Commercial Pilot License (CPL) Practice Exam

Pressure demand oxygen systems are specifically designed to deliver oxygen to pilots and passengers operating at higher altitudes, typically above 30,000 feet. At these elevations, the atmospheric pressure decreases significantly, leading to a decrease in the amount of available oxygen, which can result in hypoxia—a condition where the body is deprived of adequate oxygen.

Pressure demand systems work by providing oxygen at a pressure that is equivalent to the pressure surrounding the user, ensuring that adequate amounts of oxygen are delivered even as the aircraft ascends above this critical threshold. This is crucial for maintaining cognitive and physical functions in the crew and passengers when flying in such environments.

While supplemental oxygen may be required at lower altitudes, the necessity for pressure demand systems primarily initiates once an aircraft operates above 30,000 feet, where it's essential to ensure safety and performance during the flight. The choice of operating altitude also takes into account the operational safety standards and regulations that govern flight operations at high altitudes.