What is the primary purpose of aircraft pressurization?

The primary purpose of aircraft pressurization is to reduce or prevent decompression sickness and hypoxia. In high-altitude flights, the atmospheric pressure decreases significantly, which can lead to the physiological effects of low oxygen levels in the body, known as hypoxia. Additionally, without cabin pressurization, the risk of decompression sickness increases as the body can no longer effectively handle the changes in pressure, especially during rapid ascents or descents.

By maintaining a controlled and higher pressure within the aircraft cabin, pilots and passengers are provided with a safe environment where they can breathe comfortably and function normally, despite being at altitudes where oxygen levels are insufficient for human survival. This crucial function supports overall safety and well-being during flight, allowing aircraft to operate efficiently in high-altitude environments.

The other potential purposes listed, such as increasing cabin noise levels, enhancing external visibility, or minimizing flying time, do not align with the critical need for safeguarding passengers and crew against altitude-related health risks.