MIL-L-27160 (USAF)
(Copies of documents required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.)
3. REQUIREMENTS
3.1 Qualification or preproduction. Qualification or preproduction provisions shall be as specified in the applicable instrument specification.
3.2 Materials. The instrument lighting system shall be of materials that will enable it to withstand the service, functional, and environmental conditions specified by the applicable instrument specification.
3.3 Design and construction. The lighting system shall be contained within the instrument case. A minimum of two lamps shall be used for each instrument. The lighting system shall not interfere with the visibility of any portion of the dial or scale. No one portion of the display shall depend upon one lamp for its illumination. The lighting system shall in no way interfere with correct operation of the instrument.
3.3.1 Coverglass. The instrument coverglass and any other transparent element between the coverglass and dial shall be coated with a reflection reducing film in accordance with MIL-C-675 or MIL-C-14806 as specified in the applicable instrument specification.
3.3.2 Lamps. When any portion of helium is used in the filling medium of the instrument, only MS21376, MS27569, MS27570-8515AS15, MS27570-1191AS15, MS27571-
6809AS15, or MS27571-6808AS15 lamps may be used. If helium is not used or if a non- hermetically sealed case is used, the MS25237-328AS10, MS24367-715AS15, MS24367-
713AS15, MS24515-718AS15 lamps may be used in addition to the above lamps. Any lamp selected shall be used throughout the system.
3.3.2.1 Lamp location. Lamps may be accessible either from the outside of the instrument or contained within the instrument case. Where practicable, lamps shall be removable without opening the case. In-flight replacement will not be required. Where applicable instrument specification required hermetic sealing, lamps need not be contained within the seal.
3.3.2.2 Lamp circuit. The lamp circuit shall be designed to operate from a 5.0V 400-Hz power system. All lamps shall be connected in parallel. In all applications, the circuit shall terminate in two pins which shall be used solely for the lamp circuit. Resistors or transformers shall not be used within the instrument to change to voltage applied to the lamp terminals. (Wiring between the two lighting terminals on the connector and the lamp socket or terminals shall be of sufficient size to prevent any appreciable voltage drop in the wiring.)
2
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business