1、Comments, suggestions, or questions on this document should be addressed to Defense Logistics Agency - Aviation, ATTN: DLA 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
2、this address information using the ASSIST database at https:/assist.daps.dla.mil/. AMSC N/A FSC 6610 INCH-POUND MIL-DTL-6839E 22 July 2011 SUPERSEDING MIL-DTL-6839D 30 October 2007 DETAIL SPECIFICATION INDICATOR, POSITION, LANDING GEAR Inactive for new design after 2 March 1999. This specification i
3、s approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers requirements for individual 28-volt direct current (VDC) electrical landing gear position indicators. 1.2 Classification. The landing gear position indicators are of the fol
4、lowing types as specified (see 6.2). Type I - Lusterless white dial markings (MS27403-1) Type II - Fluorescent luminescent dial markings (MS27403-2) 1.3 Part or identifying number (PIN). The PIN to be used for landing gear position indicators acquired to this specification is shown in MS27403. MS 27
5、403 - X 1 = Type I - Lusterless white dial markings 2 = Type II - Fluorescent luminescent dial markings Specification number Prefix for military specification Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 2 2. APPLICABLE DOCUMENTS 2.1
6、 General. The documents 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 compl
7、eteness of this list, 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 and standards. The following specifications and standards
8、 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. FEDERAL STANDARDS FED-STD-595/37875 - Miscellaneous, Flat or Lusterless FED-STD-595/37038 - Miscellaneous, Flat or Lusterless DEPAR
9、TMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5541 - Chemical Conversion Coatings on Aluminum and Aluminum Alloys. MIL-S-7742 - Screw Threads, Standard, Optimum Selected Series: General Specification for. MIL-A-8625 - Anodic Coatings for Aluminum and Aluminum Alloys. MS27403 - Indicator, Position, Landing
10、 Gear, 28 Volt DC. MS33558 - Numerals and Letters, Aircraft Instrument Dial, Standard Form of. MIL-DTL-83488 - Coating, Aluminum, High Purity. DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property. MIL-STD-810 - Environmental Engineering Considerations and La
11、boratory Tests. MIL-STD-889 - Dissimilar Metals. MIL-STD-31000 - Technical Data Packages. (Copies of these documents are available at https:/assist.daps.dla.mil/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) Provided by IHSNot for Res
12、aleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 3 2.2.2 Other government documents and drawings. The following other government documents and drawings form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these do
13、cuments are those cited in the solicitation or contract. STANDARDIZATION DOCUMENTS SD-6 - Provisions Governing Qualification. (Copies of this document are available at https:/assist.daps.dla.mil/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111
14、-5094.) 2.3 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 (except for related specification sheets), the text of this document takes precedence. Nothing in this document, however, su
15、persedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Specification sheet. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheet. In the event of any conflict between the requireme
16、nts of this specification and the specification sheet, the latter shall govern. 3.2 Qualification. Landing gear position indicators furnished under this specification shall be products that are authorized by the qualifying activity for listing on the applicable qualified products list before contrac
17、t award (see 4.3 and 6.3). 3.3 Standard parts. Except as allowed in 3.4, military standard (MS) or Air Force/Navy (AN) standard parts shall be used where they suit the purpose. They shall be identified on the drawings by their part numbers. 3.4 Commercial parts. Commercial utility parts such as scre
18、ws, bolts, nuts, or cotter pins having suitable properties may be used where there are no suitable standard parts provided: a. They can be replaced by the standard parts (MS or AN) without alteration. b. The corresponding standard part numbers are referenced in the parts list and if practical, on th
19、e contractors drawings. 3.5 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the operational and maintenance requirements and promotes e
20、conomically advantageous life cycle costs. 3.6 Materials. Materials shall conform to the applicable specifications and shall be specified herein. Materials for which there are no applicable specifications, or that are not specifically described herein, shall be of the best quality, of the lightest w
21、eight, and suitable for the purpose intended. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 4 3.6.1 Fungus-proof materials. Materials that are nutrients for fungi shall not be used where it is practical to avoid them. Where used and n
22、ot hermetically sealed, they shall be treated with a fungicidal agent acceptable to the contracting activity. 3.6.2 Metals. Metals shall be of a corrosion-resistant type or suitably treated to resist corrosion due to conditions likely to be encountered in storage or normal service life. 3.6.2.1 Diss
23、imilar metals. Dissimilar metals as defined in MIL-STD-889 shall not be used in intimate contact with each other unless suitably protected against electrolytic corrosion by means of protective coating. 3.6.3 Non-magnetic materials. Non-magnetic materials shall be used for all parts of the instrument
24、 except where magnetic materials are essential. 3.6.4 Corrosive fumes. The materials, as installed and under normal operating conditions, shall not liberate gases or fumes that will result in corrosion that will cause malfunction of equipment or discoloration of dials. 3.7 Design and construction. T
25、he indicator shall be in accordance with MS27403. The case shall be of nonferrous low density material and shall be finished in durable dull black in accordance with FED-STD-595 color number 37038. The indicator shall be constructed so that no part will work loose in service and shall be built to wi
26、thstand the strains, jars, vibration, and other conditions incident to shipping, storage, installation, and service without failure. 3.7.1 Dial indication. The indicator shall display the landing gear position by means of moveable tabs. The dimensions and appearance of the tabs shall conform to the
27、three position indications shown in figure 1. The wheel image shall be positioned at the top of the dial drum and the letters “UP“ shall be positioned at the bottom of the dial drum. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 5 3.7
