Aircraft intended for high-altitude operations use an oxygen-supply system normally stored in which forms?

The oxygen-supply systems for high-altitude aircraft are typically stored in either gaseous or liquid states, which are suitable for the specific operational needs of such aircraft.

Gaseous oxygen is often used in pressurized systems that can be easily accessed by the crew and passengers in an emergency. It is convenient for storage in tanks that can be filled under pressure, allowing for quick delivery when needed.

Liquid oxygen, on the other hand, is utilized because it has a much higher density compared to its gaseous form. This allows for more oxygen to be stored in a compact space, which is particularly advantageous for high-altitude operations where weight and space are critical factors.

These two forms provide flexibility for the design of systems onboard, ensuring that there is adequate oxygen supply for the crew and passengers during flight at high altitudes where the atmosphere is too thin to breathe without assistance.