1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2013 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS707CAEROSPACESTANDARDAS707 REV. CIssued 1967-10 Reaffirmed 2012-05 Revised 2013-11
5、 Superseding AS707B (R) Thermal Sensitive Inflation Pressure Release Devices for Tubeless Aircraft Wheels RATIONALEThis revision to AS707 adds references, and provides grammatical corrections and clarification of the design, interface, and test requirements. It changes terminology from “thermal rele
6、ase devices” to “fuse plugs,” consistent with FAA and government documents. TABLE OF CONTENTS 1. SCOPE 3 2. REFERENCES 3 2.1 Applicable Documents 3 2.1.1 SAE Publications . 3 2.1.2 FAA Publications . 3 2.1.3 U.S. Government Publications 4 3. DESIGN 4 3.1 Actuation Temperature . 4 3.2 Orifice 4 3.3 W
7、heel Interface . 4 3.4 Wheel Deflection . 5 3.5 Materials and Finish 5 3.6 Environment 5 4. INSTALLATION. 5 4.1 Identification 5 4.2 Location . 5 5. QUALIFICATION TESTING 5 5.1 General . 5 5.2 Release Temperature Test . 6 5.3 Low Pressure Test 6 5.4 Rate of Flow Test 6 5.5 Static Leakage Test 6 5.6
8、Extreme Temperature Leakage Test 6 5.7 Dynamic Pressure Test . 7 5.8 Dynamic Brake Test 7 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL AS707C Page 2 of 8 6. OPERATION . 7 6.1 Ins
9、pection after Activation . 7 6.2 Warning . 7 7. NOTES 8 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL AS707C Page 3 of 8 1. SCOPE The focus of this SAE Aerospace Standard (AS) is
10、the integration of thermally actuated pressure release devices, hereafter referred to as fuse plugs, with the wheel and brake assembly. It does not address the manufacturing, quality or acceptance test requirements pertaining to the production of these fuse plugs. It establishes minimum design, inst
11、allation, qualification, and operational requirements for fuse plugs which are used only in tubeless tire type aircraft braked wheels. Fuse plugs are designed to completely release the contained inflation pressure from a tubeless tire and wheel assembly when brake generated heat causes the tire or w
12、heel to exceed a safe temperature level. The objective is to prevent tire or wheel rupture due to brake generated heat that could cause an unsafe condition for personnel or the aircraft. (Reference: U.S. Department of Transportation FAA Advisory Circular No. 23-17C; Title 14, Code of Federal Regulat
13、ions (14 CFR) Part 25.735 (j); U.S. Department of Transportation FAA Advisory Circular No. 25.735-1 and U.S. Department of Transportation FAA Advisory Circular No. 25-7C.) 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document to the extent specified herein. T
14、he latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in t
15、his document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sa
16、e.org.ARP597 Wheels and Brakes, Supplementary Criteria for Design Endurance Civil Transport Aircraft ARP1493 Wheel and Hydraulically Actuated Brake Design and Test Requirements for Military Aircraft ARP1619 Replacement and Modified Brakes and Wheels 2.1.2 FAA Publications Available from Federal Avia
17、tion Administration, 800 Independence Avenue, SW, Washington, DC 20591, Tel: 866-835-5322, www.faa.gov.Technical Standard Order TSO-C26d Aircraft Wheels, Brakes and Wheel/Brake Assemblies for Parts 23, 27 and 29 AircraftTechnical Standard Order TSO-C135a Transport Airplane Wheels and Wheel and Brake
18、 Assemblies Title 14, Code of Federal Regulations (14 CFR) Part 25.731 (d) - Airworthiness Standards: Transport Category Airplanes, Wheels Title 14, Code of Federal Regulations (14 CFR) Part 25.735 (j) - Airworthiness Standards: Transport Category Airplanes, Brakes and Braking Systems U.S. Departmen
19、t of Transportation FAA Advisory Circular No. 23-17C - Systems and Equipment Guide for Certification of Part 23 airplanes and Airships U.S. Department of Transportation FAA Advisory Circular No. 25.735-1 - Brakes and Braking Systems Certification Tests and Analysis U.S. Department of Transportation
20、FAA Advisory Circular No. 25-7C - Fight Test Guide for Certification of Transport Category Airplanes Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL AS707C Page 4 of 8 2.1.3 U.S. Go
21、vernment Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/.MIL-W-5013L Wheel and Brake Assemblies Aircraft, General Specification For 3. DESIGN Fuse plug location and melting point temperatu
22、re shall be selected so that release of tire inflation pressure occurs before a tire or wheel rim temperature contrary to safe operation of the wheel and tire assembly is reached but not so low that inadvertent release occurs during normal operations including quick turnaround operation. Also, there
23、 shall be no premature release during the accelerate-stop or most severe landing conditions. (Reference: U.S. Department of Transportation FAA Advisory Circular No. 23-17C and U.S. Department of Transportation FAA Advisory Circular No. 25-7C.)3.1 Actuation Temperature The fuse plug actuation tempera
24、ture shall be selected to be consistent with permissible temperature levels for the wheel and tire, respectively, for a given aircraft application. Fuse plugs shall be designed to release consistently within 10 F (6 C) of their melting point temperature or rating at any tire inflation pressure from
25、low to rated pressure with the rated pressure adjusted for temperature rise. This melting point and tolerance includes the effects of heat and variations in rates of temperature change. It also accounts for acceptable variations in eutectic alloy chemistry including foreign materials and impurities.
