Final answer:
The air marshal's signals provide a standardized method of communication with the pilot on board an aircraft, especially in emergency situations. They convey important information quickly and efficiently, ensuring the safety and security of the aircraft.
Step-by-step explanation:
The air marshal's signals are useful for communicating with a pilot on board an aircraft because they provide a standardized and universally understood method of communication. Just like pilots and air traffic controllers communicate in English regardless of their native language, air marshals use specific signals to convey important information to the pilot, especially in emergency situations where verbal communication may be difficult or not possible.
For example, the air marshal might use hand signals to indicate that there is an imminent threat or to instruct the pilot to take specific actions such as landing the aircraft immediately or changing its course.
These signals are crucial for ensuring quick and efficient communication between the air marshal and the pilot, which can help in maintaining the safety and security of the aircraft and its passengers.