1、MIL-A-1403 66 9399906 0143127 9 = 1 - I - c-5 -8 I MIL-A-81403(AS) 15 June i967 MILITARY SPECIFICATION ALTIMETER-ENCODER, AAU-21/A This specification has been approved by the Naval Air Systems Command, Department of the Navy 1.1 This specification covers the requirement for one type of counter- drum
2、-pointer integrally lighted self-contained altimeter-encoder ( indi- cator) having a range of -1,000 to +38,000 feet and a 115V AC, 400 hertz servo driven encoder. 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invita- tion for bids or request for proposal, fo
3、rm a part of this specification to the extent specified herein. SPECIFICATIONS Federal DD-G-4 51 Military Glass , Flat and Corrugated, for Glr.zing , Mirrors and other uses MIL-P-116 MIL-C-675 MIL-E-5272 MIL-E-5400 MIL-C- 5 541 1-1-6181 MIL-S-7742 MIL-A-8625 MIL-D-OOO/ MIL-N-18307 MIL-L-25467 Preser
4、vation, Methods of Coating of Glass Optical Elements ( Anti-Reflection) Environmental Testing, Aeronautical and Associated Equipment, General Spec if icat ion for Electronic Equipment, Aircraft, General Specification for Chemical Films for Aluminum and Aluminum Alloys Interference Control Requiremen
5、ts, Aircraft Equipment Screw Threads, Standard, Optimum Selected Series: General Specification for Anodic Coatings, for Aluminum Alloys and Aluminum Drawings , Engineering and Associated Data Nomenclature and Nameplates for Aeronautical Electronic and Associated Equipment Lighting, Integral, Aircraf
6、t Instrument, General Specification for , _- -I -_/- - 7, THIS DOCUMENT CONTAINS 33- PAGES. 6 . : A- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-81403( AS) MIL-C-26482 MIL-L-27160 MIL-B-27497 STANDARDS Federal FED-STD-595 Military MIL-STD-1
7、43 MIL-STD-470 MIL-STD- 471 MIL-STD-(04 MIL-STD-781 MIL-STD-785 MIL-STD-794 MS 3113 MS 33549 MS 33558 MS 33585 MS 33649 PUBLICATION Air Force Connectors, Electric, Circular, Miniature, Quick Disconnect Lighting, Instrument , Integral, White, General Specification for Bearing, Jewel, Sapphire, or Rub
8、y Synthetic Colors Specifications and Standards , Order of Precedence for the Selection of Maintainability Program Requirements Maintainability Demonstration Electric Power, Aircraft, Characteristics, and Utilization of Reliability Tests, Exporlential Distribution Requirements for reliability progra
9、m Parts (i) Wen requesting specifications , standards , drawings , and publications refer to both title and number. Copies of this speci- fication and applicable specifications required by contractors in connection with specific procurement functions may be obtained upon application to the Commandin
10、g Officer, Naval Supply Depot, Code 105 5801 Tabor Avenue, Philadelphia, Pennsylvania 19120 (2) Copies of the FAA document may be obtained from the Federal Aviation Agency, Washington, D.C. 20553 3. REQUIREMFNTS 3.1 Qualification - The instruments furnished under this specification shall be a produc
11、t which has been tested and meets the quality assurance provisions specified herein and has been listed on or approved for listing on the applicable qualified products list. 3.2 Selection of Specifications and Standards - Specifications and stand- ards for necessary commodities and services not spec
12、ified herein shall be selected according to MIL-STD-143. 3.3 Standard General Requirements 3.3.1 Non-magnetic Materials - Non-magnetic materials shall be used for all parts except where magnetic materials are essential. which magnetic materials are required shall be reported to the procuring activit
13、y. The extent to 3.3.2 Protective Treatment - When materials are used in the construction of the altimeter-encoder that are subject to deterioration when exposed to climatic and environmental conditions likely to occur during service life, they shall be protected against such deterioration in a mann
14、er that will in no way prevent compliance with the performance requirements of the specification. The use of any protective coating that will crack, chip, or scale with age or extremes of climatic and environmental condi- tions shall be avoided. 3.3.3 Toxic and Corrosive Fumes - The materials, as in
15、stalled in the altimeter-encoder and under the conditions specified herein, shall not liberate deleterious or corrosive fumes. This shall include any fungi- cidal agents that are used. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-81403( AS)
16、3.3.4 an anodic film conforming to MIL-A-8625, except that the dial, small holes, and case inserts, need not be anodized. Parts which do not anodize satisfactorily may be coated in accordance with MIL-C-5541. Aluminum Alloy Parts - Aluminum alloy parts shall be covered with 3.3.5 Components - The el
