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 2012 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:/www.sae.org/technical/standards/ARP5770 AEROSPACE RECOMMENDED PRACTICE ARP5770 Issued 2012-11 Mechanical Control
5、Design Guide RATIONALE Mechanical systems for transmitting pilot commands to flight control surfaces, secondary controls, utility controls or servo control actuators are used less as electrical command transmission is used more frequently. But, mechanical transmission of primary, secondary, utility
6、or backup commands is likely to be the appropriate choice for some aircraft of the future. There is a need of having a document which provides recommended practice for design of Mechanical Control Systems; this ARP satisfies that need. FOREWORD Mechanical controls have been used since the advent of
7、aviation to transform pilot commands into control surface deflections and secondary and utility control actuation. Mechanical controls were initially used to position control surfaces directly. (Smaller aircraft, currently being developed, use mechanical controls almost exclusively because of reduce
8、d complexity, weight and cost, and proven reliability.) But as aircraft size, speed and maneuverability were increased, the power and/or accuracy required to position a control surface increased to a level where the exclusive use of mechanical controls was inadequate. On some aircraft, the pilot for
9、ces became too high for pure mechanical control. This resulted in the introduction of servoactuation. As control requirements became more complex, modifiers were installed upstream or integral with the servoactuators to enhance controllability, maneuverability and/or ride comfort. Some of these latt
10、er mechanical control systems became relatively complex. Fly-By-Wire (FBW) and Control-By-Wire (CBW) were recognized as alternate solutions to complex mechanical controls. As electronic reliability improved, airframe company confidence in electronic control reached a level where FBW and CBW were int
11、roduced and increased in popularity. But, even on FBW and CBW controlled aircraft, mechanical controls are still utilized in a limited way as backup systems or to convert pilot commands into FBW and CBW command signals. This ARP addresses mechanical controls that are found in aircraft primary, secon
12、dary and utility control systems. These control systems typically use cables and pulleys, pushrods and cranks, and combinations of both to transmit manual pilot commands into control surface, secondary and utility control displacements. The mechanical control guidelines provided in this ARP were acc
13、umulated from inputs from a number of prime aircraft manufacturers and personal experiences of a number of control system engineers. SAE ARP5770 Page 2 of 98 TABLE OF CONTENTS 1. SCOPE 5 2. REFERENCES 5 2.1 Applicable Documents 5 2.1.1 SAE Publications . 5 2.1.2 EASA Publications 5 2.1.3 FAA Publica
14、tions . 6 2.1.4 Joint Aviation Authorities Committee Documents . 6 2.1.5 National Aerospace Standards . 6 2.1.6 Military Guide Specifications . 7 2.1.7 U.S. Government Publications 7 2.2 Abbreviations, Acronyms, Symbols 8 3. SYSTEM CONSIDERATIONS 9 3.1 Control System Classifications . 9 3.1.1 Primar
