Both the A-10-A and the A-14 masks are suspended from the summer and winter flying helmets.

NOTE: It is important that AERIAL GUNNERS obtain a properly fitting mask, fit to both summer and winter helmets at the first station available. Because of the extreme cold to which gunners are subjected under combat conditions, you MUST learn to remove and replace the mask quickly and accurately WEARING HEAVY GLOVES. It is not easy to manipulate a mask or unjam a .50 cal. gun with numb fingers in heavy flying gloves. PRACTICE these things on every training flight with gloves ON.

FITTING THE MASK TO THE FACE -- There are two considerations in obtaining a proper fit:

  1. An AIR-TIGHT SEAL of mask to face.
  2. Comfort of fit without undue pressure.

The A-10-A and A-14 masks come in three sizes. Roughly, 60% of flyers will require the STANDARD (medium) size mask, 30% the LARGE mask, and the remaining 10% the SMALLER sizes. General instructions concerning fitting are.

  1. Suspension points on both summer and winter helmets must be determined INDIVIDUALLY on each flyer. This is a job for your squadron personal equipment officer or the group aviation physiologist or his trained assistant.
  2. It is important that the mask be suspended high on the face, sealing to the boney portion of the nose and cheek bones and NOT the soft tissues. Otherwise you'll get a leak or a "clothespin on the nose" effect from pressure of the nose wire.
    NOTE:
    1. Be sure the regulator hose clip or the clip on the walk-around bottle is clipped high enough on your clothing to remove all tension from mask hose--otherwise the mask will be pulled down on the face and will leak outside air.
    2. Above 25,000 feet with the temperature 20 degrees and lower, the tissues of the face contract and the rubber mask loses its pliability. Under these conditions, the mask tends to fall away from the face and it becomes necessary to SHORTEN THE UPPER SUSPENSION STRAPS. On returning to warmer altitudes, these must be loosened again to avoid discomfort from a too tightly fitting mask. (Applies chiefly to gunners).
  3. Excessive beard stubble will hold the mask away from the face and cause leak around the jaws.
  4. See page 35 for care of mask.
  5. TESTING FOR LEAKS -- Holding the thumb over the end of the mask tube (rapid disconnect) and inhaling GENTLY should cause the mask to collapse on the face. The most common place for a leak is alongside the bridge of the nose. The actual site of leak is determined by putting finger-point pressure beside the nose and over the cheek bones, one point at a time. The nose wire is then re-adjusted to cause pressure at this point. Be sure the mask is high enough on the face and on the bridge of the nose. If the seal is still below the boney portion of the nose try the next largest size mask.
  6. "SNIFF-TESTER" -- An effective "sniff-tester" for detecting small leaks can be obtained as follows: Obtain one of the commercial nasal inhalers - Benzedrine, Vick's, Penetro (or metal tube of comparable size). Cut off the end ordinarily inserted into the nose flush with the barrel of the container, and remove contents. Fit barrel with an airtight cork stopper. Straighten a paper clip or take a piece of wire of similar gage, cut to 2½ inch length, and drive one end firmly into lower side of cork stopper. Fashion other end of wire into a 1/4 inch fish hook bend. Make a ball of cotton or tightly wrapped gauze, ½ inch in diameter, and attach to bent end of wire. Soak the cotton or gauze, in oil of peppermint or oil of cloves (obtained from squadron dentist or flight surgeon) and fit cork stopper, carrying the "sniff-tester" tightly into metal container. To "sniff-test", remove the stopper and hold the cotton plug on both sides of the nose at the top of the mask (eyes closed). Inhale gently with the mask hose blocked. A leak is present if the contents of the "sniff-tester" is detected. Rough as this test seems, it is very sensitive.
  7. NOTE: The "sniff-tester" is also effective in testing the DEMAND REGULATOR for leaks. Put on mask. Fit snugly to face. Plug into regulator hose. Turn Auto-Mix (Air) Lever OFF. Hold sniff-tester close to regulator diaphragm and breathe normally several times. If the contents of the sniff-tester" are detected, the regulator has a leak.

TWO TYPES OF "SNIFF-TESTERS"

  1. Cotton pledget soaked with oil of peppermint.
  2. Benzedrine inhaler containing blotter soaked with oil of peppermint.

Fig. 1