Definition
A supplemental oxygen system that delivers oxygen at a steady, constant rate from a storage cylinder, through a regulator, to the user's mask whenever the system is turned on, regardless of whether the user is inhaling or exhaling. A rebreather-type mask captures some of the exhaled oxygen in a bag for the next breath, reducing waste. Typically approved for use up to 25,000 feet.
Plain English
An oxygen system that flows oxygen out at a steady rate the whole time it's on, instead of only when you breathe in. A bag on the mask catches some of what you breathe out so you can use it on your next breath.
Context Anchor
Seen in high-altitude flight planning, aircraft oxygen equipment descriptions, and passenger oxygen systems.
Derivation
"Continuous flow" simply describes how the oxygen moves: nonstop, rather than in pulses. The name distinguishes this system from a diluter-demand or pressure-demand system, which only releases oxygen when the user inhales.
Why Pilots Care
It provides reliable oxygen delivery during high-altitude flight to prevent hypoxia, though it wastes some oxygen compared to demand systems.
Analogy
It is like a faucet left slightly open: the flow continues until you turn it off, whether or not someone is using the water at that moment.
Intuition Check
Continuous does not mean the pilot is breathing pure oxygen every second. It means the system keeps sending oxygen while it is turned on, including between breaths.
Example Sentence 1
Before climbing above 12,500 feet, the pilot turned on the continuous flow oxygen system and confirmed the flow indicator showed green.
Example Sentence 2
Unlike demand systems, a continuous flow oxygen system supplies oxygen even during exhalation.