Final answer:
The pilot-in-command or captain of the aircraft is responsible for ensuring that flight duty time limits are not exceeded in a commercial air service operation.
Step-by-step explanation:
In a commercial air service operation, the responsibility to ensure that flight duty time limits are not exceeded falls on the pilot-in-command (PIC) or the captain of the aircraft. The PIC is the final authority on the operation of the flight and has the ultimate responsibility for the safety of the aircraft, crew, and passengers.
The PIC is required to adhere to regulations set by the Federal Aviation Administration (FAA) and the airline's policies regarding flight duty time limitations and rest requirements for pilots. These regulations are in place to prevent pilot fatigue and ensure the safety of the flight.
For example, the FAA has introduced limits on the maximum number of flight hours a pilot can accumulate within a certain time period, and also mandates minimum rest periods for pilots between flights. The PIC is responsible for managing and monitoring the flight duty time of the crew to ensure compliance with these regulations.