1、MIL-D-85520 16 9977906 0206963 T MIL-D-85 5 20 (AS ) 10 March 1983 MILITARY SPECIFICATION DESIGN AND INSTALLATION OF ON BOARD OXYGEN GENERATING SYSTEMS IN AIRCRAFT, GENERAL SPECIFICATION FOR This specification is approved for use by the Naval Air Systems Command, Department of the Navy, and is avail
2、- able for use by all Departments and Agencies of the De- partment of Defense. 1. SCOPE 1.1 Scope. This specification covers the general requirements for the design and installation of on board oxygen generating systems (OBOGS) in military air- craft. 2. APPLICABLE DOCUMENTS 2.1 Government documents
3、. 2.1.1 specifications and standards. Unless otherwise specified, the following specifications and standards of the issue listed in that issue of the Department of Defense Index of Specifications and Standards (DoDISS) specified in the solicita- tion, form a part of this specification to the extent
4、specified herein. SPECIFICATIONS FEDERAL BB-N-4 1 1 - Nitrogen Technical. MILITARY MIL-E-5007 MIL-V-9050 MIL-E-18927 MIL-L-25567 MIL-G-27617 MIL-S-810 18 MIL-C-8 1302 . MIL-B-8 1365 Engine, Aircraft, Turbojet and Turbofan, General Specification for. Valve, Oxygen, Cylinder, High Pressure. Environmen
5、t Systems, Pressurized Aircraft, General Requirements for. Leak Test Compound, Oxygen Systems. Grease, Aircraft and Instrument, Fuel and Oxidizer Resistant. Survival Kit Container, Aircraft Seat, With Oxygen, General Specification for. Cleaning Compound, Solvent, Trichlorotrifluoroethane. Bleed Air
6、Systems, General Specification .for. - - Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Specifications and Standards Department (Code 93), Naval Air Engineering Center, Lakehurst, NJ 08733, by
7、using the self-addressed Standardization Document Improve- ment Proposal (DD Form 1426) appearing at the end of this document or by letter. Engineering Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- i MIL-D-85520 I6 9779906 0206964 I MIL-D-85520 (A
8、S) MIL-T-81533 - 1,1,1 Trichloroethane (Methyl Chloroform), Inhibited, MIL-H-81581 - Hose Assemblies, Breathing Oxygen and Air, General MIL-S-83427 - Survival Kit Containers, CNU-l29(V)/P and CW-l30/P. MIL-C-8552 1 - Concentrator, Oxygen. MIL-M-85522 - Monitor, Oxygen. MIL-R-85523 - Regulator, Chest
9、 Mounted, Positive Pressure. Vapor Degreasing. Specification for. STANDARDS MILITARY MIL-STD-411 Aircrew Station Signals. MIL-STD- 7 O4 - Electrical Power, Aircraft, Characteristics and MIL-STD-810 - Environmental Test Methods. MIL-STD-889 - Dissimilar Metals. Utilization of. 2.1.2 Other Government
10、documents. The following other Government document forms a part of this specification to the extent specified herein. PUBLICATIONS NAVAL AIR SYSTEMS COMMAND 01-1A-20 - Aviation Hose and Tube Manual. (Copies of specifications, standards, drawings, and publications required by manufacturers in connect
11、ion with specific acquisition functions should be obtained from the contracting activity or as directed by the contracting officer.) 2.1.3 Order of precedence. In the event of a conflict between the text of this specification and the references cited herein, the text of this specification shall take
12、 precedence. 3. REQUIREMENTS 3.1 Design. The installation of an aircraft on board oxygen generating system (OBOGS) shall comprise two major subsystems: the oxygen enriched air system (OEAS) and the airframe installed components for the bleed air and oxygen delivery system. 3.1.1 Oxygen enriched air
13、system. The oxygen enriched air system shall com- prise the oxygen concentrator, oxygen monitor and the aircrew oxygen regulator. The system shall connect with the aircrewmember personal oxygen mask and hose assembly . 3.1.2 Bleed air and oxygen delivery system. The bleed air oxygen delivery system
14、airframe installed components shall comprise, as required, bleed air shut- off valves, heat exchangers, overtemperature sensors, check valves, test connec- tions, plenums, emergency oxygen assemblies, tubing, fittings, hoses, cabling, wiring and all other items specified herein and required for a co
15、mplete instal- lation. 2 -. z Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.1.2.1 Selection of components. Components used in the bleed air and oxygen These tests shall be conducted in delivery system which operate at high temperature or high pre
16、ssure shall have been tested to indicate suitability of design. accordance with the airframe contractors acquisition specifications. frame contractors tests shall include the following tests: The air- a. Leakage tests. b. Pressure decay test. c. Burst pressure test, d. Proof pressure test. e. Pressu
17、re cycling test. f. Thermal cycling test. g. Valve “close-open-close“ cycling test. h. Flow resonance test. Burst pressure, proof pressure, pressure cycling, and flow.reconance tests shall be conducted in accordance with MIL-B-81365; 3.1.2.2 Environmental tests of bleed air and oxygen delivery syste
18、m. The bleed air and oxygen delivery system components shall have been subjected to the fol- lowing environmental tests conducted in accordance with the applicable aircraft specification, or if not provided therein, in accordance with MIL-STD-810, which- ever is more severe: a. b. C. d. e. f. g* h.
