If the airspace is not Class A, B, C, or D, what classification does it fall under?

In the National Airspace System, airspace that is not classified as Class A, B, C, or D falls under Class E airspace. Class E airspace is a type of controlled airspace that extends upwards from either the surface or a designated altitude, and it may be used by aircraft operating under both visual flight rules (VFR) and instrument flight rules (IFR).

The key characteristic of Class E airspace is that it serves as a transition zone between the terminal airspace associated with airports and the more uncontrolled airspace beyond it. It includes airspace designated for instrument procedures and can be found in various forms, such as in the vicinity of airports or at higher altitudes, allowing for effective control and management of air traffic.

While Class G airspace is another option wherein the airspace is not controlled, it is specifically defined as uncontrolled airspace. This means that it does not provide the same level of air traffic control services as Class E. Restricted airspace, on the other hand, serves specific purposes (like military operations) and still signifies controlled airspace but is not a standard classification for all remaining airspace.

Thus, the correct answer is Class E airspace, as it represents a significant classification of controlled