DAILY/PREFLIGHT INSPECTION

The daily/preflight inspection is a visual type inspection performed by the aircrew member to whom the regulator is issued, either daily or before each flight. To perform this inspection, visually inspect the following:

WARNING

WHEN WORKING WITH OXYGEN, MAKE CERTAIN THAT CLOTHING, TUBING FITTINGS, AND EQUIPMENT ARE FREE OF OIL, GREASE, FUEL, HYDRAULIC FLUID, OR ANY COMBUSTIBLE MATERIALS. FIRE OR EXPLOSION MAY RESULT WHEN EVEN SLIGHT TRACES OF COMBUSTIBLE MATERIAL COME IN CONTACT WITH OXYGEN UNDER PRESSURE.

1. Inlet and outlet connections for security of attachment. Make sure that all clamps, locknuts, fittings and screws are tight.

2. The regulator body for dents, scratches, corrosion, cracks, condition of the nameplate, or any other damage. the

3. Perform a functional test as outlined in the next inspection (special inspections). If discrepancies are found or suspected, the regulator should be taken to the Aviator's Equipment Branch for the required corrective maintenance.

SPECIAL INSPECTIONS

Special inspections are required at specified intervals in addition to the daily/preflight or calendar inspections. The interval for miniature oxygen regulators is 30 days. This inspection consists of a visual inspection and a functional test, both performed by personnel of the Aviator's Equipment Branch. To perform the special inspection, proceed as follows:

1. Visually inspect the regulator as outlined in the previous section (daily/preflight).

2. Functionally test the regulator by attaching the mask, regulator, and delivery tube to a suitable oxygen supply source. Use a regulator-to-seat hose for an attachment.

3. Turn on the supply source. There should be a flow of oxygen through the mask.

4. Don the mask and breathe. There should be a slight resistance on exhalation. This resistance is due to the positive pressure feature of the regulator.

When you finish the special inspection, record the date and place of inspection in the' 'NOTES" section of the Aircrew Personal Protective Equipment History Card.

CALENDAR INSPECTION

The calendar inspection is performed on all miniature regulators upon issue prior to being installed in an in-service personal oxygen configuration and must be performed on all miniature regulators in service at least every 90 days.

The calendar inspection consists of a visual inspection and a bench test. All work must be done in a clean, dust-free and oil-free area.

VISUAL INSPECTION

To visually inspect the miniature regulator, proceed as follows:

1. Disconnect the communication connectors.

2. Loosen the hose clamp that holds the regulator outlet to the mask delivery hose, and remove the regulator from the hose. Retain the hose clamp.

3. Loosen the locknut and remove the regulator-to-seat kit hose from the regulator inlet.

4. Inspect the regulator inlet and outlet for foreign objects, dirt, corrosion, dents, cracks, or other damage.

5. Inspect the regulator body for dents, cracks, corrosion, the condition of the nameplate, security of screws and fittings, and for other obvious damage.

Miniature regulators that fail the visual

BENCH TEST

The bench test and all other tests must be performed using an Oxygen System Components Test Stand, Model 1172AS100. Refer to chapter 11 of this training manual for identification of test stand controls and indicators referred to in the bench test procedures that follow. Do not attempt to perform any bench test before becoming thoroughly familiar with the test stand. Use a performance test inspection or the bench test must be disposed of sheet when performing the "bench test. See in accordance with any local directives. figure 12-2.

Figure 12-2.-Regulator Performance Test Sheet. 12-3

WARNING

BECAUSE OF POSSIBLE VACUUM PUMP EXPLOSION, ONLY WATER-PUMPED NITROGEN, TYPE 1, CLASS 1, GRADE B, (FED. SPEC BB-N-411) WILL BE USED IN TESTING OXYGEN REGULATORS. USE ONLY NITRO-GEN FROM GRAY CYLINDERS MARKED NITROGEN OIL FREE IN WHITE LETTERS. TWO 3-INCH WIDE BLACK BANDS MARK THE TOPS OF THESE CYLINDERS. OXYGEN TEST STANDS CONTAIN A MERCURY MANOMETER. MERCURY IS A TOPIC METAL. AVOID BREATH-ING MERCURY VAPORS. AVOID CONTACT WITH SKIN OR CLOTH-ING.