15、y Flight Control Systems (PFCS) . 9 3.1.2 Secondary Control Systems (SCS) 9 3.1.3 Utility Control Systems (UCS) . 9 3.1.4 Flight Control System Operational State Classifications 9 3.1.5 Flight Control System Criticality Classifications 10 3.2 Control System Operational Requirements 10 3.2.1 Control
16、System Redundancy 10 3.2.2 Vulnerability . 10 3.2.3 Reliability . 12 3.2.4 Control System Load Requirements . 12 3.3 System Friction and Breakout Force Calculations 16 3.4 Control System Positionability/Threshold . 23 4. CONTROL SYSTEM INSTALLATION GUIDELINES . 26 4.1 Control System Routing/Orientat
17、ion/Installation . 26 4.2 Cockpit Controls 26 4.3 Control System Stops . 26 4.4 Control System Separation and Clearances . 27 4.5 Control System Rigging Provisions 28 4.6 Cable System Installations 30 4.7 Control Pushrod Installations 33 4.8 Push-Pull Flexible Control Installations 39 4.9 Electrical
18、 Bonding . 39 4.10 Corrosion Protection . 39 4.11 Bearings and Lubrication 39 4.12 Control System Maintenance 39 5. COMPONENT DESIGN GUIDELINES . 41 5.1 Control Cable 41 5.2 Cable Tension Regulators 59 5.3 Sheaves 61 5.4 Sheave Mounting Brackets . 66 5.5 Cable Guards 68 5.6 Fairleads and Rub Strips
19、71 5.7 Cable Seals . 73 5.8 Control Pushrods and Bellcranks . 75 5.8.1 Control Pushrods 75 5.8.2 Control Pushrod Crank/Bellcrank Design . 83 5.8.3 Override Devices. 88 5.9 Bolt Selection and Installation . 89 5.10 Snap Rings 91 SAE ARP5770 Page 3 of 98 5.11 Roll Pins 92 5.12 Bearings 92 5.13 Redunda
20、nt Load Paths . 96 5.14 Threads . 96 6. CONTROL SYSTEM DESIGN DOCUMENTATION . 96 6.1 Design Diagrams 96 6.2 Design Data 97 7. NOTES 98 FIGURE 1 CHARACTERISTIC TRANSPORT AIRCRAFT ELEVATOR CONTROL SYSTEM ISOMETRIC 18 FIGURE 2 RIGGING PIN PROVISIONS 28 FIGURE 3 SINGLE SHEAR RIGGING PIN INSTALLATION - P
21、OOR DESIGN 29 FIGURE 4 DOUBLE SHEAR RIGGING PIN INSTALLATION - GOOD DESIGN 29 FIGURE 5 MISALIGNMENT IMPACT ON CABLE FRICTION . 31 FIGURE 6 PULLEY GUARD 32 FIGURE 7 CABLE AND CRANK INSTALLATION . 33 FIGURE 8 CABLE AND CRANK INSTALLATION . 33 FIGURE 9 MOTION LAYOUTS 34 FIGURE 10 PREFERRED MOTIONS - HI
22、GH PERFORMANCE JET . 35 FIGURE 11 CRANK AND PUSHROD ARRANGEMENT . 36 FIGURE 12 CONTROL SYSTEM SCHEMATIC WITH NON-LINEAR GAIN CHANGER AND SERIES TRIM ACTUATOR . 36 FIGURE 13 UNIQUE CONTROL MOTIONS 37 FIGURE 14 UNIQUE CRANK AND PUSHROD ARRANGEMENT . 37 FIGURE 15 LONG PUSHROD RUNS 38 FIGURE 16 WALKING
23、BEAM INSTALLATION 38 FIGURE 17 CARBON STEEL CABLE FRICTION AT 180 DEGREE WRAP VERSUS PULLEY AND GROOVE DIAMETER 48 FIGURE 18 CARBON STEEL CABLE FRICTION VERSUS PULLEY WRAP . 49 FIGURE 19 SHEAVE-CABLE DIAMETER RATIO EFFECT ON SERVICE LIFE 51 FIGURE 20 CABLE-SHEAVE FRICTION WITH GROOVE RADIUS = (D/2)
24、+ 0.020 in (0.050 cm) . 52 FIGURE 21 CABLE-SHEAVE FRICTION WITH GROOVE RADIUS = (D/2) + 0.036 in (0.091 cm) . 53 FIGURE 22 SIGNIFICANT CABLE TEMPERATURE ZONES . 56 FIGURE 23 CABLE TURNBUCKLE WITH LOCKING CLIPS 57 FIGURE 24 CABLE TURNBUCKLE LOCKING CLIP INSTALLATION 58 FIGURE 25 FORK CABLE TERMINAL 5
25、8 FIGURE 26 SPECIAL FORKS 59 FIGURE 27 CABLE SYSTEM WITH CTR INSTALLED . 60 FIGURE 28 DRUM GROOVE DIMENSIONS . 61 FIGURE 29 DRUM GROOVES FOR 1/8, 5/32, AND 3/16 CABLE (SEE FIGURE 28 FOR 1/16 AND 3/32 CABLE) . 62 FIGURE 30 TYPICAL DRUM CABLE TERMINATION AND GUARDS . 62 FIGURE 31 LARGE DRUM CABLE TERM
