At what minimum altitude is a turbine-engine-powered aircraft required to enter Class D airspace?

The minimum altitude at which a turbine-engine-powered aircraft is required to enter Class D airspace is 1,500 feet AGL (Above Ground Level). This regulation is in place to ensure safe vertical separation between different types of air traffic, considering the operational performance of turbine-engine aircraft.

Class D airspace typically surrounds airports where there is a control tower, and it requires pilots to be aware of and adhere to specific communications and operational rules. The higher altitude requirement reflects the need for turbine-engine aircraft, which generally have faster speeds and are capable of climbing and descending more rapidly, to maintain safe operations as they enter areas with more general aviation traffic, which may be operating at lower altitudes.

Being at 1,500 feet AGL before entering Class D airspace allows for a buffer, reducing the risk of conflict with slower aircraft that may be operating in the lower levels of the airspace. This regulation enhances safety and efficiency in managing the air traffic around controlled airports.