MASK TO REGULATOR CONNECTION
(RAPID DISCONNECT)
IS THE RUBBER GASKET IN PLACE? Without the gasket an air-tight seal at this joint is impossible. Dangerous oxygen-lack will result above 24,000 feet. With a leak at this altitude serious mental and physical inefficiency will develop, even though you may not pass out. Above 28,000 feet you will quickly become punch drunk, and the pass-out will soon follow.
USE THE CLIP ON THE REGULATOR TUBING--It is there to remove tension on this connection which could (1) cause serious mask leak by pulling the mask down on the face, or (2) cause mask tubing to become disconnected. In combat these things would fail to attract your attention. Without warning you are first slap-happy and then drop unconscious.
THE RAPID DISCONNECT REQUIRES CONSTANT ATTENTION whether you are plugged into a fixed station or into a walk-around bottle. A pull of at least 12 pounds should be required to separate the male and female connection of the rapid disconnect. The security of the connection can be increased by spreading the groups at the tip of the male connection. (See diagram, pre-flight check, page 39).
CONNECTION OP HOSE TO REGULATOR IS NOT A SWIVEL JOIN--Above 24,000 feet the collar must be turned up tightly to prevent a dangerous leak of air.
Make sure that the regulator hose is wired securely to the goose neck on the regulator.
THE DEMAND (A-12) REGULATOR
In principle the demand regulator is a diaphragm-operated flow valve which is opened by the user's inspiration and closes automatically when the suction ceases. This gives you as much oxygen as you ask for. All you do is breathe. A short breath draws a short squirt of oxygen, while deep, rapid breathing brings forth large shots in rapid succession.
The regulator can be set to conserve oxygen, or to give you 100% oxygen, regardless of the altitude you are flying. This is governed by the position of the "Auto-Mix" (AIR) lever.
AUTO-MIX (AIR) "ON" (or NORMAL OXYGEN) is the position for routine use. This saves oxygen.