26、INATION AND GUARDS 63 FIGURE 32 PRIMARY FLIGHT CONTROL QUADRANT CABLE TERMINATION . 63 FIGURE 33 PRIMARY FLIGHT CONTROL QUADRANT CABLE TERMINATION . 64 FIGURE 34 SECONDARY CONTROL QUADRANT CABLE TERMINATION 64 FIGURE 35 PRIMARY FLIGHT CONTROL QUADRANT CABLE TERMINATION . 65 FIGURE 36 PRIMARY FLIGHT
27、CONTROL QUADRANT CABLE TERMINATION . 65 FIGURE 37 HAT SECTION PULLEY BRACKET . 67 FIGURE 38 BRACKET MOUNTED ON SLOPE 67 FIGURE 39 PULLEY MOUNTING 68 FIGURE 40 SHEAVE GUARDS . 68 FIGURE 41 TWO SHEAVE GUARDS 69 FIGURE 42 THREE SHEAVE GUARDS 69 FIGURE 43 PULLEY TO GUARD CLEARANCE . 69 FIGURE 44 QUADRAN
28、T MOUNTED GUARD 70 FIGURE 45 TYPICAL FAIRLEAD INSTALLATION 71 FIGURE 46 TYPICAL RUB STRIP INSTALLATION 72 SAE ARP5770 Page 4 of 98 FIGURE 47 TAPERED GROMMET INSTALLATION 73 FIGURE 48 EYEBALL AND FINNED CABLE SEALS 74 FIGURE 49 SIMPLE CABLE FIREWALL SEAL . 74 FIGURE 50 SINGLE LOAD PATH NON-ADJUSTABLE
29、 PUSHROD . 76 FIGURE 51 SINGLE LOAD PATH PUSHROD WITH HALF-TURN ADJUSTABLE ROD . 76 FIGURE 52 SINGLE LOAD PATH VERNIER ADJUSTABLE PUSHROD . 77 FIGURE 53 SINGLE LOAD PATH WITH BOTH ENDS ADJUSTABLE PUSHROD . 77 FIGURE 54 COMPOSITE ADJUSTABLE PUSHROD . 77 FIGURE 55 SINGLE LOAD PATH NON-ADJUSTABLE PUSHR
30、OD . 77 FIGURE 56 TYPICAL INSTALLATION OF NAS1193 POSITIVE INDEX WASHER . 78 FIGURE 57 TYPICAL INSTALLATION OF NAS513 SAFETY LOCKWASHER 79 FIGURE 58 TYPICAL INSTALLATION OF NAS559 KEY LOCK . 79 FIGURE 59 ROD END THREAD ENGAGEMENT INSPECTION METHODS . 80 FIGURE 60 DRAIN HOLE LOCATION IN SWAGED PUSHRO
31、D 81 FIGURE 61 DRAIN HOLE LOCATION IN CANTED SWAGED PUSHROD 81 FIGURE 62 DRAIN HOLES IN END FITTINGS . 82 FIGURE 63 SIDE DRAIN HOLES WITH END FITTINGS 82 FIGURE 64 SEALS . 83 FIGURE 65 BELLCRANK DESIGN GUIDELINES . 85 FIGURE 66 NON-COPLANAR BELLCRANK FEATURES 86 FIGURE 67 SELF-ALIGNING ROD END/CLEVI
32、S ARRANGEMENT 87 FIGURE 68 SELF-ALIGNING ROD END/CLEVIS ARRANGEMENT 87 FIGURE 69 CLEVIS WITH RETAINED SLIP-FIT BUSHING . 88 FIGURE 70 AVERAGE STARTING TORQUE - NO LOAD . 93 FIGURE 71 AVERAGE RUNNING TORQUE - NO LOAD . 94 TABLE 1 DESIGN REQUIREMENTS FOR ESSENTIAL FLIGHT CONTROL SYSTEMS 11 TABLE 2 14C
33、FR PART 23 AND 25 /EASA CS-23 AND -25 CONTROL SYSTEM LIMIT DESIGN LOADS 13 TABLE 3 MAXIMUM OPERATIONAL FORCES 14 TABLE 4 BREAKOUT FORCES 14 TABLE 5 MANUAL OVERRIDE FORCES . 15 TABLE 6 COMPONENT FRICTION CALCULATION 16 TABLE 7 AFBMA (ANTI-FRICTION BEARING MANUFACTURER ASSOCIATION) BEARING AVERAGE NO-
34、LOAD BREAKOUT TORQUE AT 70 F 1/ . 17 TABLE 8 CHARACTERISTIC ELEVATOR CONTROL SYSTEM COMPONENT FRICTION ANALYSIS 19 TABLE 9 CHARACTERISTIC ELEVATOR CONTROL SYSTEM COMPONENT FRICTION ANALYSIS 20 TABLE 10 CONTROL SYSTEM CLEARANCES . 27 TABLE 11 SUGGESTED CABLE SYSTEM TRAVEL AND STOP CUSHION FORCES 31 T
35、ABLE 12 AIRCRAFT CONTROL CABLE USAGE . 42 TABLE 13 CONSTRUCTION, PHYSICAL PROPERTIES OF MIL-DTL-83420 TYPE I, CARBON STEEL AND CORROSION RESISTANT STEEL WIRE . 44 TABLE 14 CONSTRUCTION AND DIMENSIONAL PROPERTIES OF MIL-DTL-83420 TYPE II WIRE ROPE JACKET TOLERANCE . 44 TABLE 15 BREAKING STRENGTH OF M
36、IL-DTL-83420 TYPE I AFTER ENDURANCE TESTING 45 TABLE 16 BREAKING STRENGTH OF MIL-DTL-83420 TYPE II AFTER ENDURANCE TESTING . 45 TABLE 17 MIL-DTL-87218 LOCK-CLAD CLASSES AND PHYSICAL PROPERTIES . 46 TABLE 18 MIL-DTL-87218 LOCK-CLAD PERFORMANCE PROPERTIES 46 TABLE 19 BARE CABLE DEFLECTION PROPERTIES .
