What generally defines Class E airspace?

Class E airspace is predominantly characterized as controlled airspace that extends from a designated floor up to, but not including, 18,000 feet above mean sea level. This type of airspace is crucial for the regulation of both visual flight rules (VFR) and instrument flight rules (IFR) operations.

One of its primary roles is to ensure that aircraft operating under IFR are provided with air traffic control services to maintain safe separation from other aircraft, especially in areas where altitude and congestion could pose a risk. Class E airspace can exist in various forms, such as extending from the surface, from a specified altitude, or even in the form of a transition area extending up to 18,000 feet.

This airspace serves as a buffer between uncontrolled airspace and higher altitude controlled airspace, allowing for a seamless transition between different airspace classes for various types of flight operations. Understanding this concept is key for pilots to navigate and operate safely within the National Airspace System.