NAVY MIL-W-81752 A-1987 WINDSHIELD SYSTEMS FIXED WING AIRCRAFT GENERAL SPECIFICATION FOR《固定翼飞机挡风系统的一般技术要求》.pdf

1、M IL IT WINDSHIELD SYSTEMS, FIXED ARY SPECIFICAT MING AIRCRAFT ION t! - /!/O MIL-W-81752A(AS) 27 FEBRUARY 1987 MIL-W-81752(AS)- SUPERSEDES 23 April 1970 - GENERAL SPECIFICATION FOR This specification is approved for use within the Naval Air Systems Command, Department of the Navy, and is available f

2、or use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Sc0 e - This specification establishes the general requirements “% or the design, performance, installation, and acceptance of windshield systems in fixed wing aircraft. 2. APPLICABLE DOCUMENTS - 2.1 Government documen

3、ts - 2.1.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this specification to the extent specified herein. Unless otherwise specified, the issues of these documents shall be those listed in the issue of the Department of Defense Inde

4、x of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commanding Officer, Naval Air Engineering Center, Sy

5、stems Engineering and Standardization Department (SESD) Code 93, Lakehurst, NJ 08733-5100, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. Distribution Statement A: Approved for public release, distribution

6、is un1 iini ted. AMSC N/A FSC4560 Y. / THIS DOCUMENT CONTAINS u PAGES. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SPECIFICATIONS MILITARY MIL-G-5485 MIL-T-5842 MIL-W-6729 MIL-P-8184 MIL-1-8500 MIL-A-8860 MIL-A-8869 MIL-1-18259 MIL-E-18927 MIL-P-

7、25690 MIL-R-81261 MIL-R-81367 MIL-R-81589 MIL-P-83310 MIL-W-BL75ZA L5 m 999990b 0205050 MIL-W-81752A(AS) Glass, Laminated, Flat, Bullet-Resistant Transparent Areas, Anti-Icing, Defrosting and Defogging Systems, General Specification for Watertightness of Aircraft, Testing, General Specification for

8、Plastic Sheet, Acrylic, Modified Interchangeabil i ty and Replaceabil i ty of Component Parts for Aircraft and Missiles Airplane Strength and Rigidity, General Specification for Installation of Window Anti-Icing, De-Greasing, and Washing Systems (General Specification for) Environmental Control Syst

9、ems, Aircraft, General Requirements for Plastic, Sheets and Parts, Modified Acrylic Base, Monolithic, Crack Propagation Resistant Rain Repellent, Glass Window and Windshield, for Inflight Application Rain Repellent Fluid Application System, Aircraft Windshield Plastic Sheet, Polycarbonate, Transpare

10、nt 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Naval Air Systems Command SD-24 General Specification for Design and Construction of Aircraft Weapon Systems, Volume I - Fixed Wing Aircraft 2.1.2 Other government documents and publications - The

11、following other government documents and publications form a part of this specification to the extent specified herein. Unless otherwise specified, the issues shall be those in effect on the date of the solicitation. (Copies of specifications and standards required by contractors in connection with

12、specific acquisition functions should be obtained from the Contracting Activity or as directed by the Contracting Activity.) STANDARDS. Mi 1 i tary MIL-STD-143 MIL-STD-210 MIL-STD-470 MIL-STD-785 MIL-STD-810 MIL-STD-850 MIL-STD-882 MIL-STD-1333 MIL-STD-1472 MIL-STD-2072 Specifications and Standards,

13、 Order of Precedence for the Selection of Climatic Extremes for. Military Equipment Maintainability Program Requirements (for Systems and Equi pment Re1 i abi 1 i ty Program for Systems and Equi pment, Deve1 opment and Production Envi ronmental Test Methods and Engineering Gui del i nes Aircrew Stat

14、ion Vision Requirements for Military Aircraft Systems Safety Program Requirements Aircrew Station Geometry for Military Aircraft Human Engineering Design Criteria for Military Systems, Equipment, and Facilities Survivability, Aircraft, Establishment and Conduct of Programs for FEDERAL TEST METHODS F

15、TM-406 Plastics, Method of Testing 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-PUBLICATIONS MILITARY - MIL-SUL-544 List of Specifications and Standards (book form) 2.2 Other publications - The following document(s) form a part of this specifica

