1、Comments, suggestions, or questions on this document should be addressed to Defense Logistics Agency Aviation VEB, 8000 Jefferson Davis Highway, Richmond, VA 23297-5616, or e-mailed to STDZNMGTdla.mil. Since contact information can change, you may want to verify the currency of this address informat
2、ion using the ASSIST database at https:/assist.daps.dla.mil/. AMSC N/A FSC 6685 INCH-POUND MIL-DTL-5099C 30 March 2011 SUPERSEDING MIL-I-5099B 13 December 1968 DETAIL SPECIFICATION INDICATOR, CABIN AIR PRESSURE, 1-7/8 INCH DIAL, TYPE MA-1 Inactive for new design after 24 March 1999. This specificati
3、on is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the design and performance requirements for one type of pressure altitude indicator having a range of 0 to 50,000 feet. 2. APPLICABLE DOCUMENTS 2.1 General. The document
4、s listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list,
5、document users are cautioned that they must meet all specified requirements of the documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handboo
6、ks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 2 FEDERAL STANDAR
7、DS FED-STD-595/37038 - Miscellaneous, Flat or Lusterless FED-STD-595/37875 - Miscellaneous, Flat or Lusterless DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5541 - Chemical Conversion Coatings on Aluminum and Aluminum Alloys MIL-S-7742 - Screw Threads, Standard, Optimum Selected Series: General Speci
8、fication for MIL-A-8625 - Anodic Coatings for Aluminum and Aluminum Alloys MS28105 - Cover Glass, Aircraft Instrument Dial MS33558 - Numerals and Letters, Aircraft Instrument Dial, Standard Form of MS33638 - Cases, Instrument, Flange Mounted, Aircraft DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Id
9、entification Marking of U.S. Military Property MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests MIL-STD-859 - Standard Calibration Table for Aeronautical Pressure Measuring Equipment MIL-STD-889 - Dissimilar Metals MIL-STD-31000 - Technical Data Packages DEPARTMENT OF DEFE
10、NSE HANDBOOKS MIL-HDBK-454 - General Guidelines for Electronic Equipment MIL-HDBK-781 - Reliability Test Methods, Plans, and Environments for Engineering Development, Qualification, and Production (Copies of these documents are available online at https:/assist.daps.dla.mil/ or from the Standardizat
11、ion Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation
12、or contract. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 3 AEROSPACE INDUSTRIES ASSOCIATION NASM33737 - Nut, Sheet Spring, Instrument Mounting (Copies of this document are available online at www.aia-aerospace.org/ or from the Aeros
13、pace Industries Association, 1000 Wilson Boulevard, Suite 1700, Arlington, VA 22209-3928.) ASTM INTERNATIONAL ASTM C1036 - Standard Specification for Flat Glass (Copies of this document are available online at http:/www.astm.org/ or from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West
14、 Conshohocken, PA 19428-2959.) SAE INTERNATIONAL SAE AMS-QQ-P-416 - Plating, Cadmium (Electrodeposited) SAE AS5202 - Port or Fitting End, Internal Straight Thread, Design Standard (Copies of these documents are available online at http:/www.sae.org or from SAE International, 400 Commonwealth Drive,
15、Warrendale, PA 15096-0001.) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable la
16、ws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified, the contractor shall furnish sample units for first article inspection and approval (see 4.2.1 and 6.2). 3.2 Materials. Materials shall conform to applicable specifications and shall
17、be as specified herein. Materials for which there are no applicable specifications, or which are not specifically described herein, shall be of the best quality and of the lightest practicable weight suitable for the purpose intended. 3.2.1 Critical materials. Non-critical materials shall be used wh
18、ere practicable. Where the use of a critical material is essential to meet specification requirements, the material used shall be the least critical of those that are adequate for the purpose. 3.2.2 Nonmagnetic materials. Nonmagnetic materials shall be used for all parts of the indicator except wher
19、e magnetic materials are essential. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 4 3.2.3 Metals. Metals shall be of the corrosion-resistant type, or shall be suitably protected as specified herein to resist corrosion due to fuels, sa
