Class A airspace overlies the 48 contiguous United States and Alaska, including airspace overlying waters within 12 NM of the coast.
The vertical boundaries of Class A airspace are 18,000 feet MSL to 60,000 feet MSL (FL 600). Above FL600, the airspace reverts to Class E. Airspace in Alaska below 1500 AGL is not considered part of Class A airspace regardless of altitude.
All operations in Class A airspace must be conducted under IFR. VFR and SVFR flight in Class A airspace is prohibited.