19、i. ja k. High temperature test. Low tempeature test. Humidity test. Altitude test. Salt spray test. Vibration test. Fungus resistance test, Sand and dust test. Acceleration test. Shock test. Acoust ic susceptability. 3.2 Enriched air svstems. 3 Provided by IHSNot for ResaleNo reproduction or network
20、ing permitted without license from IHS-,-,-MIL-D-5520 16 7979906 0206766 5 m 3.2.1 Systems utilizing oxygen mask. Pressurized fighter, patrol, training, attack and transport aircraft having cabin altitudes 42,000 feet and below, and the capability of descending from a maximum indicated altitude of 5
21、0,000 feet to 42,000 feet within 5 minutes after a rapid decompression, shall have an enriched air system providing concentrated oxygn to crewmembers. The aircraft shall have an enriched air system of sufficient capacity to supply the entire crew for the period of any of the specified design mission
22、s. 3.2.2 Emergency oxygen. 3.2.2.1 Escape oxygen supply. An escape oxygen supply as specified in MIL-S- 83427 or MIL-S-81018 shall be provided. The escape oxygen supply provided shall remain with the aircrewmember during his descent following aircraft abandonment. For aircraft equipped with ejection
23、 seats, provision shall be made for the auto- matic actuation of the escape oxygen supply during ejection seat operation. 3.2.2.2 OBOGS back-up oxygen supply. An emer ency corporated to provide 200 liters at 14.7 psia, 70 F to up source of oxygen in the event of an OBOGS failure. rate from that requ
24、ired in 3.2.2.1 and may be a single This supply shall be manually actuated. The interf.ace % oxygen supply shall be in- each crew station as a back- This supply shall- be sepa- source for all crewmembers. of the emergency oxygen sup- ply shall be designed in such a manner that upon actuation of the
25、emergency oxygen supply all flow of enriched air to the aircrewmember will be blocked and only emer- gency oxygen can flow to the aircrewmember. 3.3 Size and number of concentrators. The number and size of OEAS concentrator! installed on an aircraft shall be based upon the ability of the concentrato
26、r to sup. ! port the specified number of crewmembers.- Adequate space shall be provided in the- aircraft for the number of concentrators required. If two or more concentrators are installed in the aircraft, they shall be separated as much as practicable to minimize combat vulnerability. Sufficient s
27、pace shall be available to replace concentrators and perform maintenance on all parts. 3.4 System layout. Typical OROGS configurations are shown in Figures 1 through 5 for military aircraft utilizing engine bleed air as input air for the concentra- tor. number, location and application of components
28、 are determined by the aircraft characteristics and the requirements specified herein. Alternate sources of input air for the concentrator may be used, provided that the requirements of 3.6.1.1 are fulfilled, These figures represent the general arrangement of the system; the actual 3.4.1 Location. T
29、he enriched air equipment, tubing, and fittings shall be located as remotely as practicable from fuel, oil, hydraulic, electrical, radio, and insulating materials. Insofar as practical, enriched air lines shall not be grouped with lines carrying flammable fluids. Where necessary, deflector plates sh
30、all be used to keep flammable fluids away from enriched air lines, fittings, and equipment . 3.5 Major system components. 3.5.1 Concentrator. Each OBOGS installation shall incorporate an oxygen con- centrator. The concentrator shall process input conditioned air to provide a moisture reduced, low co
31、ntamination, oxygen enriched breathing gas. The remaining o Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-D-5520 Lb U 9993906 0206967 7 m M IL-D - 8 5 5 2 O (AS ) gas shall be exhausted. it shall have a resistance to air flow not to exceed that
32、 caused by a smooth base straight tube 056 inch inside diameter and four feet long. tion and performance of the concentrator is defined by MIL-C-85521. When a vent line is used to exhaust the remaining gases The design, construc- 3.5.1.1 Installation The concentrator shall be capable of being remove
33、d and replaced from the a.ircraft in less than 15 minutes. stalled, plumbing and electrical connections shall be accessible by maintenance personnel using standard hand tools. The concentrator compartment dimensions shall be determined from the concentrator dimensions provided in MIL-C-85521. With t
34、he concentrator in- 3.5.1.1.1 Preinstallation tests. The concentrator shall have passed the sea level, pressure and voltage variation operational tests of MIL-C-85521 within 30 days of installation in the aircraft. 3.5.2 Monitor. Each OBOGS installation shall incorporate an oxygen monitor. The monit
