Define “uncontrolled airspace”.

Uncontrolled airspace refers to any airspace that is not designated as controlled airspace by air traffic control authorities. In uncontrolled airspace, pilots can navigate without the need for air traffic control clearance, and they must follow visual flight rules (VFR) for navigation, which allows for a greater degree of operational freedom. This type of airspace is typically found at lower altitudes and encompasses a significant portion of the airspace, making it available for both manned and unmanned aircraft operations.

The other choices do not accurately represent the characteristics of uncontrolled airspace. For instance, designating airspace for recreational use only is misleading because uncontrolled airspace can be utilized for a variety of purposes beyond recreation. The notion that uncontrolled airspace is solely for UAS operations ignores the fact that it is available to all types of flight operations. Additionally, while some airspace may be reserved for military use, that does not define uncontrolled airspace, as it can be used by civilian pilots as well.