Commercial Pilot License (CPL) 2025 – 400 Free Practice Questions to Pass the Exam

The diluter-demand oxygen system is designed to provide oxygen on demand in response to the user's inhalation. This type of system mixes ambient air with the supplemental oxygen, allowing it to deliver oxygen only when the user inhales. This feature makes it efficient for higher altitudes, where the partial pressure of oxygen decreases.

In contrast, a continuous-flow oxygen system delivers a constant flow of oxygen regardless of whether the user is inhaling or not. This can lead to wastage, especially as the user may not always require the oxygen when it is being provided.

A pressure-demand oxygen system is typically used in emergency situations and at high altitudes, delivering oxygen under pressure to ensure that the user receives the necessary flow even when the ambient pressure is extremely low. However, it does not operate solely on the user's inhalation.

The cabin pressure oxygen system is designed to provide supplemental oxygen to all occupants within a cabin in response to cabin pressure loss, not specifically tied to individual user inhalations. Each of these systems serves different purposes, but the diluter-demand option specifically excels in providing oxygen efficiently and responsively based on the user's breathing needs.