Who must present their pilot licence or permit upon demand?

The correct answer is that anyone holding a pilot licence or permit must present it upon demand. This requirement emphasizes the accountability and responsibility of all licensed pilots. Whether pilot-in-command or acting as a second-in-command, individuals are expected to carry their licenses and make them available to authorized personnel, such as law enforcement or aviation authorities. This regulation serves as a means of ensuring that all pilots operating an aircraft are appropriately certified and qualified, thereby upholding safety and compliance within the aviation system.

In this context, air traffic controllers and flight instructors are often mentioned in other regulations or specific circumstances but are not uniquely highlighted as the ones who must be presented with a pilot license. The stipulation applies universally to all licensed or permitted pilots, regardless of the level of their license, ensuring that safety standards are maintained across the board.