37e0e73a_pace_Classification___ASPMHelp__Description
[Class] Class A [Description] 
Generally, airspace from 18,000 feet mean sea level (MSL) up to and including fl ight level (FL) 600, including the airspace overlying the waters within 12 nautical miles (NM) of the coast of the 48 contiguous states and Alaska. Unless otherwise authorized, all pilots must operate their aircraft under instrument flight rules (IFR).
Airspace Classification - ASPMHelp
Description