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 there
2、from, 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 2017 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/AS5714A AEROSPACE STANDARD AS5714 REV. A Issued 2017-03 Revised 2017-08 Superseding AS5714 Mini
5、mum Performance Standard for Parts 23, 27, and 29 Aircraft Wheels, Brakes, and Wheel and Brake Assemblies RATIONALE This document defines the minimum performance standard for TSO-C26e for wheels and brakes on Parts 23, 27, and 29 aircraft with either hydraulic or electric actuation. This also includ
6、es requirements for Accelerate-stop tests for Commuter category aircraft and jets over 6000 pounds. TABLE OF CONTENTS 1. SCOPE 3 1.1 Application . 3 1.2 Composition of Equipment 3 2. REFERENCES 3 2.1 Applicable Documents 3 2.2 Definitions and Abbreviations 3 2.2.1 Wheel Definitions 3 2.2.2 Hydraulic
7、ally Actuated Brake Definitions . 4 2.2.3 Electrically Actuated Brake Definitions 4 2.2.4 Common Definitions 5 3. GENERAL DESIGN SPECIFICATIONS 7 3.1 Airworthiness . 7 3.2 Fire Protection . 7 3.3 Design . 7 3.3.1 Lubricant Retainers . 7 3.3.2 Removable Flanges 7 3.3.3 Water Seal 7 3.3.4 Burst Preven
8、tion 7 3.3.5 Wheel Rim and Inflation Valve 8 3.3.6 Brake Piston Retention 8 3.3.7 Wear Indicator . 8 3.3.8 Wheel Bearings . 8 3.3.9 Dissimilar Materials . 8 3.3.10 Brake Release and Wear Adjustment . 8 3.3.11 Insulation Resistance 8 3.3.12 Dielectric Strength . 8 3.3.13 Bonding, Grounding, and Guard
9、ing . 8 SAE INTERNATIONAL AS5714A Page 2 of 19 3.4 Construction 8 3.4.1 Castings 9 3.4.2 Forgings 9 3.4.3 Bolts and Studs . 9 3.4.4 Environmental Protection 9 3.4.5 Magnesium Parts 9 3.4.6 Rivets and Bolts 9 3.4.7 Steel and Aluminum Parts . 9 3.4.8 Bearing and Braking Surfaces 9 4. MINIMUM PERFORMAN
10、CE UNDER STANDARD TEST CONDITIONS 9 4.1 Introduction 9 4.2 Wheel Tests 9 4.2.1 Radial Load Test . 10 4.2.2 Combined Radial and Side Load Test 11 4.2.3 Wheel Roll Test . 12 4.2.4 Overpressure Test 12 4.2.5 Diffusion Test 12 4.3 Wheel and Brake Assembly Tests 12 4.3.1 General 12 4.3.2 Design Landing S
11、top Test . 13 4.3.3 Accelerate-Stop Test for Commuter Category Aircraft and Jets Over 6000 Pounds 13 4.3.4 Structural Torque Test 15 4.3.5 Wheel to Brake Clearance Test 15 4.4 Hydraulically Actuated Brake Tests . 16 4.4.1 Yield and Overpressure Tests . 16 4.4.2 Endurance Test . 16 4.4.3 Piston Reten
12、tion Test 17 4.4.4 Leakage Tests . 17 4.5 Electrically Actuated Brake Tests 17 4.5.1 Limit and Ultimate Load Test 17 4.5.2 Endurance Test . 17 4.5.3 Brake Assembly Integrity . 17 5. DATA REQUIREMENTS . 18 5.1 Required Data . 18 5.1.1 Wheel and Brake Assembly Ratings . 18 5.1.2 Weight . 18 5.1.3 Hydr
13、aulic Fluid . 18 5.1.4 Voltage and Current Supply Limitations 18 5.1.5 Electric Brake Analysis and/or Substantiating Data 19 5.1.6 Test Report . 19 5.1.7 Component Maintenance Manuals . 19 6. NOTES 19 6.1 Revision Indicator 19 Figure 1 Accelerate-stop and park test sequence for commuter category air
14、craft and jets over 6000 pounds 14 SAE INTERNATIONAL AS5714A Page 3 of 19 1. SCOPE This SAE Aerospace Standard (AS) prescribes the Minimum Performance Standards (MPS) for wheel, brake, and wheel and brake assemblies to be used on aircraft certificated under 14 CFR Parts 23, 27, and 29. Compliance wi
15、th this specification is not considered approval for installation on any aircraft. 1.1 Application Compliance with this minimum specification by the TSO applicant is required as a means of assuring that the equipment will have the capability to satisfactorily perform its intended function(s). NOTE:
16、Certain performance capabilities may be affected by aircraft operational characteristics and other external influences. Consequently, anticipated aircraft braking performance should be verified by aircraft testing. 1.2 Composition of Equipment The words “equipment” or “brake assembly” or “wheel asse
17、mbly” or “wheel and brake assembly” as used in this document, include all components that form part of the particular unit. For example, a wheel assembly typically includes a hub or hubs, bearings, flanges, drive bars, heat shields, and fuse plugs. A hydraulically actuated brake assembly typically i
18、ncludes a backing plate, torque tube, cylinder assemblies, pressure plate, wear pin, heat sink, and other axle mounted components integral to the braking activity. Also as an example, an electrically actuated brake assembly typically includes a backing plate, torque tube, electro- mechanical actuato
19、rs, pressure plate, wear indicator, heat sink, and other axle mounted components integral to the braking activity. It should not be inferred from these examples that each wheel assembly and brake assembly will necessarily include either all or any of the above example components; the actual assembly
20、 will depend on the specific design chosen by the TSO applicant. For the purpose of this specification, the interface boundaries of the equipment are the wheel and brake attachments to the landing gear and the electrical connectors to the aircraft brake control system. The aircraft brake control sys
21、tem is a reference to any equipment related to the control of wheel braking that is not assembled to the brake on axle and provides either hydraulic energy to the hydraulic actuators or electrical energy to the Electro Mechanical Actuators (EMAs) and/or monitors sensors mounted in or on the brake as
22、sembly. This may also include hydraulic lines and fittings or wiring and connectors as applicable, if not integral to the brake. 2. REFERENCES 2.1 Applicable Documents There are no referenced publications specified herein. 2.2 Definitions and Abbreviations 2.2.1 Wheel Definitions 2.2.1.1 L - WHEEL R
23、ATED RADIAL LIMIT LOAD L is the wheel rated maximum radial limit load in 4.2.1. 2.2.1.2 S - WHEEL RATED STATIC LOAD S is the maximum static load (see 14 CFR 23.731(a), 27.731(b), and 29.731(b). SAE INTERNATIONAL AS5714A Page 4 of 19 2.2.1.3 TSWR - WHEEL RATED TIRE TYPE(S) AND SIZE(S) TSWR is the whe
24、el rated tire type(s) and size(s) defined for use and approved for installation on the wheel, normally by the aircraft manufacturer. 2.2.1.4 TTWT - SUITABLE TIRE FOR WHEEL TEST TTWT is the wheel rated tire type and size for wheel test. TTWT is the tire type and size determined as being the most appr
25、opriate to introduce loads and/or pressure that would induce the most severe stresses in the wheel. TTWT must be a tire type and size approved for installation on the wheel (TSWR), normally by the aircraft manufacturer. The suitable tire may be different for different tests. 2.2.1.5 WRP - WHEEL RATE
26、D INFLATION PRESSURE WRP is the wheel rated inflation pressure (wheel unloaded). 2.2.2 Hydraulically Actuated Brake Definitions 2.2.2.1 BROPMAX - BRAKE RATED MAXIMUM OPERATING PRESSURE BROPMAX is the maximum design metered pressure that is available to the brake to meet aircraft stopping performance
