1、Beneficial comments, (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Naval Air Engineering Center, Systems Engineering and Standardization Department, (Code 931, Lakehurst, NJ 08733-5100, by using the self-addresse
2、d Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. MIL-T-5842B Lb M 7777706 0285180 3 -/x- o/ MI L-T- 5842 B( AS 1 29 March 1985 SUPERSEDING MI L-T-5842A 13 July 1953 MILITARY SPECIFICATION TRANSPARENT AREAS ON AIRCRAFT SURFACES (WINDSH
3、IELDS AND CANOPIES), RAIN REMOVING AND WASHING SYSTEMS FOR, DE-FROSTING, DE-ICING, DEFOGGING, GENERAL SPECIFICATION FOR This specification is approved for use by the Naval Air Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defen
4、se. 1. SCOPE. 1.1 Scope. This specification establishes the requirements for systems which keep transparent areas, on aircraft surfaces (windshields and canopies), clear of ice, frost, fog, rain , salt, snow, insects, dust, gun gas residue and grease. be ground appl ied. These systems are inherent t
5、o the aircraft, but can 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Spec i fi cat ions, standards , and handbooks. Un1 es s otherwise specified, the following specifications, standards, and handbooks of the issue listed in that issue of the Department of Defense Index of Specifications a
6、nd Standards (DoDISS) specified in the solicitation form a part of this specification to the extend specified herein SPEC1 FICATIONS FEDERAL QQ-C-320 Chromi um P1 at i ng ( El e trodepos i ted) QQ-P-416 Plating, Cadmium (Eletrodeposi ted) THIS DOCUMENT CONTAINS - Requirements for Dissimilar Metals H
7、uman Engineering Design Criteria for Military Systems, Equipments and Facilities Survivability, Aircraft; Establishment and Conduct of Programs for Fittings, Installation of Flared Tube, Straight Threaded Connectors, Design Standard for 3 Provided by IHSNot for ResaleNo reproduction or networking pe
8、rmitted without license from IHS-,-,-MIL-T-5842B Lb M 777770b OL85L83 7 = MS33649 Boss, Fluid connection - Internal Straight Thread MS33656 Fitting End, Standard Dimensions for Flared Tube Connection and Gasket Seal NAVAL AIR SYSTEMS COMMAND MIL BULL 544 List of Specifications and Standards (Book Fo
9、rm) (Copies of military specifications, standards, handbooks, drawings and publications required by manufacturers in connection with specific acquisition functions should be obtained from the contracting activity or as directed by the contracting officer. 1 2.1.2 Order of precedence. In the event of
10、 a conflict between the text of this specification and the references cited herein, the text of this specification shall take precedence. 2.2 Other publications. The following document(s) form a part of this specification to the extent specified herein. The issues of the documents which are indicate
11、d as DoD adopted shall be the issue listed in the current DoDISS and the supplement thereto, if applicable. AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS: ASTM B 633 Electrodeposited Coatings of Zinc on Iron and Steel (Application for copies should be addressed to the American Society
12、for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) 3. REQUIREMENTS 3.1 Systems component. The transparent area protective systems shall be complete with all necessary components such as instruments, controls, valves, ducting, heaters, heat exchangers, pumps, electrical circuits an
13、d such other equipment that is necessary to provide the required visibility for all operating conditions of the aircraft. 3.2 Design conditions. 3.2.1 Design ambient conditions. 3.2.1.1 Operations. The design ambient conditions of atmosphere under which equipment shall remain operational shall be in
14、 accordance with the operations cri teria of MIL-STD-210, Ground and Wor Air Environments . the d-W de 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI L-T-5842B(AS 1 I 3.2.1.2 Performance. Unless otherwise specified herein, the design ambient co
15、nditions of the atmosphere for meeting the performance requirements of this specification, shall be in accordance with the 10% risk criteria of MIL-STD-210, Ground and World-Wide Air Environments. risk criteria is not available for a given parameter, the highest risk factor provided shall be used. I
16、f a 10% 3.2.1.3 Icing conditions. The atmospheric conditions for icing occurence are defined by figures 1 and 2. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-5842B Lb m 997790b 0285385 2 m ME DI AN DROPLET DIAMETER-M ICRON LIQUID WATER CON
17、TENT 4 0 12 16 20 24 PRESSURE ALTITUDE* IOOOFEET ENVELOPE OF ICING TEMPERATURE FIGURE 1. Continuous maximum atmospheric - icing conditions. 6 I I I I I I 1 1 I l i I I i I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I MIL-T-5842B 3b 7779706 03853
18、86 4 m MIL-T-5842B(AS) I IO 15 20 25 30 35 40 45 50 55. 60 “ MEAN EFFECTIVE DROP DIAMETER-MICRONS LIQUID WATER CONTENT I W a 3 L a W L 5 t- s W m 5 -a - T“O 5 IO 15 20 25 30 35 40 45 50 55 60 PRESSURE ALTITUDE J 1000 FEET ENVELOPE OF ICING TEMPERATURE FIGURE 2. Intermittent maximum atmospheric icing
19、 conditions. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI L-T-5842B(AS) 3.2.1.4 Ground operation humidity. For joint occurrence of high temperature and high humidity on the ground, the 1% curve of figure 3 shall be used in conjunction with 3.
