Which of the following is not a type of airspace?

The correct response highlights that Class E is indeed a type of airspace. In the United States, airspace is categorized into various classes to manage flight operations and ensure safety. Class A, B, C, and D airspaces have specific definitions and regulations associated with them, facilitating the flow of air traffic around busy airports and ensuring safe operations for both commercial and general aviation.

Class A airspace primarily consists of high-altitude airspace where all aircraft must operate under instrument flight rules (IFR). Class B airspace surrounds major airports, providing controlled airspace for large commercial airliners. Class C airspace is typically found at smaller airports and requires communication with air traffic control for entry. Class D airspace surrounds airports with operational control towers but generally involves less traffic than Class B.

Class E airspace is also an important category, defined as controlled airspace that is not classified as A, B, C, or D, which allows for greater flexibility in air traffic management. Thus, identifying Class E as not a type of airspace is incorrect, as it is an essential part of the airspace classification system.