# Key Takeaways - The US uses class A, B, C, D, E, G airspace, listed from most to least restrictive. - All except Class G are controlled airspace. - Class D airspace may revert to Class E or G when the tower is closed. # Details ## Overview All airspace in the US is classified depending on its uses. These classes carry with them certain restrictions, including things like equipment required and minimum weather allowed for VFR flight. ![[Airspace Cross Section.jpeg]] Each airspace has a different purpose and definition of it's size and shape. See the [[AIM 3]] for more details on this. ## Distinctions Between Classes > [!quote] From [[PHAK Ch15]] > The categories and types of airspace are dictated by the complexity or density of aircraft movements, nature of the operations conducted within the airspace, the level of safety required, and national and public interest. ### Controlled Airspace > [!quote] From [[PHAK Ch15]] > Controlled airspace is a generic term that covers the different classifications of airspace and defined dimensions within which air traffic control (ATC) service is provided in accordance with the airspace classification. This includes Class A, B, C, D, E. ### Uncontrolled Airspace This is simply airspace not designated as class A, B, C, D, or E. [[ATC]] has no authority or responsibility to control air traffic there, but VFR weather minimums still apply. > [!tip] > Some Class D airports may revert to either a Class E or Class G when the tower is closed. ### Special Use Airspace - Prohibited areas: Flight prohibited (e.g. White House) - Restricted areas: Not wholly prohibited, but has restrictions. Contact the controlling agency for permission. May be extremely hazardous to enter without permission. - Warning areas: Similar to restricted, but not solely US jurisdiction (e.g. over ocean) - Military operation areas ([[MOA]]s): Separate certain military operations from IFR traffic. VFR pilots should exercise caution if traversing a MOA - > [!quote] From [[AIM 3]] > The activity status (active/inactive) of MOAs may change frequently. Therefore, pilots should contact any [[FSS]] within 100 miles of the area to obtain accurate realtime information concerning the MOA hours of operation. - Prior to entering an active MOA, pilots should contact the controlling agency for traffic advisories - Alert areas: Use caution for high volume of pilot training or unusual aerial activities - Controlled firing areas ([[CFA]]s): Not charted, as activities suspended when aircraft spotted - National Security Areas ([[NSA]]s): Pilots requested to avoid flight through for increased security and safety of ground facilities ### Published VFR Routes - VFR Flyways - VFR Corridors (eg over KLAX) - Class B Airspace VFR Transition Routes ### Other Airspace Other airspaces also exist. Make sure to check for these before you fly! - Mode C Veil - [[TFR]]s - Terminal Radar Service Area ([[TRSA]]) - Special Air Traffic Rules ([[SATR]]) and Special Flight Rules Area ([[SFRA]]) - [[MTR]]s ## Requirements for Airspace Operations ### Equipment ![[Requirements for Airspace Ops.jpeg]] ### VFR Weather See [[FAR 91.155 VFR Weather Minimums]]. ## Relevant FARs/AIM > [!example]- Controlled Airspace > - [[AIM 3]]-2 > - [[FAR 91.129 Class D Ops]] > - [[FAR 91.130 Class C Ops]] > - [[FAR 91.131 Class B Ops]] > - [[FAR 91.135 Class A Ops]] > [!example]- Class G Airspace > - [[AIM 3]]-3 > - [[FAR 91.126 Class G Airspace Ops Near Airport]] > [!example]- Special Use > - [[AIM 3]]-4 > - [[FAR 91.133 Restricted and Prohibited Areas]] > - [[FAR 91.137 TFRs in Disaster or Hazard Areas]] > - [[FAR 91.141 Presidential TfFRs]] > - [[FAR 91.143 Space Flight TFRs]] > - [[FAR 91.145 Aerial Demos and Sporting Event TFRs]] # Additional Resources - [FAA Airspace for VFR Flight](https://youtu.be/wYKI-4XKp1c) - [[AIM 3]] - [[PHAK Ch15]] - [[Sectional Chart]] ## FAA Definition ***Definition*** :: The common network of United States airspace—air navigation facilities, equipment and services, airports or landing areas; aeronautical charts, information and services; rules, regulations and procedures, technical information; and manpower and material. ***Source*** :: [[PHAK Glossary]] #glossary #concept