17、ectronic and mechanical components shall be in accordance with MILE-5400. 3.3.6 altimeter shall be in accordance with MIL-B-27497. Jewel Bearings - All sapphire and ruby jewel bearings used in the 3.3.7 Threads - The threads of all machine screws shall conform to MIL-S-7742. 3.4 Design and Construct
18、ion 3.4.1 The altimeter-encoder shall include the following features : a precision all mechanical altimeter mechanism, a counter-drum-pointer altitude display, integral red I-, I ISV 400 CPS LO SUPPLY 115v400 CPS HI II 1- II 5V REDLIGHTING LIGHTING COMMON U Provided by IHSNot for ResaleNo reproducti
19、on or networking permitted without license from IHS-,-,-3.5.8 the digitizer common lead,shall be at least .O5 amps. other contacts shall be at least 115V AC at .25 amps or 28V DC at 1 amp into either resistive or relay coil load. Relay Contact Ratings - The rating of the relay contact, switching The
20、 rating of the 3.5.9 Degraded Performance - Degraded performance will be permitted for voltage transients not exceeding 0.5 seconds during normal electric operation. to the equipment. Operation shall return to normal with no resulting damage 3.5.10 Internal Vibrator - An internal vibrator shall be i
21、ncorporated into the altimeter which shall effectively decrease the friction in the mechanism. The vibrator shall be self-starting upon being energized, and shall start without being tapped or other external vibration assistance. The vibrator unit shall be capable of starting, running and or produci
22、ng vibration sufficient to meet the friction and reliability requirements specified herein for a period of 1,000 hours without failure. The design shall be such that extended use of the vibrator will not result in deposits of foreign material nor produce deleterious fumes that may result in adverse
23、effects on altimeter performance. 3.5.10.1 Power - The internal vibrator circuit shall be designed to operate normally with the power requirements of MIL-STD-704, category By for 28V d-c power. T The input current shall not exceed 90 milliampers. 3.6 Dial - The dial otherwise specified, less black C
24、olor No. shall be marked as shown in Figure 2. Unless all visible portions of thedial shall be luster- 37038 of FED-STD-595, and all markings on the dial The dimensions shall be lusterless white Color No. 37875 of FED-STD-595. of the dial markings shall be as shown on Figure 2. The dial shall be sec
25、urely fastened to the mechanism frame. 3.6.1 of the shortest graduations, and all other specified markings on the Visibility of Dial - The pointer, numerals, at least 1/32 inch dial shall be visible from any point within the frustum of a cone whose side makes an angle of 20 degrees with a perpendicu
26、lar to the dial and whose small diameter is the aperture of the case. 3.6.2 usage encountered in service. The style and proportions of numeral and letters placed on the dial shall conform to MS33558. 3.6.3 Numerals - Each numeral shall distinctly indicate the graduation to which it applies. If pract
27、icable, each numeral shall be so placed that the center mass of the numeral is on the radial line joining the appropriate graduation and the center of the dial. When several numerals are used in one group, the space between the numerals shall be approximately 1/64 inch. Markings - All markings shall
28、 be durable so as to withstand the -11- p Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-81403 (AS) 3.6.4 in lusterless white, color No. 37875 of FED-STD-595. The dimensions shall be as specified. Width of Line Height $r Length or Graduation M
29、arkings Inch - 0.015 Inch f 0.005 Finish and Dimensions - The following markings shall be finished Numerals O, 1, 2, 3, 4, 5,6,7,8,9, on counters and 0,i,2,3,4,5,6,9 on dia O. 281 O. 035 Numerals 7, 8 on dial O. i87 O. 023 100-foot graduation o. 172 O. 030 50-foot graduation 0.109 o. 015 Baro counte
30、r numerals o. 156 O. 025 ALT lettering O. 188 o. 025 IN. Hg Lettering O. 046 o. 008 100 FEET lettering o. 046 o. 008 1000 FEET lettering O. 046 o. 008 Shaded portion of pointer - - Border on altitude counter window - 0.035 The following markings shall be finished in lusterless black, color No. 37038
31、 of FED-STD-595. The dimensions shall be as specified. Width of Line Height or Length or Graduation Markings Inch 2 0.015 Inch 2 0.005 38,000 FT lettering o. 062 o. o11 CODE OFF Lettering O O93 O. O15 Unshaded portion of pointer, - dial, counters Numerals O through 9 on 100 ft. drum 0.156 AAU-21/A l
32、ettering o. 062 - O. 025 o. o11 -12- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-The background of the CODE OFF flag shall be finished in Schweit- zer Brothers Glo-Craft Red Fluorescent No. 66, formula No. 116 1548, or equivalent. The background
33、of the 100 ft drum shall be finished in lusterless grey, color No. 36440 of FED-STD-595. 3.7 integral lighting in accordance with Specifications MIL-L-25467 and MIL-L-LO to illuminate the display. operate from 5V AC or DC and shall be connected as per Figure 3. Integral Lighting - The altimeter-enco
