1、MIL-A-18717C m 999990b L948397 798 9 I INCH POUND I MI L-A-1 871 7C(AS) 20 September 1993 SUPERSEDING MIL-A-l8717B(AS) 10 September 1979 MILITARY SPECIFICATION ARRESTING HOOK INSTALLATION, AIRCRAFT This specification is approved for use by the Naval Air Systems Command, Department of the Navy and is
2、 avai lable for use by al 1 Departments and Agencies of the Department of Defense. l. SCOPE 1.1 Scope This specification covers the design, development, construction, analysis, test and documentation requirements for arresting hook installations in aircraft for which detail specifications or pertine
3、nt contractual documents require that arresting hooks be fitted. 2. APPLICABLE DOCUMENTS 2.1 Government documents 2.1.1 Specifications, standards and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specif
4、ied, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solici tation (see 6.2). SPECIFICATIONS MI LI TARY MIL-S-5002 Surface Treatments and Inorganic Coatings for Metal Surfaces
5、 of Weapon Systems Requ i remen t s For 1 General Specification For For MIL-L-6730 Lighting Equipment, Exterior, Aircraft (General MIL-D-8708 Demonstration: Aircraft Weapon Systems, MIL-A-8860 Airplane Strength and Rigidity, General Specification Beneficial comments (recommendations, additions, dele
6、tions) and any pertinent data which may be of use in improving this document should be addressed to: Commanding Officer, Naval Air Warfare Center Aircraft Division Lakehurst, Systems Requirements Department, Code SR3, Lakehurst, NJ 08733-5100, by using the self-addressed Standardizatlon Document Imp
7、rovement Proposal (DD Form 1426) appearinq at the end of this document or by letter. AMSC NIA FSC 1710 DISTRIBUTION STATEMENT A. Approved for pub1 ic release; distribution is un1 imi ted. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-8-8906 B
8、olt, Alloy Steel, Shear and Tensile (132 KSI Min FSU and 220 KSI Min FTU), 450 Deg. F, Spline Drive KSI Ftu, 450 Deg. F, (12-Spline Wrenching Element) MIL-N-8922 Nut, Self-Locking, Assembled Washer, Alloy Steel, 220 STANDARDS MILITARY MIL-STD-130 Identification Marking of U.S. Military Property MIL-
9、STD-203 Aircrew Station Controls and Displays: Location, Arrangement and Actuation of, for Fixed Wing Aircraft MIL-STD-970 Standards and Specifications , Order of Precedence for the Selection of 1( * (Unless otherwise indicated, copies of federal and military specifications, standards and handbooks
10、are available from DODSSP - Customer Service, Y Standardization Documents Ordering Desk, Bldg. 40, 700 Robbins Ave, Philadelphia, PA 19111-5094.) PUBLICATIONS Naval Air Systems Command AD-1350 - Engineering Drawings and Associated Data SD-8706 - Data and Test, Engineering; Contract Requirements for
11、Aircraft Weapon Systems Form 4200/25 - Drawings, Lists and Specifications Required (Copies may be obtained from, Commander, Naval Air Systems Command (AIR-51122E1, Washington, D.C. 20361-5110). Naval Air Warfare Center Aircraft Division Lakehurst Materi al S Process Requirements (MPR S) MPR 1067 - F
12、lame Sprayed Data Pads (Copies may be obtained from Commanding Officer, Naval Air Warfare Center Aircraft Division Lakehurst, Materials Section, Code SR46, Lakehurst, NJ 08733-50921. 2.2 Order of precedence. In the event of a conflict between the text of this document and the references cited herein
13、 (except for related associated detail specifications, specification sheets, or MS standards), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Materials. Mater
14、ials shall conform to applicable specifications and shall be as specified herein and on applicable drawings. L Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.1.1 Protective treatment. Materials shall be protected against deterioration from environ
15、mental conditions. The protective system shall be in accordance with the aircraft detai 1 specification. 3.2 Selection of specifications and standards. Specifications and standards for necessary commodities and services not specified herein shall be selected in accordance with MIL-STD-970. 3.2.1 Sta
16、ndard parts. MS and AN standard parts shall be used where riate. They shall be identified on drawinqs by their Part or Identifyins “ (PIN), (se 6.5). i aPProP Number 3.3 determ Append 3.4 be ind 3.5 des i gn Design information. Design information and suggested methods of ning the characteristics of
17、arresting hook installations are presented in x A of this specification. Nomenclature. The nomenclature of arresting hook installation parts shall cated on the figures and in the appendices of this specification. Arrestinq hook installation. The type, location, arrangement, and detail of the arresti
