Which type of airspace generally requires a transponder to operate within?

Class C airspace generally requires a transponder to operate within because it is characterized by controlled airspace around airports with a moderate level of traffic. The use of transponders in Class C airspace allows for better situational awareness and traffic management by air traffic control, ensuring that both controllers and pilots can maintain safe separation between aircraft. In this airspace, the transponder serves to provide identification and altitude information, which is essential for effective coordination among various aircraft operating in and around busy airport environments.

In contrast, Class F airspace is often used for special use or advisory areas, and does not have a standardized requirement for transponder usage, as its use is dictated by specific local regulations. Class G airspace is uncontrolled airspace and does not require transponders because it is typically used for low-altitude operations where the need for air traffic control intervention is minimal. Class E airspace is transitional airspace, which generally requires a transponder only when operating under certain conditions, such as at higher altitudes or when transitioning to or from controlled airspace, but not universally like in Class C airspace.