How are flight check aircraft callsigns read?

The correct answer is based on the standard procedure for how flight check aircraft callsigns are formatted. When using a flight check callsign, the phrase "Flight Check" is followed by the digits of the aircraft's registration number. This ensures clarity and helps in proper identification of the aircraft in communication with air traffic control. The registration number is unique to each aircraft and provides a way for controllers to accurately track and manage the flight.

Using the registration number rather than additional identifiers, such as the aircraft's manufacturer, model, or flight plan number, improves communication efficiency and reduces the likelihood of misunderstanding during operations. This is crucial in air traffic control, where clear and concise language is necessary to maintain safety in busy airspace. Other options that suggest including details like the manufacturer or model do not align with the established practices for flight check callsigns.