What does the active pressure controller do in a pressurized cabin?

The active pressure controller plays a crucial role in maintaining the safety and comfort of passengers and crew in a pressurized cabin. Its primary function is to monitor and adjust the internal cabin pressure to ensure that the cabin altitude remains at safe levels, particularly during ascent and descent.

As an aircraft climbs, the outside air pressure decreases, and without proper pressure control, the cabin could experience a drop in pressure that would be unsafe for occupants. The active pressure controller automatically adjusts the outflow valves and other mechanisms to maintain the cabin at a predetermined altitude, which is much lower than the actual flight altitude. This helps to prevent altitude-related physiological effects like hypoxia, ensuring that everyone on board can breathe comfortably and remain safe throughout the flight.

The other choices do not accurately reflect the function of the active pressure controller; while fuel efficiency, air conditioning, and cabin lighting are important aspects of aircraft operation, they fall under different systems and do not pertain to the specific role of maintaining cabin pressure.