Definition
An oxygen regulator attached directly to the oxygen mask itself, rather than mounted on the aircraft panel or a remote location. It controls the flow and pressure of oxygen delivered to the pilot at the point of use, and is typically used in pressure-demand systems for high-altitude flight.
Plain English
The valve that controls how oxygen is delivered to the pilot is built into the mask, so it sits right on the pilot's face instead of somewhere on the aircraft.
Context Anchor
Seen in high-altitude oxygen system discussions, especially pressure-demand oxygen systems and emergency oxygen equipment checks.
Derivation
Regulator comes from Latin regula, meaning “rule” or “straight guide.” In aviation equipment, a regulator is a device that keeps something controlled within the needed range. Here, it controls the oxygen going into the mask.
Why Pilots Care
Ensures reliable oxygen delivery above 30,000 feet where cabin pressure alone is insufficient, directly preventing hypoxia.
Intuition Check
Do not read “mask-mounted regulator” as just a mask attachment. The important part is that the oxygen control device is built onto the mask itself and regulates the oxygen the wearer breathes.
Example Sentence 1
The aircraft was equipped with a mask-mounted regulator, allowing the pilot to control oxygen flow directly from the mask rather than reaching for a panel control.
Example Sentence 2
Preflight checks included verifying that the mask-mounted regulator delivered positive pressure on demand.