26、 When the installed fuse plugs reach the selected temperature level as a result of absorbed heat, they shall completely release the contained inflation pressure of the tire. The installation shall be such that the fuse plugs function properly and consistently prior to the wheel bead seat exceeding c
27、ritical rim or tire temperatures. Upon reaching the melting point temperature, fuse plugs shall melt cleanly, at all pressures. There shall be no partial melts, or pin hole leaks. (Reference: U.S. Department of Transportation FAA Advisory Circular No. 23-17C, U.S. Department of Transportation FAA Ad
28、visory Circular No. 25.735-1 and U.S. Department of Transportation FAA Advisory Circular No. 25-7C.) 3.2 Orifice The orifice in each fuse plug shall be sufficiently large to assure decreasing tire pressure under all conditions, in particular, during the time that the wheel is being overheated. (Refe
29、rence U.S. Department of Transportation FAA Advisory Circular No. 23-17C, U.S. Department of Transportation FAA Advisory Circular No. 25.735-1 and U.S. Department of Transportation FAA Advisory Circular No. 25-7C.) The size of each orifice shall be such as to permit the tire inflation pressure to de
30、crease to 50% of its initial value in not more than 2 minutes when only one fuse plug releases.The location, number of fuse plugs and orifice size shall release tire pressure prior to tire or wheel failure resulting from temperature induced structural degradation following the maximum energy conditi
31、on(s), typically accelerate-stop and/or most severe landing stop. 3.3 Wheel Interface Although the number of fuse plugs shall be minimized to achieve maximum installation reliability, a minimum of three shall be used with consideration for as equal a circumferential spacing as possible and appropria
32、tely located to reduce the tire pressure to a safe level before any part of the wheel becomes unacceptably hot, irrespective of the wheel orientation.Consideration shall be given to the installation of the fuse plugs in the wheel at a location that minimizes the effect on fatigue life of the wheel s
33、tructure. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL AS707C Page 5 of 8 3.4 Wheel Deflection The installation and fit between the wheel and the fuse plugs shall be such as to a
34、llow for wheel deflections under all static and dynamic operating conditions while simultaneously exposed to the entire range of ambient and brake induced temperatures. The clearance and strength of the fuse plugs shall be sufficient to allow cyclic deflections of the wheel without failure, impaired
35、 function, or leakage of the fuse plugs or their associated seals at all wheel temperatures below the melting point temperature of the fuse plugs. 3.5 Materials and Finish Materials and finishes shall be of aircraft quality, and shall be electrolytically and thermally compatible with the wheel mater
36、ial. If fusible materials are used, it is desirable that they be of the eutectic type, preferably cadmium free. 3.6 Environment The fuse plugs shall be capable of withstanding the same environmental conditions as are imposed on the wheel. 4. INSTALLATION Details of installation of the fuse plugs sha
37、ll receive approval of the procuring agency. 4.1 Identification Each fuse plug shall be identified with regard to rated temperature either by part number, code number, color code, or other permanent type marking as established by the manufacturer. Although not practical for some applications, it is
38、desirable that this marking be visible for inspection with the tire installed on the wheel including under adverse environmental conditions. 4.2 Location The design and location of the fuse plugs shall be such as to permit inspection without removal of the tire from the wheel where practical. This p
39、reference for inspection without removal of the tire shall not take precedence over the need to correctly position the fuse plugs for efficient gas release per 3.3. Changing the fuse plugs with or without removal of the tire shall be a procuring agency option.The fuse plugs shall be designed and loc
40、ated so that once activated their continued operation is not impaired by the releasing gas. Restrictions around the pressure release orifice shall not cause deflation times to exceed the time required to ensure wheel integrity.If the fuse plugs expel material when they release pressure, they shall b
41、e located to assure that any expelled material will not strike personnel in the vicinity of the aircraft or any vulnerable equipment on the aircraft or the wheel and brake assemblies. The fuse plugs shall be located in such a manner that damage from normal handling does not occur. 5. QUALIFICATION T
42、ESTING 5.1 General The fuse plugs, when installed in the wheel assembly, shall be capable of satisfying the tests specified below. These tests shall be conducted and the requirements met for the purpose of demonstrating satisfactory performance of the fuse plugs. In all such tests, the fuse plugs sh
43、all function per the intended design allowing deflation at the rate described in 3.2. In addition, the fuse plugs shall be subjected to the entire wheel and brake qualification tests or equivalent tests based on the original qualification test results. (Reference: U.S. Department of Transportation F
44、AA Advisory Circular No. 23-17C and U.S. Department of Transportation FAA Advisory Circular No. 25-7C.) All tests shall meet the applicable requirements of Section 3. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without licen
45、se from IHS-,-,-SAE INTERNATIONAL AS707C Page 6 of 8 With satisfactory performance of the fuse plugs during wheel and brake qualification, and simulated field operation tests, verification by similarity to existing designs may be claimed for the performance tests of 5.2 through 5.7. When claiming si
46、milarity, due consideration shall be given to actuation temperature, wheel and brake design, fuse plug design and location, and tire inflation pressure and volume. (Reference: ARP1619.) 5.2 Release Temperature Test The wheel manufacturer shall demonstrate the effectiveness of the fuse plugs in preve
47、nting hazardous tire blowout or wheel failure. It shall be demonstrated that the fuse plugs release tire contained gas following any brake usage condition for which the wheel temperature at the bead seat reaches a maximum temperature level agreed upon for the component capabilities with the contract
48、ed suppliers. (Reference ARP1493.) The fuse plugs shall release consistently within 10 F (6 C) of their melting point temperature or rating at any tire inflation pressure from low to the rated pressure adjusted for the contained inflation gas temperature. This may be demonstrated during qualification and flight testing of the brake assemblies, typically the accelerate-stop and most severe landing stop conditions. It shall also be demonstrated that the fuse plugs will not release the tire pressure prematurely during takeoff and landing, including during quick turnaround operations. Refer