28、.2 Power. The indicator shall be designed for operation on 28 VDC. The current required for each operating circuit shall not exceed 0.03 ampere. Resistors shall not be used to control power consumption. 3.7.3 Wiring. The indicator shall be wired so that the receptacle B terminal is common and positi
29、ve. The circuit through terminal A shall activate the “UP“ tab and terminal C shall activate the wheel tab. 3.7.4 Electrical receptacle. The receptacle shall be protected from corrosion. The receptacle shall be located as shown on MS27403, except that it may be moved not more than 0.1875 inch off th
30、e centerline of the indicator. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 6 3.7.5 Reinforcement. The inside of the case around each connection shall be of sufficient strength to prevent damage to the case when the connections are t
31、ightened during installation of the indicator. 3.7.6 Hermetically sealed case. The case shall provide a hermetically sealed enclosure for the internal mechanism. The hermetic sealing shall be accomplished so that the seal will not be dependent upon materials that will be affected by the action of an
32、y atmosphere to which the indicator may be subjected. 3.7.6.1 Helium pressure. The case shall be filled with helium of at least 98 percent purity, free from dust particles, and containing not more than 0.006 milligrams of water vapor per liter (dew point -65 C) at the filling pressure. The absolute
33、pressure of the helium within the case shall be approximately 1 atmosphere. 3.7.7 Marking. The top side of the case shall be marked “THIS END UP“ to facilitate proper mounting of the indicator. The marking, “THIS END UP“, along with an arrow pointing toward the top of the case, may be placed on each
34、 side of the case in lieu of the top. 3.7.8 Cover glass. The cover glass shall be clear and free from flaws that interfere with normal reading of the indicator. The thickness of the glass shall be suitable for the purpose and shall not exceed 0.047 inch. The distance between the inside surface of th
35、e cover glass and the arc of the dial shall not exceed 0.0312 inch. 3.8 Performance. The indicator shall be capable of satisfactory operation when subjected to the following conditions: a. Temperatures ranging from -54 C to 71 C. b. Exposure to salt-sea atmosphere. c. Vibration incident to service u
36、se. d. Shock forces of 100 g. e. Thermal shock. f. Immersion in a deaerated liquid without leaking. 3.9 Interchangeability. All parts having the same manufacturers part number shall be functionally and dimensionally interchangeable. The drawing number requirements of MIL-STD-31000 shall govern chang
37、es in the manufacturers part numbers. 3.10 Markings. 3.10.1 Dial markings. All markings shall be durable enough to withstand the usage encountered in service. Lettering style and size shall be as specified in figure 1. 3.10.2 Dial marking material. Type I indicator markings shall be in a white flat
38、or lusterless material matching FED-STD-595 color number 37875. Type II indicator markings shall be fluorescent-luminescent material. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 7 3.10.3 Dial background color. The background of the
39、dial and all other markings not otherwise specified shall be finished in flat or lusterless black matching FED-STD-595 color number 37038. 3.11 Weight. The weight of the completely assembled indicator, without the mounting screws, shall not exceed 2.5 ounces. 3.12 Screw threads. Unless otherwise spe
40、cified herein, the threads of all machine screws 0.060 inch or larger in diameter shall conform to MIL-S-7742. 3.13 Finishes and protective coatings. 3.13.1 Aluminum alloy parts. Aluminum alloy parts shall be covered with an anodic film conforming to MIL-A-8625, except as follows: a. Dials, small ho
41、les, and case inserts need not be anodized. b. Aluminum alloys that do not anodize satisfactorily shall be coated with a chemical film in accordance with MIL-DTL-5541. c. Where the primary purpose of the treatment is to provide a suitable paint base, chemical treatments in accordance with MIL-DTL-55
42、41 may be used in lieu of anodizing. d. Castings containing non-aluminum alloy integral inserts may be treated with a chemical film in accordance with MIL-DTL-5541 in lieu of anodizing. e. When abrasion resistance is a factor, chemical films in accordance with MIL-DTL-5541 shall not be used in lieu
43、of anodizing. f. Parts contained within hermetically sealed enclosures are considered to be suitably protected without anodizing or plating. 3.13.2 Steel parts. Steel parts shall be coated with ion vapor deposited aluminum, where practicable, in accordance with MIL-DTL-83488, type I or type II, as a
44、pplicable, and of a class that is adequate to achieve the degree of protection required. Other protective coating may be used in lieu of MIL-DTL-83488 if demonstrated to be satisfactory and approved by the contracting officer. Cadmium plating must be avoided when satisfactory alternative processes c
45、an be used. 3.14 Identification of product. A nameplate shall be securely attached to the outside of the case and shall be legibly and durably marked in accordance with MIL-STD-130. 3.15 Workmanship. The indicator, including all parts and accessories, shall be constructed and finished in a thoroughl
46、y workmanlike manner. Particular attention shall be given to neatness and thoroughness of soldering, marking of parts and assemblies, and freedom of parts from burrs and sharp edges. 3.16 Installation. 3.16.1 Mounting screws. The contractor shall furnish the required mounting screws and lock washers
47、 to install the indicator. Screws shall be number 6-32 round head, brass machine Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6839E 8 screws, NC-2, with a durable dull black finish and of the proper length to permit mounting on a panel 0.1
48、25 inch thick. 3.16.2 Envelope. An envelope containing the required screws and lock washers shall be furnished with each indicator. The face of the envelope shall be marked to indicate the contents. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are c
49、lassified as follows: a. Qualification inspection (see 4.3). b. Conformance inspection (see 4.4). 4.2 Inspection conditions. Except where otherwise specified, all inspections shall be performed in accordance with the test conditions specified in 4.2.1 through 4.2.4. 4.2.1 Standard atmospheric conditions. Whenever the pressure and temperature are not specified, the test shall be made at
