FLOW INDICATOR

Either the bouncing ball or blinking eye will be at each station, depending on the vintage of your ship. Only older ships will be equipped with the bouncing ball which is no longer manufactured. These indicators do not tell HOW MUCH oxygen you are getting ... they merely indicate that some oxygen is flowing through the system when you take a breath. They may be working O.K. even though your oxygen supply is inadequate. The COLOR OF YOUR FINGER NAILS is a better guide to the amount of oxygen you are getting, providing your hands are warm. If they become bluish above 20,000 feet check mask and connections for leak. Naturally, you won't remove your gloves to look at your finger nails if the temperature is 20 or 30 degrees below zero. If no leak is found, switch the "Auto-Mix" to the OFF position and note if things improve. INFORM YOUR PILOT IF AUTO MIX IF LEFT "OFF" and your mission is a long one.

Fig. 9

IN THE AIR:

  1. Check for leak by blockage and gently inhalation each time mask is removed and replaced.
  2. Check oxygen flow indicator at regular intervals. Also, CHECK COLOR OF NAILS AT REGULAR INTERVALS -- if blue above 20,000 feet turn Auto-Mix to "OFF" position.
  3. Check oxygen pressure gauge frequently.
  4. If temperature is below freezing, manipulate mask to free it of ice at regular intervals. Wiping moisture from mask periodically will prevent freezing of mask.
  5. Open EMERGENCY flow only when absolutely necessary ... notify pilot.
  6. Over 28,000 feet switch Auto-Mix to "Off" position ... turn back to "ON" position below this altitude.
  7. Re-fill walk-around bottle frequently when you are using it at altitude.
  8. Avoid unnecessary exercise above 20,000 feet ... take your time!
  9. Observe your fellow crew member at frequent intervals above 20,000 feet. You can recognize before he can if he's in trouble.

ON RETURN TO FIELD

  1. Wipe mask dry. It should be thoroughly cleansed with soap and water (inside) after 10 to 14 hours use. Be sure that exhaust flutter valve is kept clean.
  2. Inspect mask for leaks or cracks in face-piece.
  3. Change strap adjustment only to take up natural stretch slack.
  4. Lend your mask only in extreme emergency.
  5. Protect your mask from hot sun, moisture, and rough treatment.
  6. Report all defective oxygen equipment to ground crew and to personal equipment officer immediately on landing. See that it has been repaired or replaced before another altitude mission.