Oxygen Masks Used by Fighter Pilots

Why Are Oxygen Masks Needed?

• At high altitudes, oxygen content is substantially lowered, and without an external supply, pilots ran the risk of blacking out -- a loss of consciousness that, in a "dogfight" (a high-maneuverability battle between two airplanes), could be fatal. As airplanes became more powerful and their engines were able to reach higher altitudes, oxygen masks became a necessity; they were standard issue by World War Two for both the Axis and the Allied powers. Fighter pilots wore the same oxygen masks as other pilots and crewmen -- many bomber aircraft, for example, were unpressurized, so navigators, bombardiers, gunners and other crewmen all had to wear masks.

History of Oxygen Masks

• Early masks provided oxygen at a constant rate of flow, but because oxygen needs vary with altitude, this type was quickly superseded by regulators, known as "diluter-demand" to distinguish them from other types, that carefully mixed oxygen in with the air surrounding the airplane. This permitted flight operations at much higher altitudes, but fighter performance quickly outpaced this -- by the end of World War Two, the Ta-152 interceptor had been designed for use up to nearly 50,000 feet. At these altitudes, ambient pressure isn't sufficient to deliver oxygen, and newer masks -- known as "pressure-demand" masks -- supply air at a higher pressure to keep the pilot in the fight.

COMBAT EDGE

• In the early days, the chief concern of oxygen masks was simply the altitude. Today, however, fighter pilots are also limited by the "g-forces" they experience -- in a steep turn, a fighter pilot might be subjected to gravity forces many times greater than he would experience resting on the Earth's surface. When performing these maneuvers, fighter pilots run the risk of G-LOC -- "gravity-induced loss of consciousness" -- as gravity draws blood away from their heads and the increased pressure makes it more difficult to breathe. As a result, the United States military introduced COMBAT EDGE; when a modern aircraft like the F-15, F-16 or F-22 detects a high-g maneuver, additional pressurization is added to the air supply (this is known as "pressure breathing for g," or PBG) and air bladders around the pilot inflate to help even out the pressure, allowing the pilot to continue breathing even in very stressful maneuvers.

Modern Oxygen Masks

• Modern fighter pilots in the United States military generally use one of two oxygen mask types. The MBU-12/P and MBU-14/P (the latter being a variant for the Navy with slightly redesigned connectors) are pressure-demand masks suitable for use at a wide range of altitudes. The MBU-20/P and MBU-24/P (again, the latter being intended for the United States Navy) are pressure-demand systems that additionally support the COMBAT EDGE technology. All these masks have integrated microphones that work with headphones mounted inside the fighter pilot's helmet, forming a complete life support and communication system.