The National Airspace System (NAS) is the network of United States airspace, air navigation facilities, services, airports, regulations, procedures, technical information, human resources, and material shared jointly between the Federal Aviation Administration (FAA) and the military
Divided into categories and further classified by its complexity, density, nature of operations, level of safety required, and national and public interest
Airspace is charted and include hours of operation, altitudes, and the controlling agency (except CFAs)
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 Instrument Flight Rules (IFR) flights and to Visual Flight Rules (VFR) flights in accordance with the airspace classification
Uncontrolled airspace or Class G airspace is the portion of the airspace that has not been designated as Class A, B, C, D, or E. It is therefore designated uncontrolled airspace
Special Use Airspace (SUA) consists of airspace of defined dimensions identified by an area on the surface of the earth wherein activities must be confined because of their nature, or wherein limitations are imposed upon aircraft operations that are not a part of those activities, or both
Prohibited and restricted areas are regulatory special use airspace and are established in 14 CFR Part 73 through the rulemaking process
Warning areas, MOAs, alert areas, CFAs, and national security areas (NSA) are non-regulatory special use airspace
Special use airspace descriptions (except CFAs) are contained in FAA Order JO 7400.8, Special Use Airspace
Permanent SUA (except CFAs) is charted on Sectional Aeronautical, VFR Terminal Area, and applicable En Route charts, and include the hours of operation, altitudes, and the controlling agency
For temporary restricted areas and temporary MOAs, pilots should review the Domestic Notices found on the Federal NOTAM System (FNS) NOTAM Search website under External Links or the Air Traffic Plans and Publications website, the FAA SUA website, and/or contact the appropriate overlying ATC facility to determine the effect of non-depicted SUA areas along their routes of flight
The period of time during which a designation of special use airspace is in effect is stated in the designation
The horizontal limits of special use airspace are measured by boundaries described by geographic coordinates or other appropriate references that clearly define their perimeter
The vertical limits of special use airspace are measured by designated altitude floors and ceilings expressed as above mean sea level
Note that unless otherwise specified, the word "to" (an altitude or flight level) means "to and including" (that altitude or flight level)
When operating within SUA, Air Traffic Control (ATC) assigned airspace (ATCAA), or altitude reservations (ALTRV), flights shall be conducted under the prescribed operational area procedures appropriate to the airspace area and operation
SUA is technically separate and should not be confused with other airspace
Certain special use airspace areas can create limitations on the mixed use of airspace
When in conjunction with military operations you may hear the term MARSA, or Military Assumes Responsibility for Separation of Aircraft
Special use airspace descriptions (except CFAs) are contained in FAA Order JO 7400.8, Special Use Airspace
On National Aeronautical Navigation Products (AeroNav Products) en route charts, this information is available on one of the end panels
Airspace is charted and include hours of operation, altitudes, and the controlling agency (except CFAs)
Airspace hours of operation can be found in many places, such as sectional charts and Chart Supplement U.S.
Other Non-Charted Airspace Areas:
Stationary or Moving Altitude Reservation (ALTRV). A Stationary or Moving ALTRV is announced via an airspace NOTAM issued by the Central Altitude Reservation Facility (CARF) or ARTCC. These announcements will appear in CARF and/or ARTCC NOTAMS. This airspace ensures non-participating IFR aircraft remain separated from special activity. Non-participating VFR aircraft are permitted to fly through the area but should exercise vigilance
ATC ASSIGNED AIRSPACE. Airspace of defined vertical/lateral limits, assigned by ATC, for the purpose of providing air traffic segregation between the specified activities being conducted within the assigned airspace and other IFR air traffic. ATCAA locations and scheduled activation information can be found on the FAA SUA website; a NOTAM will not be issued to announce the activation of this airspace
Conclusion:
The national airspace system's present configuration is a reflection of the technological advances concerning the speed and altitude capability of jet aircraft, as well as the complexity of microchip and satellite-based navigation equipment
It is of the utmost importance that aircraft operating independently or under the control of a ground, ship, or airborne controller remain within the specified vertical and horizontal limits of assigned airspace. Remaining within assigned airspace can only be achieved by maintaining a total awareness of details depicted in current charts, publications, and military directives, coupled with a continual assessment of the accuracy of the controlling agency's radar. It may be required to operate with self-imposed vertical and horizontal buffers to remain within assigned airspace. When operating in designated SUA, aircrews should be aware that civilian aircraft may not honor the existence of such areas, nor monitor radio frequencies to receive appropriate warning/ advisories
It is important that pilots be familiar with the operational requirements for each of the various types or classes of airspace
When overlapping airspace designations apply to the same airspace, the operating rules associated with the more restrictive airspace designation apply
Refer to Title 14 of the U.S. Code of Federal Regulations (CFR) for specific dimensions, exceptions, geographical areas covered, exclusions, specific transponder/ADS-B or other equipment requirements, and flight operations
Regulatory airspace is established and governed through 14 CFR Part 73 through the rule making process
Not common place, there are other airspace designations such as waivered airspace that pilots may hear about, but are impractical knowledge to everyday flight operations
