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Class A Airspace

Class A “Alpha” Airspace

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…”

SR71 ground school