Which oxygen system generally requires the least maintenance in pressurized aircraft?

Chemical oxygen generator systems are acclaimed for their minimal maintenance requirements in pressurized aircraft. These systems produce oxygen through a chemical reaction, which means they do not require the regular refills or pressurization checks that other systems might need. Once installed, they can operate effectively for long periods without intervention.

In contrast, systems that rely on liquid oxygen or compressed gas require more frequent maintenance due to the need for monitoring fuel levels and potential pressure checks. Liquid oxygen systems must also be managed carefully to avoid leaks, as well as dealing with the properties of the cryogenic liquid. Combination systems, which utilize both features, often inherit the maintenance complexities and requirements of their individual components.

Therefore, the choice of chemical oxygen generator systems stands out as the most efficient and least maintenance-intensive option for ensuring a reliable supply of oxygen in pressurized environments, making them the preferred choice in many modern aircraft designs.