18、ng hook installation for each model of aircraft shall be selected consistent with satisfactory performance under al 1 design conditions and with al 1 applicable arresting gear. 3.5.1 Location. The arresting hook shall be so located that the aircraft is maintained at an attitude which ensures clearan
19、ce of all non-contact parts of the aircraft and external stores over six inch obstructions when the aircraft is subjected to the forces applied during an arrested landing. General arrangements and details of a typical carrier flight deck and its obstructions are shown on figures 1 and 2. Recommendat
20、ions for determining deck clearance are presented in Appendi x A. 3.5.2 Damage from deck pendant. The arresting hook shall be so located, or guards or supporting structure shall be provided on the aircraft where necessary to prevent the deck pendant from damaging the aircraft or from engaging parts
21、of the aircraft other than those designed for such engagement during an arrested landing. The dynamics of the deck pendant shall be investigated to ensure that this requirement is met. Table 1 shows a sampling of cable bounce height as a result of rollover from aircraft tires. Table 1 is not all inc
22、lusive and may not be representative of new aircraft/arresting hook designs with new/existing arresting gear conf i gurations. 3.5.3 Deck pendant displacement. The arresting hook shall be the designed and , located with respect to the landing gear to ensure engagement of deck pendant by the hook aft
23、er displacement by the nose wheel, main wheels or tail bumper of the aircraft passing over it. 3.5.4. Nose wheel load. The influence of the arresting hook location on the magnitude of the wheel loads shall be investigated. The design loads for the nose gear shall include those resulting from the env
24、elope of arrested landings defined in MIL-A-8860, as modified by the detail specification. Recommendations for a determining nose wheel loads-are presented-in Appendix A (see 30.5.3.3). 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-A-18717C
25、9999706 L948400 O02 m 3.5.5 Lateral movement. The arresting hook shall be free to move laterally, not less than 20 degrees to each side of the center position, to permit it to align 0 with the applied arresting forces in an “off-center“ or “skid“ landing, unless the hook is designed as a laterally r
26、igid structure to carry the specified design side 1 oad . 3.5.5.1 Centering device. A centering device shall be provided to keep the hook laterally centered against aerodynamic loads and against those lateral loads which may occur during the approach and just prior to the hook contacting the deck or
27、 a crossdeck pendant. In addition, when the hook is laterally displaced upon contact with the deck or a deck protrusion, the centering device shall return the arresting hook to an “arrestment-ready position. 3.5.6 Upward swing. The aircraft structure shall be protected from the upward swing of the a
28、rresting hook shank assembly during arrestment and retraction. 3.5.7 Shock absorber. A shock absorber shall be provided to control hook bounce. 3.5.8 Installation strength. Strength of the installation shall be as specified by MIL-A-8860. 3.6 Arresting hook desiqn. 3.6.1 Hook trail angle. The arrest
29、ing hook installation shall be designed to allow the arrestinq hook to trai 1 aft at an angle such that, when the aircraft i S at the angle of attack corresponding to the maximum lift coefficient with zero sink speed, the arresting hook will not contact the deck in a direction that wi 11 cause e dam
30、aging compression loads to be developed in the hook shank and in the aircraft structure (see Appendix A, 50.3). 3.6.2 Hook length. The arresting hook assembly shall have sufficient length to engage the deck pendant at all aircraft attitudes expected during carrier or field landing operations and abo
31、rted take-Offs, including the most cri tical atti tude defined on figure 3, except that the arresting hook length may be determined by rational analysis subject to approval by the Naval Air Systems Command (NAVAIR). NOTE: The shorter the arresting hook shank (resulting in smaller angle between the v
32、ertical and a 1 i ne drawn through the shank centerline), the greater the tendency for the aircraft to pole vault on the arresting hook system when the aircraft is moving rearward after arrestment. 3.6.3 Wear areas. The arresting hook shall be smoothly faced and made of wear-resistant material to mi
33、nimize arresting hook and deck pendant wear. The area of the shank and hookpoi nt which the pendant can contact shall contain no surface irregularities or sharp corners, and shall be coated with a wear-resistant material. A hookpoint drawing shall be provided by the contractor which defines the maxi
