What is the speed limit for a USAF aircraft below 10,000 feet MSL?

The speed limit for a USAF aircraft below 10,000 feet MSL is 200 KIAS in Class D airspace. This regulation is in place to ensure the safety and efficient operation of air traffic in congested areas, particularly near airports where these class of airspaces are typically located. Class D airspace is generally around airports with operational control towers, and maintaining a lower speed helps to facilitate better communication and interaction with air traffic control, enhancing safety for both the military and civilian aircraft.

This specific limit is necessary because, at lower altitudes, the risk of mid-air collisions increases due to the density of traffic. Regulations establish these speed restrictions to manage potential conflicts as aircraft approach and depart from airports. It's essential for pilots to be aware of such limitations to comply with air traffic rules and ensure safe operations.