ft agl
Class B
Class C
D 2,500 ft
E Surface
E Surface
Class D
Class B
clearance
trans/alt
Class C
2 way contact
trans/alt
Class D
2 way contact

33. Other Airspace
Off Route Obstruction Clearance Altitude (OROCA): provides obstruction clearance with 1,000 ft buffer/2,000 ft in mtn ter.
Minimum Vectoring Altitudes (MVA): Established for use by ATC; 1,000/2,000 ft clearance
Min Safe/Sector Altitudes (MSA): 1,000 ft obstacle clearance w/in specified distance from the listed Navaid.
Other Airspace:
Military Training Routes (MTR).
Air Defense Identification Zones (ADIZ).
Temporary Flight Restrictions (TFR).

34. Other Airspace VFR-On-Top:
Clearance is an IFR auth to fly cleared route at the VFR altitude
Must maintain VFR visibility and cloud clearance
May be done above, below or between clouds
Pilot expected to comply with IFR rules
ATC will provide advisories only
Not authorized in Class A airpsace
Other Airspace:
Military Training Routes (MTR).
Air Defense Identification Zones (ADIZ).
Temporary Flight Restrictions (TFR).

35. Minimum In-Flight Visibility
Other Airspace:
Military Training Routes (MTR).
Air Defense Identification Zones (ADIZ).
Temporary Flight Restrictions (TFR).