27、 requirements. 2.2.2.2 BRPMAX - BRAKE RATED MAXIMUM PRESSURE BRPMAX is the maximum pressure to which the brake is designed to be subjected (typically the nominal aircraft maximum system pressure). 2.2.2.3 BRPRET - BRAKE RATED RETRACTION PRESSURE BRPRET is the pressure to which the brake inlet pressu
28、re must be reduced to cause full piston retraction after a brake is sufficiently pressurized to extend all pistons. Applicable only when adjustment means are provided. 2.2.2.4 BRPPMAX - BRAKE RATED MAXIMUM PARKING PRESSURE BRPPMAX is the maximum parking pressure available to the brake 2.2.2.5 BRSP10
29、 - BRAKE RATED MINIMUM SLOPE PRESSURE BRSP10 = Brake Rated Minimum 10 Slope Pressure. BRSP10 is the minimum pressure required to hold the rotorcraft applications on a 10 slope at the design takeoff weight. 2.2.2.6 BRSP20 - BRAKE RATED MINIMUM 20 SLOPE PRESSURE BRSP20 is the minimum pressure required
30、 to hold the rotorcraft on a 20 slope at the design takeoff weight as used for the overpressure hydraulic brake tests of 4.4.1. 2.2.3 Electrically Actuated Brake Definitions The maximum voltage, current and power ratings refer to the maximum values for voltage, current and power at the actuators in
31、total for all the actuators in an individual brake on test. 2.2.3.1 BOP - BRAKE OFF POSITION BOP is a retracted EMA position that permits free rotation of the wheel and brake assembly after a brake application and release cycle. SAE INTERNATIONAL AS5714A Page 5 of 19 2.2.3.2 EMA - ELECTRO-MECHANICAL
32、 ACTUATOR The EMA is a subassembly of the brake that converts electrical power to brake clamping force. 2.2.3.3 IBMAX - MAXIMUM BRAKE CURRENT IBMAX is the maximum simultaneous current drawn by all the EMAs of the brake assembly in the most critical of the dynamic tests of 4.3.2 or 4.3.3 as determine
33、d by test or analysis of test results. 2.2.3.4 LBMAX - MAXIMUM BRAKE LOAD LBMAX is the maximum clamping load the brake assembly is designed to generate with maximum brake control system command under normal conditions as established by analysis or test. 2.2.3.5 LDL - BRAKE DESIGN LANDING LOAD LDL is
34、 the average of the 100 peak clamping loads generated in the brake assembly during the KEDL stop test of 4.3.2 as determined by test or analysis of test results. 2.2.3.6 LLMT - BRAKE LIMIT LOAD LLMT is the maximum clamping load the brake structure may be subjected to in its operation which would not
35、 result in permanent deformation that would prevent it from performing its intended function. 2.2.3.7 PBMAX - MAXIMUM EMA BRAKE POWER PBMAX is the maximum simultaneous power drawn by all the EMAs of the brake assembly in the most critical of the dynamic tests of 4.3.2 or 4.3.3 as determined by test
36、or analysis of test results. 2.2.3.8 PBC - PARKING BRAKE COMMAND PBC is the configuration to which the EMAs are commanded following a high energy stop as normally defined by the aircraft manufacturer associated with the parking brake applications in 4.3.3.5. 2.2.3.9 VBMAX - MAXIMUM EMA BRAKE VOLTAGE
37、 VBMAX is the maximum voltage applied to the brake assembly during the most critical of the dynamic tests of 4.3.2 or 4.3.3 as determined by test or analysis of test results. 2.2.3.10 V10 MIN - BRAKE RATED MINIMUM SLOPE VOLTAGE V10 MIN is the minimum voltage required to hold the rotorcraft on a 10 s
38、lope at the maximum aircraft design takeoff weight. 2.2.3.11 V20 MIN - BRAKE RATED MINIMUM SLOPE VOLTAGE V20 MIN is the minimum voltage required to hold the rotorcraft on a 20 slope at the maximum aircraft design takeoff weight as used for the brake tests of 4.4.1. 2.2.4 Common Definitions These def