16、tion to the extent specified herein. Unless otherwise specified, the issues of the documents which are DOD adopted shall be those listed in the issue of the DODISS specified in the solicitation. Unless otherwise specified, the issues of documents not llsted in the DODISS shall be the issue sf the no

17、ngovernment documents which is current on the date of the solicitation. American Society for Testing and Materials (ASTM) Standards: ASTM F-320 Hail Impact Resistance of Aerospace Transparent Enclosures ASTM F-330 Bird Impact Testing of Aerospace Transparent Enclosures ASTM F-428 Standard Test Metho

18、d for Intensity of Scratches on Aerospace G1 ass Encl osures Transparent Parts Using the Double Exposure Method. Pl astics ASTM F-733 Standard Practice for Distortion and Deviation of ASTM 0-1003 Haze and Luminous Transmittance of Transparent ASTM D-1925 Yellowness Index of Plastics (Application for

19、 copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) 2.3 Order of precedence. In the event of a conflict between the text of tms specification and the references cited herein (except for associated detail specifications, specificat

20、ion sheets or MS standards), the text of this specification shall take precedence. Nothing in this specification, however, shall supersede applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Components 4 Provided by IHSNot for ResaleNo reproduction or n

21、etworking permitted without license from IHS-,-,-MIL-W-81752 15 W 7777906 0205053 T W 3.1.1 Selection of materials, parts and processes - The materials, parts, and processes used shall be selected primarily to accomplish the designated performance requirements. Specifications and standards for all m

22、aterials, parts, and processes which are not specifically designated herein, shall be selected in accordance with MIL-STD-143 and Mil i tary Bulletin 544 and shall require acquiring activity approval prior to use. Variations from designated items and the use of newly developed advanced material s sh

23、all require acquiring activity approval. Polycarbonate plastic shall not be used without an envi ronmental protection 1 ayer. 3.1.1.1 Non-specification material - The contractor shall be required to develop specifications for materials for which no federal, military or industry specifications exist.

24、 The specifications shall cover technical requirements, test methods, qualification, and acceptance cri teria by the acquiring activity. of the cockpit. lhe windshield shall be designed to provide clear vision for the pilot and to protect the cockpit and crew as defined both in this specification an

25、d the airplane detail specification. For tandem cockpit arrangements, consideration shall be given to providing wind blast protection for each cockpit when the canopy is jettisoned. 3.1.2 Windshield - A fixed windshield shall be provided forward 3.2 Design ambient conditions 3.2.1 O erations - The d

26、esign ambient conditions of the atmosphere “- un er whlch equipment shall remain operational shall be in accordance with the operations criteria of MIL-STD-210. withstand environmental conditions in accordance with MIL-STO-810 as specified in 4.3.4 herein. 3.2.2 Performance - Unless otherwise specif

27、ied in the contract (See 6.2.11, the design ambient conditions of the atmosphere for meeting the performance requirements of this specification.shal1 be in accordance with the 10 percent risk criteria of MIL-STD-210. If a 10 percent risk criteria is not available for a given parameter, the highest r

28、isk factor provided shall be used. 3.2.1, the entire windshield system shall be designed to operate as prescribed when subjected to the effects of aerodynamic heating. 3.2.1.1 Environmental conditions - The windshield system shall 3.2.2.1 Aero-dynamic heating - In addition to the requirements of 5 P

29、rovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I MIL-W-81752A(AS) 3.3 Aero3namic shape - The exact shape of the windshield shall include an optimum combination of all design requirements, but in no case shall the normal angle of incidence to the surf

30、ace exceed 60 degrees. The contour of the windshield shall not be so abrupt that it would create a distorted effect for binocular vision nor should there be abrupt changes in contour or thickness between adjacent transparent panels which would allow differences in angular deviation and subsequent im

31、age shift. 3.4 I_ Structural arrangement 3.4.1 Structural frames - Structural frames which affect vision from the coFl-it shall be arranged to avoid gunsight and optical landing aids viewing areas. Windshield structural frames shall also conform to the requirements of MIL-STC-850 with regard to size

32、 and vision impairment limitations. 3.4.1.1 Configuration - The use of a one pfece wrap-around type windshield for fighterlattack aircraft using a single pilot configuration is desired to maximize external vi sion. 3.4.3 Crew clearance - Crew clearance envelopes and equipment space requirements shal

