ACCEPTANCE/SPECIAL/DAILY INSPECTIONS

The acceptance/special/daily inspections consist of a visual inspection followed by a functional test. These inspections and tests are performed in conjunction with the aircraft inspection requirements for the aircraft in which the regulators are installed. These inspections are performed at the organizational level by AMEs. However, you should know what they are supposed to inspect. Refer to table 12-4 for assistance in troubleshooting. To perform the inspection, visually inspect the regulators as you did in the preflight inspection.

Table 12-4.-Troublesbooting (Daily, Preflight, Special, Turnaround, Transfer and Acceptance Inspections)

To perform the functional test proceed as follows:

1. Place the supply valve control lever in the ON position.

2. Place the diluter control lever in NORMAL OXYGEN position.

3. Using an oxygen mask and hose assembly, connect the hose to the quick disconnect. While at ground level, the regulator will not supply oxygen from the supply system to the mask. The emergency pressure control lever must be used in order to check out the oxygen supply function of the regulator at low altitudes. (The emergency lever is spring loaded at the NORMAL position, and will return to NORMAL when released.) Place the mask to your face with the regulator in test mask position and inhale. Proper regulator operation will be indicated by the flow indicator assembly showing white during inhalation and black during exhalation.

4. Hold the emergency pressure control lever in the TEST MASK position and observe the flow indicator. The flow indicator should be white, indicating a flow through the regulator.

Upon completion of the functional test, secure the regulator as follows:

1. Disconnect the mask from the supply hose.

2. Ensure that the emergency pressure control lever returns to its NORMAL position.

3. Place the diluter control lever in the 100-percent position.

4. Place the supply valve control lever in the OFF position.

If any discrepancies are found or suspected, notify maintenance control. If repairs cannot be made in the aircraft, replace the regulator and forward the defective regulator to AIMD for repairs.

CALENDAR/PHASED/SDLM INSPECTIONS

You must remove the regulator to give it a calendar, phased or SDLM (standard depot-level maintenance) inspection. See applicable Planned Maintenance System (PMS) publications for specified intervals. In no case can the interval exceed 231 days. Upon removing it from the aircraft, the regulators are visually inspected and sent to AIMD for bench testing.

Aircraft panel-mounted regulators that fail the bench test must be repaired. Source, Maintenance and Recoverability (SM&R) codes define repairability of components and lowest level of maintenance authorized.

Service Life

Oxygen regulators remain in service for as long as they function correctly and do not require excessive repair (exceeds 75-percent of original cost of regulator). All silicone rubber parts are replaced whenever a regulator is disassembled for repair.

Bench Test

Bench tests are performed on aircraft panelmounted oxygen regulators prior to being placed in service, and during the phase/calendar or SDLM inspection cycle of the aircraft in which installed. See applicable PMS publications for specific intervals. The inspection interval must not exceed 231 days. The regulators are also subjected to a bench test if malfunction is suspected, and after repair or replacement of damaged parts.

Bench tests are performed using Oxygen System Components Test Stand, Model 1172AS100, in accordance with NAVAIR 13-1-6.4. Because of the complexity of the 1172AS100 test stand, it is essential that the operator become thoroughly familiar with the test stand prior to performing bench tests.

NOTE: Nitrogen supply cylinders used in testing oxygen components are 80 cubic feet and contain a maximum pressure of 2000 200 psig. For tests requiring pressures of 1800 psig, use highest available pressure, but in no case can this pressure be less than 500 psig.