20、2.1 1 and 10% curve of figure 3 shall be used in conjunction with 3.2.1.2. 3.2.1.5 Occupant load. A moisture output of 0.5 pounds/hour per pilot and crew and 0.3 pounds/hour per passenger shall be included in the humidity levels within occupied compartments. 3.2.2 Visi bi 1 i ty. 3.2.2.1 General. Th
21、e vision and optical qual i ties of transparent areas shall be as specified in MIL-STD-850. 3.2.2.2.1 Aircrew stations. The critical viewing areas for aircrew stations shall conform to the minimum criteria as specified in MIL-STD-850. 3.2.2.2.2 Other transparent ares. The cri ti cal viewi ng areas f
22、or other transparent areas such as sensor windows and camera windows shall be the minimum clear area required to perform the mission of the aircraft. 3.3 Selection .of material s9 parts and processes. The materials, parts and processes used shall be selected primari ly to accompl i sh the designated
23、 performance requirements. Specifications and standards for al 1 materials, parts and processes which are not specifically designated herein, shall be selected in accordance with MIL-STD-143 and Military Bulletin 544 and shall require activity approval prior to use. Variations from designated items
24、and the use of newly developed advanced materials shall require acquiring activity approval. 3.3.1 Non-specification material. The contractor shall be reauired to develop specifications for materials for which no federal, military or industry specifications exist. technical requirements, test method
25、s and acceptance cri teria for review and acceptance by the acquiring activity. The specifications shall cover 3.3.2 Metals. All metals used in the construction of the system shall be of a corrosion-resistant type or shall be suitably protected in accordance with 3.3.1.1. The use of dissimilar metal
26、s, as defined by MIL-STD-889, shall be avoided wherever practicable 3.3.2.1 Corrosion-protection. Metals which do not inherently Iiossess adeauate corrosion-resistant characteristics shall be suitably protected to resist corrosion which may recul t from such conditions as dissimilar metal combinatio
27、ns, moisture, salt spray, high temperature 8 I I I e P a Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-5842B 1b W 7779706 0185188 8 W deterioration, galvanic corrosion, as applicable. Treatments that tend to promote stress corrosion in surfac
28、es that contain residue tensile stresses shall be avoided. 3.3.2.2 be used. Maqnesium. Magnesium and magnesium alloys shall not 3.3.2.3 Insulation materials. Materials used for thermal insulation in the system established by this specification shall be of minimum weight, flameproof, corrosion resist
29、ant, impervious to flammable liquids, resistant to deleterious effects of natural and induced environments peculiar to military operations and free from odor and smoke at all times. System design disclosure will clearly indicate where insulation is required (see 3.11). 3.3.2.4 Corrosion resistant st
30、eel. 19-9DL corrosion resistant steel shall not be used. 3.3.2.5 Fluids. Any fluid used in a system established by this specification shall be compatible with the transparency surface it is used on and with any other material it may contact. The fluid shall be noncorrosive, nontoxic and nonflammable
31、. Detergents shall not be used. 3.3.3 Parts. 3.3.3.1 Standard parts. Standard parts (MS, AN or JAN) shall be used whenever they are suitable for the purpose, and shall be identified on the drawi gs by their part numbers. correspon ! ing military standard part in effect on date of invitation for bids
32、, commercial parts may be used provided they conform to all requirements of this specif i cat ion. In the event there is no suitable 3.3.3.2 Interchangeabi 1 i ty. Al 1 parts having the same part number shall be functionally and dimensionally- interchangeable as specified MIL-1-8500. n 3.3.4 Protect
33、ive treatment. 3.3.4.1 Painting. Exposed corrosion and heat resistant steel parts need not be painted. surfaces shall be type I in accordance with MIL-F-7179. Finishes and coatings for all other exposed metal 3.3.4.2 Aluminum. All aluminum and aluminum alloy parts shall be anodized in accordance wit
34、h MIL-A-8625, type II. be anodized shall receive chemical conversion treatment in accordance with Parts which cannot MIL-S-5002. 3.3 approved parts wh pl ati ng . 4.3 Plating. Unless other surface treatments are by the acquiring activity, all steel parts shall be plated. The- ch reach a temperature
35、detrimental to plating shall not require 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-5842B Lb W 99999Ob 0385387 T = 1 J I II II I1 II II II II 85 90 95 1 O0 10s 110 115 120 I RY - BULB TEMPERATURE, TI (“FI Joint values of high temperature
36、 (to 120F) and high humidity which .are equalled or exceeded 0.1, 0.5, 1, 5, 10, 20, 30, 40, 50, 60, 70 and 80 percent of the time (hours) of the-most severe month in the worlds severest joint high temperature, high humidity,environment. FIGURE 3. Joint values of high temperature and high humidity.