34、mum allowable wear and the inspection and rejection criteria. This drawing shall be submitted with drawings required by 3.10.2 (see 6.3). 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-38737C m 9999906 1948403 T49 3.6.3.1 Wear indicators. In
35、 accordance with the contractors drawing defining maximum allowable wear and inspection/rejection criteria, the hookpoint itself shall incorporate wear indicators that provide both visual and tactile information for the go/no go wear limits of the hookpoint. The hookpoint wear indicators shall provi
36、de for simple, quick inspection by aircraft squadron personnel without the use of gauges or measuring instruments. The hookpoint shall have a detachable backface wear plate that can be replaced when plate wear has reached a maximum limit. The hookpoint design shall be such that the entire backface w
37、ear will be experienced by the backface plate and none by the hookpoint itself. 3.6.4 Second pendant pick-up. The arresting hook shall be designed to prevent the possibility of picking up a second pendant after one has been engaged unless analysis of the arresting geometry shows no need. 3.6.5 Detac
38、hable hookpoint. The arresting hook installation shall have a detachable hookpoint. 3.6.6 Hookpointlshank design. The design of the hookpoint/shank shall be: (a) To preclude incorrect assembly. (b) To withstand large impact loads that act through the aft side of the hookpoint (i.e. in the opposite d
39、irection as a normal arrestment load), that may occur as a result of initial impact with the flight deck and during aircraft rollback in which the arresting hook may jam against flight deck obstructions. (c) To withstand large loads acting on the hookpoint during normal arrestments. (d To withstand
40、any possible side loads. (e Such that any loads acting on the hookpoi nt shall not be transmitted to the hookpoint/shank attaching hardware. 3.6.7 Hookpoint to shank attachment hardware. Hookpoint to shank attachment hardware shall conform to the following: a. Bolt(s) used to attach the aircraft arr
41、esting hookpoint to the hook shank shall be in accordance with MIL-B-8906. b. Nut(s) used in conjunction with the above bolt(s) shall be in accordance with MIL-N-8922. c. If a washer or other metal 1 ic materi al is required between the nut and shank or between the bolt head and shank, then thi S wa
42、sher or metallic material shall have a minimum heat treat of 180,000 psi. d. Surface treatments for the bolts, nuts, washers or other metallic material shall be in accordance with MIL-S-5002. O e. Hookpoint attachment hardware shall be solely for attaching the hookpoint to the hook shank. Its use fo
43、r collateral purposes, such as attaching bumpers or up-locks, or as shank assembly hardware, is not acceptable. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-L87L7C D 9799906 L9q8402 985 m MIL-A-18717CCAS) 3.7 Arresting hook control. Provis
44、ion shal the arresting hook by a control mechanism. The power operated. 1 be made for lowering or raising control shall be either manually or 3.7.1 Arresting hook control location. The arresting hook control shall be located in the cockpit as specified in MIL-STD-203. It shall be easily operable by
45、the pilot regardless of the position of adjustment of the pilots seat or pilots shoulder harness. 3.7.2 Arrestinq hook control desiqn. The control shall have a unique design to be readily distinguishable from adjacent cockpit controls, both by day and night in order that the pilot need not divert hi
46、s attention to locate and check the control. 3.7.3 Actuator. An actuator shall be provided to raise and lower the arresting hook. 3.7.3.1 Times for hook positioninq. The arresting hook system shall be designed to raise the hook to the stowed position within 4 seconds and to be fully extended to the
47、arrestment-ready position within 2 seconds after the cockpit control has been actuated. 3.7.4 System failure. The arresting hook control shall be designed to allow the pilot to lower the hook, and the arresting hook itself shall remain down in the event of a failure of the power system or control sy
48、stem. 3.7.5 Connection to angle of attack approach lights. The arresting hook control shall be interconnected with the angle of attack approach lights as specified in MIL-L-6730. 3.8 Shock absorber design. 3.8.1 Shock from round down. The arresting hook installation or structure shall be designed to
49、 absorb the shock loads caused by sudden extension of the arresting hook, when the aircraft passes over the forward round down of the carrier angled deck after missing a deck pendant engagement. The hook shall be assumed to extend from the “full-up“ position. 3.8.2 Hold down. The shock absorber shall include a hold down feature to minimize the bounce of the arresting hook when it strikes the deck protrusion during a carrier landing. Typical flight deck protrusions are shown on Figu