37、 47 TABLE 20 FRICTION AND CABLE LIFE DESIGN CRITERIA FOR MECHANICAL CONTROLS . 50 TABLE 21 DEFINITION OF SYMBOLS AND TERMINOLOGY FOR CABLE APPLICATIONS 54 TABLE 22 DRUM GROOVE DIMENSIONS . 61 TABLE 23 BELLCRANK DESIGN GUIDELINES . 85 SAE ARP5770 Page 5 of 98 1. SCOPE This SAE Aerospace Recommended P
38、ractice (ARP) provides guidelines for the configuration and design of mechanical control signal transmission systems and subsystems. It is focused on the recommended practices for designing cable and pulley, pushrod and bellcrank and push-pull flexible cable control systems. These systems are typica
39、lly used in some combination to transmit pilot commands into primary, secondary and utility control system commands (mechanical or electrical) or aircraft surface commands. On mechanically controlled aircraft, most pilot control commands are initiated through cockpit mounted wheels, sticks, levers,
40、pedals or cranks that are coupled by pushrods or links to cable systems. The cable systems are routed throughout the aircraft and terminated in close proximity to the commanded surface or function where cranks and pushrods are again used to control the commanded function. 2. REFERENCES 2.1 Applicabl
41、e 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 conflict between the text o
42、f 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. Requirements from many standards and regulations are listed throughout the body of thi
43、s ARP for the readers convenience. Before these requirements are used for design, the current requirements in the governing revision of the referenced standard should be checked. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-
44、7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AS21150 Bearing, Ball, Rod End, Double Row, Precision, Solid Shank, Self-Aligning, Airframe, Type I, -65 to 300 F AS21151 Bearing, Ball, Rod End, Double Row, Precision, External Thread, Self-Aligning, Airframe, Type II, -65 to
45、300 F AS21152 Bearing, Ball, Rod End, Double Row, Precision, Hollow Shank, Self-Aligning, Airframe, Type III, -65 to 300 F AS94900 Aerospace - Flight Control Systems - Design, Installation and Test of Piloted Military Aircraft, General Specification For 2.1.2 EASA Publications Available from Europea
46、n Aviation Safety Agency, Postfach 10 12 53, D-50452 Koeln, Germany, Tel: +49-221-8999-000, www.easa.eu.int. CS-23 Certification Specifications for Normal, Utility, Aerobatic and Commuter Aeroplanes CS-25 Certification Specifications for Large Aeroplanes CS-27 Certification Specifications for Small
47、Rotorcraft CS-29 Certification Specifications for Large Rotorcraft SAE ARP5770 Page 6 of 98 2.1.3 FAA Publications Available from Federal Aviation Administration, 800 Independence Avenue, SW, Washington, DC 20591, Tel: 866-835-5322, www.faa.gov. AC 23.1309 Advisory Circular - System Safety Analysis
48、and Assessment for Part 23 Airplanes AC 25.1309 Advisory Circular - System Design and Analysis AC27-!B Advisory Circular- Certification of Normal Category Rotorcraft AC29-2C Advisory Circular- Certification of Transport Category Rotorcraft 14 CFR 23 Airworthiness Standards: Normal, Utility, Acrobati
49、c and Commuter Category Airplanes 14 CFR 25 Airworthiness Standards: Transport Category Airplanes 14 CFR 27 Airworthiness Standards: Normal Category Rotorcraft 14 CFR 29 Airworthiness Standards: Transport Category Rotorcraft 2.1.4 Joint Aviation Authorities Committee Documents Available from Global Engineering Documents, 15 Inverness Way, Englewood, CO 80112, Tel: 800-854-7179, . JAR-23 Joint Airworthiness Requirements,