39、initions apply to both Hydraulically Actuated and Electrically Actuated wheel and brake assemblies. 2.2.4.1 BRAKE LINING Brake lining is individual blocks of wearable material, discs that have wearable material integrally bonded to them, or discs in which the wearable material is an integral part of
40、 the disc structure. SAE INTERNATIONAL AS5714A Page 6 of 19 2.2.4.2 BRWL - BRAKE RATED WEAR LIMIT BRWL is the brake maximum wear limit to ensure compliance with 4.3.4.1 and 4.3.3.2 if applicable. 2.2.4.3 D - DISTANCE AVERAGED DECELERATION D = (Initial brakes-on speed) 2 - (Final brakes-on speed) 2)/
41、(2 (braked flywheel distance). D is the distance averaged deceleration to be used in all deceleration calculations. 2.2.4.4 DDL - RATED DESIGN LANDING DECELERATION DDL is the minimum of the distance averaged decelerations demonstrated by the wheel/brake/tire assembly during the 100 KEDL stops in 4.3
42、.2. 2.2.4.5 DRT - RATED ACCELERATE-STOP DECELERATION (FOR COMMUTER CATEGORY AIRCRAFT) DRT is the minimum of the distance averaged decelerations demonstrated by the wheel/brake/tire assembly during the KERT stops in 4.3.3. 2.2.4.6 VDL - WHEEL/BRAKE DESIGN LANDING STOP SPEED VDL is the initial brakes-
43、on speed for a design-landing stop in 4.3.2. 2.2.4.7 VRT - WHEEL/BRAKE ACCELERATE-STOP SPEED VRT is the initial brakes-on speed used to demonstrate KERT in 4.3.3. 2.2.4.8 HEAT SINK The heat sink is the mass of the brake that is primarily responsible for absorbing energy during a stop. For a typical
44、brake, this would consist of the stationary and rotating disc assemblies. 2.2.4.9 KEDL - WHEEL/BRAKE RATED DESIGN LANDING STOP ENERGY KEDL is the minimum energy absorbed by the wheel/brake/tire assembly during every stop of the 100 stop design landing stop test in 4.3.2. 2.2.4.10 KERT - WHEEL/BRAKE
45、RATED ACCELERATE-STOP ENERGY (FOR COMMUTER CATEGORY AIRCRAFT) KERT is the energy absorbed by the wheel/brake/tire assembly demonstrated in accordance with the accelerate-stop test in 4.3.3. 2.2.4.11 R - WHEEL RATED TIRE LOADED RADIUS R is the static radius at load “S” for the wheel rated tire size a
46、t WRP. The static radius is defined as the minimum distance from the axle centerline to the tire/ground contact interface. 2.2.4.12 STR - WHEEL/BRAKE RATED STRUCTURAL TORQUE STR is the maximum structural torque demonstrated in 4.3.4. 2.2.4.13 TSBR - BRAKE RATED TIRE TYPE(S) AND SIZE(S) TSBR must be
47、the tire type and size (approved for installation on the wheel (TSWR) which transfers the most kinetic energy and torque into the brake during the design landing and rejected takeoff dynamic torque tests, if applicable. SAE INTERNATIONAL AS5714A Page 7 of 19 2.2.4.14 TTBT - SUITABLE TIRE FOR BRAKE T
48、ESTS TTBT is the rated tire type and size. TTBT is the tire type and size that has been determined as being the most critical for brake performance and/or energy absorption tests. The TTBT must be a tire type and size approved for installation on the wheel (TSWR), normally by the aircraft manufactur
49、er. The suitable tire may be different for different tests. 2.2.4.15 VDL - WHEEL/BRAKE DESIGN LANDING STOP SPEED VDL is the initial brakes-on speed for a design landing stop in 4.3.2. 2.2.4.16 VRT - WHEEL/BRAKE ACCELERATE-STOP SPEED (FOR COMMUTER CATEGORY AIRCRAFT) VRT is the initial brakes-on speed used to demonstrate KERT in 4.3.3 when applicable. 3. GENERAL DESIGN SPECIFICATIONS 3.1 Airworthiness The continued airworthiness of t
