A coded transponder with altitude reporting equipment is required for which airspace?

The requirement for a coded transponder with altitude reporting equipment applies to Class A, Class B, and Class C airspace due to the need for effective air traffic control and situational awareness in these crowded airspace categories. Class A airspace, which extends from 18,000 feet up to and including FL600, is where only IFR flights are permitted, and having a transponder is essential for ensuring separation between aircraft.

Class B airspace, which typically surrounds major airports, requires transponders to provide air traffic controllers with accurate information about aircraft positions, enhancing safety and efficiency in high-traffic areas. Similarly, Class C airspace, which encompasses airports that have a certain level of air traffic control services, mandates the use of transponders to improve communication and monitoring of aircraft.

In contrast, other options such as only Class C or only recreational airspace do not reflect the comprehensive requirement that encompasses multiple classes of airspace. The classifications work together to maintain safety standards in various flying conditions and environments, thereby reinforcing the need for transponders in these critical airspace categories.