Plain English Meaning

A required quality level for the oxygen pilots breathe in flight. It must be very pure and very dry, so it works reliably at altitude and won't freeze or contaminate the system.

Full Definition

A specification for the oxygen used in aircraft breathing systems requiring at least 99.5% pure oxygen by volume, with no more than 0.005 milligrams of water per liter and minimal other contaminants. This grade is designated as 'Aviator's Breathing Oxygen' (ABO) and is the only oxygen approved for use in aircraft oxygen systems.

Context Anchor

Seen when studying aircraft oxygen systems, servicing oxygen bottles, or choosing the correct type of oxygen for flight.

Derivation

“Aviator” comes from a Latin word for bird and came to mean a person who flies. “Oxygen” comes from Greek roots originally meaning “acid-former,” an early mistaken idea about the . In this term, the important is that “breathing oxygen” means oxygen prepared for people to breathe, and “aviator’s” narrows it to the stricter use.