MAINTENANCE Maintenance of the type CRU-79/P regulator is limited to inspection, testing, adjustment of the pressure breathing aneroid, and tightening of loose screws. Ensure that antiseize tape is used on pipe threads. This section contains only the procedural steps necessary to meet these requirements. NOTE: Upon completion of any maintenance action (for example, inspec- tion, adjustment, modifications, etc.), be sure to complete the required maintenance data collection system forms. If the regulator fails any inspection or testing requirements, it must be disposed of in accordance with any local directives and replaced with a ready for issue (RFI) component. The miniature regulator will remain in service as long as it continues to function correctly and does not require other than authorized adjustment. Procedural steps outlined in this section are listed under the inspection cycle in which they are required, and in the sequence in which they normally occur. 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 EQUIP- MENT ARE FREE OF OIL, GREASE, FUEL, HYDRAULIC FLUID, OR ANY COMBUSTIBLE MATERIALS. FIRE OR EXPLOSION MAY RESULT WHEN EVEN SLIGHT TRACES OF COM- BUSTIBLE 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. 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 Equip- ment 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 Equip- ment 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. 12-2