Aeronautics and space. Part71:Designation of class a,b,c,d,and e airspace areas,air traffic service routes,and reporting points. SubpartA:Class a airspace. Section71.31:Class a airspace.
The airspace descriptions contained in § 71.33 and the routes contained in subpart A of FAA Order 7400.9Y (incorporated
by reference, see § 71.1) are designated as Class A airspace within which all pilots and aircraft are subject to the rating requirements, operating rules, and equipment requirements of part 91 of this chapter.