20、lt spray, or atmospheric conditions to which the indicator may be subjected when in storage or during normal service life. 3.2.3.1 Dissimilar metals. Dissimilar metals, as defined in MIL-STD-889, shall not be used in intimate contact with each other, unless protection against electrolytic corrosion
21、is provided. 3.2.3.2 Aluminum alloy parts. Unless otherwise specified, aluminum alloy parts shall be covered with a type IC, II, or IIB anodic film conforming to MIL-A-8625, or government-approved alternate methods. The dial, small holes, threads, and case inserts need not be anodized. Aluminum allo
22、ys that do not anodize satisfactorily shall be coated with a type II, class 3 chemical film in accordance with MIL-DTL-5541. Alternate chemical film methods may be substituted with government approval. 3.2.3.3 Steel parts. Steel parts shall be cadmium-plated where practicable in accordance with SAE
23、AMS-QQ-P-416. Alternate methods of corrosion prevention may be used with government approval. 3.2.4 Protective treatment. When materials are used in the construction of the indicator that are subject to atmospheric or environmental conditions likely to cause corrosion in normal service life, they sh
24、all be protected against corrosion in a manner that will in no way prevent compliance with the performance requirements of this specification. Finishes and protective coatings which will crack, chip, or scale during normal service life, or are affected by extremes of atmospheric or environmental con
25、ditions, shall not be used. 3.2.5 Fungus-proof materials. Materials that are nutrients for fungi shall not be used where it is practicable to avoid them. Where used, they shall be treated with a fungicidal agent acceptable to the procuring activity. If the indicator case is of a hermetically sealed
26、design, then fungicidal treatment of the materials or components installed within the case will not be necessary. 3.2.6 Fumes and vapors. Materials used in the construction of the indicator shall not produce corrosive, deleterious, or toxic fumes or vapors under the conditions specified herein. 3.3
27、Design and construction. The design of the indicator shall provide a pressure- actuated mechanism. The indicator shall be so constructed that no parts will work loose in service, and it will withstand the normal shocks, vibrations, and such other conditions as are incident to service, shipping, stor
28、age, and installation without a failure. 3.3.1 Maintenance. The design shall be such as to facilitate as much as possible disassembly, repair or overhaul, service maintenance, and reassembly using those tools and items of maintenance equipment that are normally available as commercial standards. 3.3
29、.2 Case. The case shall consist of a body, a mounting flange, and a bezel ring conforming to MS33638 for the 2-inch nominal size, with an overall length of 1.750 0.125 inches. The case shall be made of nonferrous, low-density metal, uniform in texture, and shall Provided by IHSNot for ResaleNo repro
30、duction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 5 be finished with lusterless black in accordance with FED-STD-595/37038. The finishing materials shall be of a durable type to withstand usage encountered in service. 3.3.2.1 Pressure boss. The case shall have a metal boss i
31、n accordance with SAE AS5202-04 located on the rear within 0.25 inch of the vertical and horizontal centerlines, and shall not protrude more than 0.25 inch from the rear of the case. A 150 150 wire mesh corrosion-resistant filter screen shall be firmly installed. 3.3.2.2 Reinforcement. The case arou
32、nd the pressure boss shall be of sufficient strength to prevent damage to the case when the connection is tightened during installation of the indicator. 3.3.2.3 Bezel ring. The bezel ring shall be held in place by means of screws properly secured with lock washers. Provision shall be made for the r
33、eplacement of the cover glass by removal of the bezel ring. 3.3.3 Weight. The weight of the completely assembled indicator shall not exceed 0.5 pound. 3.3.4 Screw threads. Screw threads shall be in accordance with MIL-S-7742. 3.4 Dial and pointer. 3.4.1 Dial. The dial shall be securely mounted in su
34、ch a manner that it will not loosen or slip when the indicator is vibrated. If screws are used, they shall be so located that they will not interfere with the proper location of any dial marking. 3.4.1.1 Visibility of dial. The pointer, the numerals, at least 0.031 inch of the shortest graduations,
