Which is true about flight operations to or from Class C airspace?

When conducting flight operations to or from Class C airspace, aircraft are required to be equipped with an ATC transponder. Class C airspace is typically found around busy airports and is designed to manage air traffic safely, especially during busy arrival and departure periods. The use of an ATC transponder allows air traffic control to identify and track aircraft more effectively, thereby enhancing safety and facilitating communication within the controlled airspace environment.

Aircraft that operate in Class C airspace must adhere to specific communication and equipment requirements set forth by the Federal Aviation Administration (FAA). An ATC transponder provides critical information regarding the aircraft's location, altitude, and identity, which is essential for maintaining situational awareness among air traffic controllers and other aircraft operating in the vicinity.

The other options do not accurately represent the mandatory requirements for operating in Class C airspace. For instance, having a commercial pilot on board is not a requirement for all aircraft, as private pilots are also permitted to operate in Class C airspace as long as they comply with the necessary communication and equipment regulations. Similarly, notifying nearby aircraft and filing a flight plan are not strictly required for operations in Class C airspace, although pilot situational awareness and safety practices always encourage good communication and planning when flying in