1、 AEROSPACE INFORMATION REPORT A Guide to Landing Gear System Integration Issued 2005-12 AIR5451 RATIONALEAlthough many good documents have been produced concerning the landing gear components, there has never been a document which integrates all of the components into a landing gear system. This doc
2、ument meets that need in the form of a guide to writing an integrated landing gear system specification. TABLE OF CONTENTS 1. SCOPE 4 1.1 Purpose4 1.2 Field of Application.4 2. APPLICABLE DOCUMENTS.5 2.1 SAE Publications5 2.2 U.S. Government Publications .5 2.3 FAR and FAA Publications.5 2.4 JAR Pub
3、lications5 3. LANDING GEAR CONFIGURATION REQUIREMENTS.5 3.1 Aircraft Type, Purpose, and Use6 3.2 Landing Gear Definition .6 3.3 Landing Gear Interface Control6 3.4 Landing Gear System Build Up, Shipping and Receiving 7 4. LANDING GEAR FUNCTIONAL REQUIREMENTS 7 4.1 Taxi/Takeoff .8 Reaffirmed 2010-06S
4、AE 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 therefro
5、m, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publication may
6、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: 724-776-4970 (outside USA) Fa
7、x: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/AIR5451Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproductio
8、n or networking permitted without license from IHS-,-,-SAE AIR5451 - 2 - 4.1.1 Functional Requirements and Verification .8 4.1.2 Other Associated Functional Requirements.8 4.1.3 Regulatory Requirements 8 4.1.4 SAE Documents.9 4.2 Maneuvering 9 4.2.1 Functional Requirements and Verification .9 4.2.2
9、Other Associated Functional Requirements.11 4.2.3 Regulatory Requirements 11 4.2.4 SAE Documents.114.3 Landing 11 4.3.1 Functional Requirements and Verification .11 4.3.2 Other Associated Functional Requirements.12 4.3.3 Regulatory Requirements 12 4.3.4 SAE Documents.124.4 Braking.12 4.4.1 Functiona
10、l Requirements and Verification .12 4.4.2 Other Associated Functional Requirements.17 4.4.3 Regulatory Requirements 17 4.4.4 SAE Documents.174.5 Stability.18 4.5.1 Functional Requirements and Verification .18 4.5.2 Other Associated Functional Requirements.19 4.5.3 Regulatory Requirements 19 4.5.4 SA
11、E Documents.194.6 Gear Actuation .194.6.1 Functional Requirements and Verification .19 4.6.2 Other Associated Functional Requirements.22 4.6.3 Regulatory Requirements 22 4.6.4 SAE Documents.224.7 Landing Gear Indication.23 4.7.1 Functional Requirements and Verification .23 4.7.2 Other Associated Fun
12、ctional Requirements.26 4.7.3 Regulatory Requirements 27 4.7.4 SAE Documents.274.8 Special Purpose.274.8.1 Functional Requirements and Verification .27 4.8.2 Other Associated Functional Requirements.37 4.8.3 Regulatory Requirements 37 4.8.4 SAE Documents.385. LANDING GEAR SYSTEM INTEGRITY REQUIREMEN
13、TS 38 5.1 System Criticality38 5.1.1 Functional Hazards 395.1.2 HIRF and Lightning 395.1.3 Software.39 5.2 Failure Mode and Effects Analysis.39 5.3 Fault Tree Analysis 395.4 Common Cause Analysis.40 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or ne
14、tworking permitted without license from IHS-,-,-SAE AIR5451 - 3 - 5.5 System Safety Assessment .40 5.5.1 Wheel/Tire Failure40 5.5.2 Brake Overheat42 5.6 Electrical Power Interruptions 42 5.7 Flight Data Recorders 42 5.8 Highly Integrated Systems .43 6. LANDING GEAR PROGRAM REQUIREMENTS.43 6.1 Life C
15、ycle Cost.44 6.1.1 Recurring Cost .45 6.1.2 Concurrent Engineering .45 6.1.3 DFMA.45 6.1.4 Target Cost 46 6.1.5 Cost Tracking.46 6.1.6 Cost Containment 466.1.7 Operating Cost.46 6.1.8 Non-Recurring Cost .476.2 Weight47 6.3 Dispatch Reliability and Total Reliability 47 6.4 Maintainability 47 6.5 Cert
16、ification, Crashworthiness and Testing47 6.6 Schedule 48 6.7 Risk 48 7. LESSONS LEARNED 48 7.1 General 48 7.2 Design and Interface49 7.3 Systems Engineering .49 7.4 Structural Analysis and Performance.50 7.5 Manpower/Skills and Administration 50 7.6 Certification and Flight Test .51 8. NOTES.51 8.1
17、Key Words51 8.2 List of Acronyms.51Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5451 - 4 - 1. SCOPE: The landing gear system is a major airframe system that needs to be integrated very effi
18、ciently to minimize the penalties of weight, cost, dispatch reliability and maintenance. As the landing gear system business develops and large scale teaming arrangements and acquisitions become increasingly common, it may be desirable in some instances to procure an Integrated Landing Gear System.