35、or provides an electrical output signal whenever the partial pressure of oxygen in the enriched air from the concentrator drops below the signal alarm range specified in MIL-M-85522. visual indicator at each crew station in the cockpit and shall initiate an audible indicator. 14IL-11-85522. pilot or
36、 designated aircrewmember while seated. The electrical output signal shall initiate a The design, construction and performance of the monitor is defined by The press-to-test plunger on the monitor shall be accessible to the 3.5.2.1 Installation. The monitor shall be capable of being removed and re-
37、placed from the aircraft in less than five minutes. With the monitor installed, plumbing and electrical connections shall be accessible to maintenance personnel using standard hand tools. To minimize the volume of the interconnecting plumbing, the monitor shall be located as close as is practical to
38、 the enriched air line. 3.5.2.1.1 Preinstallation tests. The monitor shall have passed the sea level, altitude and voltage variation operational tests of MIL-M-85522 within 30 days of installation in the aircraft. 3.5.3 Regulator. A breathing gas regulator shall be utilized for each crew- member tha
39、t will be required to- wear an oxygen mask. performance of the regulator is defined by MIL-R-85523. The design, construction and 3.5.4 Plenum. If required, the airframe shall incorporate a plenum to assure an adequate supply of breathing gas to the aircrew during periods of peak breathing demand. Th
40、e plenum shall be located near the regulator end of the aircraft plumb- ing that carries the enriched air from the concentrator to the cockpit. 3.5.5 Heat exchanger. Systems shall incorporate a heat exchanger in the air- frame, if necessary, to ensure proper cooling of the air supplied to the concen
41、- trator as specified in 3.6.1.1. The heat exchanger shall be in accordance with MIL-B-81365. 3.5.6 Overtemperature sensor. An overtemperature sensor shall be installed in the air input line for the concentrator if there is the possibility of an over- temperature condition due to a system component
42、failure. The overtemperature sen- sor shall activate a visual indicator in the cockpit to alert the pilot of an overtemperature condition in the concentrator input line. Location of the visual 5 - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-
43、D-5520 Lb W 7777906 020b9b 7 = MIL-D-855 20 (AS ) indicator(s) shall be in accordance with NIL-STD-411. 3.5.7 Shut-off valves. In systems utilizing engine bleed air, a bleed air chut-off valve which is capable of stopping bleed air flow shall be installed on the engine, located as close as possible
44、to the engine bleed air source. Each bleed air shut-off valve shall be individually activated by a cockpit mounted switch. A shut-off valve shall be provided for. each air source in systems which utilize other than engine bleed air. Engine bleed air chut-off valves shall be in accordance with MIL-B-
45、81365. 3.5.8 Check valves. 3.5.8.1 of bleed air, check valves shall be installed to preclude loss of air through an inoperative source or as a result of input air tubing failure. Engine bleed air check valves shall be in accordance with MIL-B-81365. Engine bleed air check valves. In aircraft with mo
46、re than one source 3.5.8.2 Test port check valve. A check valve shall be incorporated in the test port to prevent air from escaping in the event the closure cap is left off or comes loose. 3.5.9 Tubing. 3.5.9.1 Enriched air tubing. Tubing used in the enriched air portion of the OBOGS installation sh
47、all conform to Publication 01-1A-20 requirement for material, flaring and bending, mounting, marking and torquing for oxygen line tubing. Tubing lengths shall be kept to a minimum while allowing for expansion, concrac- tion, vibration and component replacement. 3.5.9.2 Air supply tubing. 3.5.9.2.1 T
48、ubing design. All rigid tubing shall be designed to withstand repeated simultaneous applications of pressure, temperature and velocity of air as well as thermal expansion, thermal shock, structural deflections and severe environment to the maximum values attainable under flight operating conditions.
49、 All rigid engine bleed air tubing shall be in accordance with MIL-B-81365. 3.5.9.2.2 Flexible connectors. Tubing flexible connectors shall be designed to withstand axial compression or tension, radial deflection or offset movement, or both, as may be required to prevent failure of the ducting system due to vibration or stresses caused by variations in loading or temperature. The amount of deflection (compression, tension or bending) for which the flexible connectors shall be