35、and all other specified markings on the dial shall be visible from any point within the frustum of a cone whose side makes an angle of 30 degrees with a perpendicular to the dial, and whose small diameter is the aperture of the case. 3.4.1.2 Dial marking. The dial shall be marked and finished as sho
36、wn in figure 1. The colors shall not change as a result of service use or subjecting the indicator to the inspections specified herein. The form of the numerals and letters shall be in accordance with MS33558. Numerals shall distinctly indicate the graduation to which each applies. If practicable, e
37、ach numeral shall be placed so that the center of area of the numeral(s) is on the radial line joining the appropriate graduation and the center of the dial. Any confusion resulting in doubt as to the graduation to which the numeral applies shall be cause for rejection. When several numerals are use
38、d in one group, the space between the numerals shall be not less than 0.016 inch. 3.4.2 Pointer. The pointer of the indicator shall be firmly attached to the mechanism, but also shall be readily removable during servicing or overhaul. The pointer form, dimensions, and finish shall conform to the req
39、uirements shown in figure 1. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 6 NOTES: 1. All dimensions are in inches. 2. Unless otherwise specified, dial tolerance 0.016; pointer tolerance 0.010; angles 0.5. 3. All dial graduations are
40、 partial radial lines. 4. Numerals and letters shall be in accordance with MS33558. 5. Thickness of pointer shall be not less than 0.010. 6. Balance end and hub of pointer shall be designed to suit conditions. Marking Height or length (0.010) Width of line or graduation (+0.005/-0.000) Material or f
41、inish1Numerals 0, 10, 20, 30, 40, 50 Lettering “CABIN PRESSURE ALTITUDE“ “X 1000 FT“ Major graduations at 0, 5, 10, 15, etc. Minor graduations Shaded portion of pointer 0.156 0.093 0.062 As shown As shown As shown 0.020 0.015 0.010 0.020 0.012 - Lusterless white in accordance with FED-STD-595/37875
42、Unshaded portion of pointer Background of dial As shown - - - Lusterless black in accordance with FED-STD-595/37038 1 Figure shown in negative view. FIGURE 1. Dial markings. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5099C 7 3.5 Cover gl
43、ass. The quality of the cover glass shall be in accordance with ASTM C1036, quality Q1, for flat sheet glass. Any flaws permitted by ASTM C1036 shall not interfere with reading of the dial. The dimensions of the cover glass shall be in accordance with MS28105. 3.5.1 Cover glass mounting. The distanc
44、e from the inner surface of the cover glass to the surface of the dial on which the marking is applied shall not exceed 0.125 inch. 3.6 Performance. The indicator shall perform satisfactorily when subjected to the tests shown in section 4 of this specification. 3.6.1 Mean-time between failures (MTBF
45、). The indicator shall have a MTBF (1- 0/1) of not less than 2,000 hours, based on a decision risk of 10 percent and a discrimination ratio (0/1) of 1.5:1. In instances where the manufacturer does not have historical data for calculation of MTBF, the procuring activity may specify reliability assura
46、nce testing (see 4.2.2). 3.7 Nameplate. A nameplate shall be securely attached to the exterior of the case and shall be marked in accordance with the requirements of MIL-STD-130, except that the national stock number shall be omitted. 3.7.1 Manufacturers part number. The manufacturers part number on
47、 the nameplate shall be identical with the manufacturers engineering production drawing number including applicable dash numbers if the drawing is tabulated and covers more than one part. 3.8 Interchangeability. All parts having the same manufacturers part number shall be directly and completely int
48、erchangeable with each other with respect to installation and performance. Changes in manufacturers part numbers shall be governed by the drawing number requirements of MIL-STD-31000. 3.9 Mounting hardware. The mounting flange shall be capable of retaining clip-in lock nuts conforming to legacy part
49、 number MS33737-11 in accordance with NASM33737. 3.9.1 Mounting lugs. Mounting lugs of the complete assembled case shall each withstand for 1 minute, without fracture, a load of 175 pounds applied along the mounting hole axis and toward the front of the instrument. 3.10 Shipping plug. A suitable shipping plug shall be screwed in the pressure insert for shipping purposes. The plug shall incorporate a
