Is a Mode C transponder required for flight over Class C airspace below 10,000 ft MSL?

A Mode C transponder is indeed required for flight in Class C airspace below 10,000 feet MSL. Class C airspace has specific requirements to ensure safe and effective air traffic management due to the higher density of aircraft operations in these areas. The regulation mandates that aircraft operating in and around Class C airspace must have a functioning Mode C transponder, which provides altitude information to air traffic control. This altitude reporting capability allows for more efficient separation and traffic management, enhancing safety for all aircraft operating in the vicinity.

Class C airspace generally extends from the surface to 4,000 feet above the airfield elevation, and the requirement for a Mode C transponder remains in effect up to 10,000 feet MSL to account for the various altitudes at which aircraft may operate within or near this type of airspace.