An operable 4096 code transponder with an encoding altimeter is required in which airspace?

In the context of transponder requirements, the correct answer indicates that an operable 4096 code transponder with an encoding altimeter is necessary for Class B airspace and within 30 miles of the Class B primary airport. This requirement is in place to enhance safety and situational awareness in busy airspace where high-density traffic is common. The use of a transponder helps air traffic control (ATC) identify and track aircraft more effectively, allowing for better traffic management.

Class B airspace is typically found surrounding major airports, where the volume of air traffic necessitates stringent regulations to ensure safety. The inclusion of the 30-mile radius from the primary airport is also significant, as it reinforces the need for aircraft operating in this vicinity to be equipped with the necessary transponder, even when flying in and out of the outer areas of this airspace. This reflects an approach to promote safety not only in the most congested areas but also in the surrounding zones that may still experience significant traffic.

Understanding these transponder requirements is essential for pilots operating in or near airports with heavy traffic, as compliance helps prevent mid-air collisions and enhances overall safety in aviation.