Which airspace classes are UAV operations mostly restricted to?

UAV operations are primarily restricted to Class D, E, and G airspace due to regulations that ensure both safety and the efficient management of air traffic. These classes of airspace are generally less congested and often have lower levels of air traffic control oversight compared to Classes A, B, and C.

Class D airspace typically surrounds smaller airports and has a controlled environment, but still allows for the presence of UAVs with proper authorization. Class E airspace is often designated as controlled airspace that does not require a control tower, providing a level of flexibility for UAV operations while maintaining certain regulations and visibility requirements. Finally, Class G airspace is uncontrolled, making it the most permissive for UAV operations, where pilots can operate with minimal restrictions.

The other options involve classes of airspace that either require more stringent regulations or are not typically classified in relation to UAV operations. For example, Class A airspace is primarily for high-altitude jet operations and requires pilots to operate under instrument flight rules, which is not suitable for most UAVs that operate at lower altitudes. This understanding is crucial for maintaining safety and compliance within the National Airspace System (NAS).