Plain English Meaning

The gear in an aircraft that gives the people on board extra oxygen to breathe when flying high enough that normal air no longer has enough oxygen in it.

Full Definition

Aircraft equipment that stores and delivers supplemental oxygen to pilots, crew, and passengers at altitudes where the surrounding air no longer contains enough oxygen for safe physiological function. A typical system consists of an oxygen source (a high-pressure storage cylinder, a chemical oxygen generator, or an onboard oxygen-generating system), regulators that control pressure and flow, distribution lines, and masks or cannulas worn by the user. Systems are classified by how they deliver oxygen to the user: continuous-flow, diluter-demand, pressure-demand, and electronic -demand.