33、l be coordinated with the aerodynamic shape of the windshield. 3.5 - Structural Y design 3.5.1 Nonmagnetic material - All parts within 24 inches of the magnetic compass shall be of nonmagnetic material. “ 3.5.2 Windshield Material - Material selection for windshield transparencies win be based on a

34、trade study that has evaluated, at a minimum, the following requirements as defined in the aircraft detail specification: flight envelope, cockpit arrangement, service life, ingress/egress/escape considerations, bird impact, survivability, reliability, and maintainability. When bullet resistant glas

35、s is used, it shall conform to the requirements of MIL-G-5485. When as-cast acrylic is used, it shall conform to the requirements of MIL-P-8184. When stretched acrylic is used, it shall conform to the requirements of MIL-P-25690. When polycarbonate material is used, it shall conform to the requireme

36、nts of MIL-P-83310. The material (S) selected shall be submitted to the procuring activity for approval. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-O . O a MIL-W-81752A L5 m 7777706 0205055 3 m 3.5.3 Edge attachments - Transparent plastic wind

37、shield elements may incorporate edge attachments of the laminated-type based on glass fabric or other suitable textile to reinforce the edges and restrain crack initiation. 3.5.4 Thermal effects - The transparent materials shall be securely anchored within the supports but, where feasible, shall be

38、free to expand and contract with changes in temperature and aging without distorting the structure, impairing the efficiency of the joints, or impairing the optical qualities of the panel. Consideration shall be given to the interaction between transparent components and frame caused by thermal effe

39、cts under extreme temperature conditions to insure that stress concentration in the transparent components is kept to a minimum. 3.5.5 Loads - The windshield system (transparent materials and support structure) shall be sufficiently rigid to withstand all flight loads combined with pressur.e differe

40、ntial loads from zero up to the maximum regulator tolerance. The windshield shall al so withstand all 1 andi ng and hand1 i ng 1 oads without permanent deformation. El astic deformations shall be of magnitudes which will not adversely affect proper functioning and operation. 3.5.6 Windshield attachm

41、ents - Except for electrical heating elements of thermocouples, accessories or eauiDment shall not be attached to the transparent elements of the windshield. 3.5.7 Watertightness - The windshield assembly/system shall meet the watertightness requirements of MIL-W-6729 and the aircraft detail specifi

42、cation. 3.5.8 Airtightness - Windshield design shall consider that pressurized cockpits shall be airtight within the 1 imits of MIL-E-18927 when the airplane is in flight or with engine(s) running. 3.5.9 Redundant load paths - To avoid catastrophic failures, the windshield design shall provide mu1 t

43、iDle load paths whenever practical. Each load path shall be ca,pable ofcarryin-g the anticipated applied load such that failure or malfunction of one component will not be likely to cause a more serious failure. It may be necessary to permit elastic deflection in excess of that normally desired in t

44、he event the applied load is carried by a structural system in which one-or more of the redundant load paths is inactive. The maximum amount of deflection occurring under these conditions shall not cause further failure or malfunction. 3.6 Strength requirements 7 Provided by IHSNot for ResaleNo repr

45、oduction or networking permitted without license from IHS-,-,-3.6.1 General - The windshield system shall be designed to withstand tm imposed by conditions specified in MIL-A-8860, in the detail specification of the airplane, and as modified herein. 3.6.2 Load factors - All structural designs shall

46、be in accordance with mL-A-8860, and the detail specification of the airplane, Transparent windshields and associated structure shall be designed to ensure structural conti nui ty and compati bil i ty between windshield and surrounding structure. Additional design load factors shall be used as requi

47、red to ensure safety. Deflections which may cause glass breakage or stress crazing in plastic panels shall be avoided. The size, contour, and material of the transparent windshield shall be considered in establishing a valid design load factor, 3.6.3 Pressurization loads - The windshield system shal

48、l be desinned to withstand the Dressurization loads specified in MIL-A- 8860: The design shall include the effects of continuous and cyclic pressurization loads, aerodynamic loads, and the effects of temperature and temperature differentials throughout the ground and flight envelope of the aircraft.

49、 In the event of cabin overpressurization due to a failure in the pressurization control system, the windshield system shall be designed to remain intact beyond the point where pressure is relieved by failure or deflection of some other less critical portion of the cockpit. 3.6.4 Airload distribution - The magnitude and distribution of the air1 oads used in the structural design shall be those determined by the use of acceptable anal