Class E Airspace
If the airspace is not Class A, B, C, or D, and it is controlled airspace, then it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude to the overlying or adjacent. When designated as a surface area, the airspace is configured to contain all instrument procedures. Federal airways are also in this class, beginning at either 700 or 1,200 feet above ground level (AGL) used to transition to and from the terminal or en route environment, and en route domestic ad offshore airspace areas designated below 18,000 feet MSL. Unless designated at a lower altitude, Class E airspace at 14,500 MSL over the United States, including the airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, and Alaska, up to but not including 18,000 feet MSL, and the airspace above FL 600. Each pilot operating an aircraft or in the vicinity of an airport in a Class E must comply with the requirements of Class G airspace and traffic patterns, unless otherwise required by 14 CFR part 93. If the aircraft radio fails in flight under IFR, the pilot should continue the flight by the route assigned in the last ATC clearance received, or if being radio vectored, by the direct route of radio failure to the fix, route, or airway specified in the vector clearance. In the absence of an assigned route, the pilot should continue by the route that ATC advised may be expected in a further clearance, or if a route had not been advised by the route filed in the flight plan.