What is the speed limit for aircraft in Class D airspace below FL100?

In Class D airspace below Flight Level 100 (FL100), the speed limit for aircraft is indeed 250 knots. This regulation is in place to ensure safety and efficiency within this type of airspace, which is typically found near airports where air traffic is more concentrated and where aircraft must maintain a higher level of separation from each other as they maneuver during takeoff and landing.

Keeping the maximum speed at 250 knots in Class D airspace helps to reduce the risk of wake turbulence and ensures that the controllers can more effectively manage the flow of traffic. This speed limit allows for better handling characteristics for smaller aircraft, which are more common in this environment.

While the other speed limits for various types of airspace exist, they apply to different conditions and airspace classifications. For instance, the speed limit of 200 knots typically applies to certain portions of Class B and Class C airspace or near busy airports, while 150 knots would apply in specific restricted areas or when below 10,000 feet in more congested environments under different circumstances. However, the correct limit in Class D airspace below FL100 is 250 knots.