34、der shall be provided with The lighting circuit shall 3.7.1 shall conform to DD-G-451 and shall not interfere with the readability of the instrument. It shall be properly sealed and shall be replaceable by removing the bezel. All reflecting glass surfaces shall be provided with a reflection-reducing
35、 coating that meets the requirements of MIL-C- 675, in addition to withstanding the environmental conditions specified herein, except that the following reflectance tolerances shall apply: Coverglass and lighting wedge - The coverglass and/or lighting wedges Angle of Incidence Wavelength-Millimicron
36、s O O 30 30 450-675 425-700 450-625 425-700 Percent Reflectance 0.6 absolute 0.5 average 1.0 absolute 0.5 average 3.7.2 Distance from Dial to Coverglass - The distance from dial to the innermost glass surface shall not exceed 0.250 inch. 3.8 with such necessary noise suppression features that it wil
37、l meet the limits specified for conducted and radiated radio noise in 1-1-6181. In particular, these provisions shall include adequate filters and en- closed case construction which will minimize leakage through joints, seams, and mating surfaces. The volume and weight of the filtering components re
38、quired shall be minimized by the application of proper electrical and mechanical design and construction. Radio Noise Interference - The altimeter-encoder shall be provided 3.9 specified herein under the following conditions: Performance - The instrument shall be designed to meet the performance a.
39、Temperatures - Continuous operation at temperatures ranging from -54 to +7loC and storage at temperatures ranging from -62 to +71C. b. Humidity - Relative humidity up to 100 percent. c. Altitude - Pressure altitudes ranging from -1,000 to +38,000 feet. d. -Salt Spray - Exposure to a moist salt laden
40、 atmosphere. e. Vibration - Vibration as per para. 4.7.2.7 f., Fungus - Fungus growth as encountered in tropical climates. g. Sand and Dust - Airborne sand and dust particles as encountered in desert operations. -13- - Provided by IHSNot for ResaleNo reproduction or networking permitted without lice
41、nse from IHS-,-,-MIL-A-81403( AS) h. Shock - Shock as per para. 4.7.2.9. i. Pressurization - Compartment pressurization up to an absolute j. Acceleration - Acceleration forces of 20g for a period of 30 pressure of 60 in.Hg. seconds. . 3.10 Reliability Program - The contractor shall establish a relia
42、bility assurance program in accordance with MIL-STD-785. 3.10.1 with satisfactory performance, continuously or intermittently, for a period of at least 1,000 hours without the necessity for readjustment of any controls. 3.10.2 Reliability in Mean Time Between Failure (MTBF) - The altimeter- encoder
43、shall have 1,000 hours MTBF of mean (operating) time between failures when tested and accepted as outlined under the requirements of para. 4.4.3. Operational Stability - The altimeteriencoder shall operate 3.10.3 life of 3,000 hours with reasonable servicing and replacement of parts. Parts requiring
44、 scheduM replacement shall be specified by the contractor. Longevity - The altimeter-encoder shall have a total operating 3.11 A nameplate shall be securely attached to the exterior of the case. Identification Markings shall be in accordance with MIL-N-18307. 3.12 Weight - The weight of the complete
45、 assembled altimeter-encoder, without connecting fittings and mounting screws, shall not exceed 3.75 pounds. 3.13 shall be as close as is consistent with the best shop practices. Where dimensions and tolerances may affect the interchangeability, operation, or performance of the altimeter-encoder, th
46、ey shall be held or limited Dimensions and Tolerances - Dimensions and tolerances not specified I . accordingly. 3.14 Interchangeability - All parts having the same maufacturers part number shall be directly and completely interchangeable with each other with respect to installation and performance.
47、 part numbers shall be governed by the drawing number requirements of Changes in manufacturers MIL-D-1000/1. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection - Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspec
48、tion requirements as specified herein. specified, laboratory acceptable to the Government. right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure that supplies and service conform to prescribed requirements. / Except as otherwise
49、the supplier may utilize his own facilities or any commercial The Government reserves the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-81403 66 m 777970b 0143141 3 MIL-A-81403( AS) 4.2 indicators shall be classified as follows: Classification of Inspection - Inspection of the altimeter-encoder (a) Qualification inspection: Qualifi
