What characterizes Class E airspace?

Class E airspace is primarily characterized by its designation as controlled airspace that typically begins at a specified altitude, which is often 700 feet above ground level (AGL). This controlled airspace allows for various types of aviation operations under specific conditions and provides essential separation and safety protocols for air traffic.

Class E airspace can vary in its ceiling and is designed to accommodate IFR (Instrument Flight Rules) and VFR (Visual Flight Rules) aircraft operations, typically expanding upward from either the surface or a specified altitude (like 700 feet AGL) to the overlying airspace. It is essential for maintaining order and safety in areas where both IFR and VFR aircraft may be operating and ensures that sufficient airspace is available for those operations.

In contrast, uncontrolled airspace does not apply to Class E airspace since it falls under the category of controlled airspace. Additionally, while Class E can be designated as beginning at the surface in certain areas, that is not universally true since it can also extend from higher altitudes, which distinguishes it from Class G, which is entirely uncontrolled. Therefore, the statement regarding the floor at 700 feet AGL is one key characteristic of Class E airspace, making it the most accurate choice.