19、This document provides guidelines and useful references for developing an integrated landing gear system for an aircraft and is divided into four sections: Landing Gear Configuration Requirements (Section 3) Landing Gear Functional Requirements (Section 4) Landing Gear System Integrity Requirements
20、(Section 5) Landing Gear Program Requirements (Section 6) The landing gear system encompasses all landing gear structural and subsystem elements. Structural elements include shock struts, braces, fittings, pins, wheels, tires and brakes. The subsystem elements include the retraction/extension system
21、 (both normal and alternate), the steering system, the braking system (both normal and alternate, manual and automatic), the indication systems and control systems (mechanical, hydraulic, electrical and electronic). 1.1 Purpose: The purpose of this document is to provide an airframe manufacturer or
22、procuring agency with a framework from which a specification for an Integrated Landing Gear System may be developed and to provide guidance in the development of an integrated landing gear system. This document is not intended to be an all inclusive detail design document or to duplicate other exist
23、ing SAE landing gear documents. Rather, the intent is to provide guidance in writing and managing the top-level integration requirements. 1.2 Field of Application: In the past, it has been common for airframe manufacturers to procure the landing gear and its associated systems as separate elements,
24、and to integrate these elements into the overall aircraft design. Using this approach, the airframe manufacturers have written separate specifications for each element and have assembled the landing gear from components delivered separately by different suppliers. In some instances the landing gear
25、supplier simply performs the assembly work and delivers a “dressed gear” that has been built up from components procured by the airframer. In other instances, the airframe manufacturer subcontracts the design of the landing gear, including the specification and procurement of the associated systems,
26、 to an integrator. This document includes landing gear systems for both small and large, commercial and military aircraft as well as helicopters.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AI
27、R5451 - 5 - 2. APPLICABLE DOCUMENTS: The following publications form a part of this document to the extent specified herein. The 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 co
28、nflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1 SAE Publications: Available from SAE, 400 Commonwealth Dr
29、ive, Warrendale, PA 15096-0001,Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. For applicable landing gear SAE documents see Table 1. 2.2 U.S. Government Publications: Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbin
30、s Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. For applicable landing gear U.S. Government publications see Table 2. 2.3 FAR and FAA Publications: Available from Federal Aviation Administration, 800 Independence Avenue, SW, Washington, DC 20591, Tel
31、: 866-835-5322, www.faa.gov. For a sample list of applicable landing gear FARs see Table 3. This is not meant to be a comprehensive list, and as such, each user needs to insure that the applicable documents are used for the aircraft type intended. 2.4 JAR Publications: Available from Printing and Pu
32、blication Services, Civil Aviation Authority, Greville House, 37 Gratton Road, Cheltenham GL50, 2BN, England. For a sample list of applicable landing gear JARs for large transport airplanes see Table 4. This is not meant to be a comprehensive list, and as such, each user needs to insure that the app
33、licable documents are used for the aircraft type intended. 3. LANDING GEAR CONFIGURATION REQUIREMENTS: The Landing Gear Configuration Requirements section contains the firm structural configuration of the landing gear and airframe as well as the landing gear subsystem schematics. In addition, the as
34、sociated interfaces with the airframe and other systems must be defined. The extent to which the design of the landing gear is “firm” should be specified here. It may provide the best opportunity for weight and cost avoidance if the firm gear configuration is defined as the baseline against which tr