37、10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.3.4.4 Chromium plating. Chromium plating shall be in accordance with QQ-C-320. a rate not to exceed 0.0005 inches per hour. Plating shall be applied directly on steel, and at 3.3.4.5 Zinc plating.
38、Zinc plating shall be in accordance with ASTM B633. may exceed 600F (315C) in service. Zinc plating shall not be used on parts where the temperature 3.3.4.6 Cadmium plating. Cadmium plating shall be electrodeposited in accordance with QQ-P-416, type II, class 2, except cadmium plating shall not be u
39、sed on parts where the temperature exceeds 450F (232C) in service. 3.3.4.7 Corrosion resistant steel parts. Corrosion resistant steel parts shall not be plated unless required for dissimilar metal interface or functional reasons. They shall be passivated in accordance with MIL-S-5002. 3.3.4.8 Thread
40、s. Machine screw threads shall conform to MIL-S-7742. Pipe threads shall conform to MIL-P-7105. 3.4 Performance requirements. 3.4.1 Ice protection. In an icing environment defined by 3.2.1.3, the exterior surfaces of all critical viewing areas (3.2.2.21 shall be kept free of ice, during all steady-s
41、tate and transient operati-ons. 3.4.2 Fog and frost protection. Interior surfaces of critical viewing areas (3.2.2.2) shall be maintained free of fog and frost for all steady-state ground and flightoperating conditions. Critical viewing areas shall also be maintained free of fog and frost during max
42、imum rate descent from the operational ceiling of the aircraft in the ambient environment defined by figure 4. Preheating of the critical viewing areas, by increasing occupied compartment air temperature above normal limits, prior to descent, shall not be required in order to maintain fog free surfa
43、ces. The normal fog and frost protection provisions shall not be disabled by closure of an air conditioning package shutoff valve. 3.4.3 Rain removal system. The rain removal system for windshields shall meet the clearing requirements of MIL-R-81589 regardless of the rain removal system selected. Ra
44、in removal for other transparent areas shall clear critical viewing areas (3.2.2.21 as required to meet mission requirements of the aircraft. 3.4.4 Snow removal. Snow removal shall be removed from critical viewing areas (3.2.2.21 during ground and flight conditions. 3.4.5 Transparency cleaning syste
45、m. A cleaning system shall be provided which shall remove salt, dust, insects, gun gas residue 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T- 5 84 2B (AS ) Provided by IHSNot for ResaleNo reproduction or networking permitted without licens
46、e from IHS-,-,-MIL-T-5842B Lb m 7777906 OL85L72 T m a and grease from reciprocating engines, and any other substance which would reduce visibility of the critical viewing areas (3.2.2.2). system shall provide necessary cleaning of the critical viewing areas throughout any s.ingle mission. The cleani
47、ng 3.4.6 Emergency vision. A clear vision panel (one which is capable of being opened in flight under conditions of ice, frost, and fog), or a section of transparent areas maintained in a clear condition under conditions of ice, frost, and fog, shall provide vision to the pilot in the event of failu
48、re of the normal defroster, defogging, or anti-icing system or systems. ai rccraf t. The clear vision panel or section of transparent area maintained In i a clear condition, shall allow sufficient visibility to safely land the 3.5 Design and construction. 3.5.1 General. The transparency clearance sy
49、stems shall be designed to accompl ish the performance requirements specified herein and shall conform to the detail requirements of the applicable specifications designated. 3.5.1.1 Failure concept. Designs shall minimize failures due to thermal expansion, corrosion, decrease in material strength at elevated temperature, vibratin or any combination of these causes.