35、ade studies are performed within the context of these requirements. The airframe manufacturer must approve any changes to the baseline landing gear configuration.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license fr
36、om IHS-,-,-SAE AIR5451 - 6 - The aircraft should have reached firm structural configuration by the time the associated landing gear contract is awarded to avoid the consequence of any major structural changes on the landing gear configuration (e.g., wing rear spar shifts can cause major changes in l
37、anding gear configuration). A firm structural configuration may be defined as a structural centerline drawing for which enough layout and sizing work has been accomplished to provide confidence that the centerlines will not change. However, this does not mean that the supplier should not have an inp
38、ut in establishing the firm structural configuration or the subsystem configuration prior to the contract award, and in fact early involvement with the supplier during this preliminary design phase is recommended.3.1 Aircraft Type, Purpose, and Use: This section should give a brief description of th
39、e aircraft and what it is to be used for. A three-view drawing of the aircraft should be included that specifies the ground contact point of each gear (maximum taxi weight, mid CG condition), and the ground angle limit (angle between floor and line tangent to bottom of unloaded tire and tail strike
40、point). This section should also specify the number of flights per day, the expected turn around time, the expected life of the aircraft, and the expected life of the landing gear between overhauls. An operational spectrum should be provided from which a landing gear fatigue spectrum can eventually
41、be generated.3.2 Landing Gear Definition: This section should define the basic landing gear geometry in the form of a landing gear centerline drawing and a landing gear three-view drawing. The centerline diagram contains all structural joints and constitutes the basis for the landing gear definition
42、. The three-view drawing should show the clearances to all major structure and aircraft loft lines. Specifically, the swept tire envelope needs to be shown in relation to the wheel well. Any systems that have been installed in the wheel well must also be defined.The tire clearance requirements shoul
43、d be defined in this section. They need to account for the grown and thrown dimensions of the tire, the tolerance stack up of all parts, and in flight deflections or generous tire envelopes.3.3 Landing Gear Interface Control: The landing gear structural interfaces to the aircraft must be specified i
44、n interface control drawings. Specifically, the trunnions, brace attach points, and actuators need to be defined.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5451 - 7 - 3.4 Landing Gear Sys
45、tem Build Up, Shipping and Receiving: This section is used to define the condition of the landing gear and systems to be delivered to the airframe manufacturer. It should include the build up of the wheels, tires, brakes, valves, actuators, transducers, lights, antennas, cabling, hydraulic and elect
46、rical lines as well as defining the loose parts (e.g., valves and electronic controllers) if these components are to be included. 4. LANDING GEAR FUNCTIONAL REQUIREMENTS: Each landing gear functional requirement will contain four sections: Functional Requirements and Verification Other Associated Fu
47、nctional Requirements Regulatory Requirements SAE Documents The Functional Requirements and Verification section is for stating each top level integration requirement as simply as possible along with the rationale for the requirement. The Verification specifies how the functional requirement will be
48、 verified in terms of inspection, analysis, demonstration, component testing, system testing, flight testing or a combination of these. A table clearly showing each of the listed requirements and the means by which it will be verified is recommended. The Other Associated Functional Requirements sect
49、ion is used to identify other functional requirements, which together with this functional requirement may influence the design solution.The Regulatory Requirements section lists those regulatory requirements (FARs, JARs, etc.) that may be associated with this Functional Requirement. At this stage the Basis of Certification should be already established and Means of Compliance (MOC) at l
