Introduction to Avionics Systems

Introduction to Avionics Systems

by

R.P.G. Collinson BScEng(Hons)., CEng., FIET., FRAeSFormerly Manager of the Flight Automation Research Laboratory of GEC A vionics,

Rochester, Kent, UK (now part of BAE Systems)

Third Edition

Springer Dordrecht Heidelberg London New York

Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

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DOI 10.1007/978-94-007-0708-5 e-ISBN 978-94-007-0708-5 ISBN 978-94-007-0707-8

Library of Congress Control Number: 2011931528

© Springer Science+Business Media B.V. 2011

R.P.G. CollinsonFormerly of GEC Avionics(now part of BAE Systems)Maidstone, KentUnited Kingdom

Contents

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Importance and Role of Avionics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1.1 Systems Which Interface Directly with the Pilot . . . . . . . . . . 31.1.2 Aircraft State Sensor Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 51.1.3 Navigation Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.1.4 Outside World Sensor Systems . . . . . . . . . . . . . . . . . . . . . . . . . 71.1.5 Task Automation Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.2 The Avionic Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111.2.1 Minimum Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141.2.2 Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 141.2.3 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1.3 Choice of Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2 Displays and Man–Machine Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . 192.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.2 Head Up Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.2.2 Basic Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232.2.3 Holographic HUDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302.2.4 HUD Electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362.2.5 Worked Example on HUD Design and Display Generation . 392.2.6 Civil Aircraft HUDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

2.3 Helmet Mounted Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472.3.2 Helmet Design Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

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2.3.3 Helmet Mounted Sights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502.3.4 Helmet Mounted Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512.3.5 Head Tracking Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562.3.6 HMDs and the Virtual Cockpit . . . . . . . . . . . . . . . . . . . . . . . . . 58

2.4 Computer Aided Optical Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

2.5 Discussion of HUDs versus HMDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 622.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 622.5.2 Military Aircraft HUDs and HMDs . . . . . . . . . . . . . . . . . . . . . 62

2.6 Head Down Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662.6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662.6.2 Civil Cockpit Head Down Displays . . . . . . . . . . . . . . . . . . . . . 672.6.3 Military Head Down Displays . . . . . . . . . . . . . . . . . . . . . . . . . . 692.6.4 Display Symbology Generation . . . . . . . . . . . . . . . . . . . . . . . . 702.6.5 Digitally Generated Moving Colour Map Displays . . . . . . . . 712.6.6 Solid State Standby Display Instruments . . . . . . . . . . . . . . . . . 74

2.7 Data Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772.8 Intelligent Displays Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792.9 Displays Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

2.9.1 Replacing the HUD CRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 802.9.2 HMD/HUD Optical System Technology . . . . . . . . . . . . . . . . . 842.9.3 The Q Sight HMD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 882.9.4 The Q HUD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

2.10 Control and Data Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 922.10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 922.10.2 Tactile Control Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932.10.3 Direct Voice Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942.10.4 Speech Output Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 972.10.5 Display Integration with Audio/Tactile Inputs . . . . . . . . . . . . 972.10.6 Eye Trackers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

3 Aerodynamics and Aircraft Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1013.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1013.2 Basic Aerodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

3.2.1 Lift and Drag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1013.2.2 Angle of Incidence/Angle of Attack . . . . . . . . . . . . . . . . . . . . . 1033.2.3 Lift Coefficient and Drag Coefficient . . . . . . . . . . . . . . . . . . . . 1043.2.4 Illustrative Example on Basic Aerodynamics . . . . . . . . . . . . . 1053.2.5 Pitching Moment and Aerodynamic Centre . . . . . . . . . . . . . . 1073.2.6 Tailplane Contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

3.3 Aircraft Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1103.3.1 Longitudinal Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1103.3.2 Aerodynamically Unstable Aircraft . . . . . . . . . . . . . . . . . . . . . 1123.3.3 Body Lift Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

3.4 Aircraft Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

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3.4.1 Aircraft Axes – Velocity and Acceleration Components . . . . 1153.4.2 Euler Angles – Definition of Angles of Pitch, Bank

and Yaw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1183.4.3 Equations of Motion for Small Disturbances . . . . . . . . . . . . . 1193.4.4 Aerodynamic Force and Moment Derivatives . . . . . . . . . . . . 1223.4.5 Equations of Longitudinal and Lateral Motion . . . . . . . . . . . 131

3.5 Longitudinal Control and Response . . . . . . . . . . . . . . . . . . . . . . . . . . . 1343.5.1 Longitudinal Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1343.5.2 Stick Force/g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1353.5.3 Pitch Rate Response to Tailplane/Elevator Angle . . . . . . . . . 1363.5.4 Pitch Response Assuming Constant Forward Speed . . . . . . . 1383.5.5 Worked Example on q/η Transfer Function and Pitch

Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1453.6 Lateral Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

3.6.1 Aileron Control and Bank to Turn . . . . . . . . . . . . . . . . . . . . . . 1483.6.2 Rudder Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1503.6.3 Short Period Yawing Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . 1523.6.4 Combined Roll-Yaw-Sideslip Motion . . . . . . . . . . . . . . . . . . . 153

3.7 Powered Flying Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1543.7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1543.7.2 PCU Transfer Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

3.8 Stability Augmentation Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1573.8.1 Limited Authority Stability Augmentation Systems . . . . . . . 1573.8.2 Full Authority Stability Augmentation Systems . . . . . . . . . . 162

3.9 Helicopter Flight Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1633.9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1633.9.2 Control of the Helicopter in Flight . . . . . . . . . . . . . . . . . . . . . . 1683.9.3 Stability Augmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

4 Fly-by-Wire Flight Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1794.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1794.2 FBW Flight Control Features and Advantages . . . . . . . . . . . . . . . . . . . 180

4.2.1 FBW System Basic Concepts and Features . . . . . . . . . . . . . . . 1804.2.2 Advantages of FBW Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

4.3 Control Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1944.3.1 Pitch Rate Command Control . . . . . . . . . . . . . . . . . . . . . . . . . . 1974.3.2 Lags in the Control Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2074.3.3 Roll Rate Command Control . . . . . . . . . . . . . . . . . . . . . . . . . . 2124.3.4 Handling Qualities and PIOs . . . . . . . . . . . . . . . . . . . . . . . . . . . 2124.3.5 Modern Control Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

4.4 Redundancy and Failure Survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2174.4.1 Safety and Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2174.4.2 Redundant Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2174.4.3 Voting and Consolidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2194.4.4 Quadruplex System Architecture . . . . . . . . . . . . . . . . . . . . . . . 223

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4.4.5 Common Mode Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2244.4.6 Dissimilar Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

4.5 Digital Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2304.5.1 Advantages of Digital Implementation . . . . . . . . . . . . . . . . . . 2304.5.2 Digital Data Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2324.5.3 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2344.5.4 Failure Modes and Effects Analysis . . . . . . . . . . . . . . . . . . . . 242

4.6 Helicopter FBW Flight Control Systems . . . . . . . . . . . . . . . . . . . . . . . 2424.7 Active FBW Inceptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2444.8 Fly-by-Light Flight Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

4.8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2484.8.2 Fly-by-Light Flight Control Systems . . . . . . . . . . . . . . . . . . . . 2504.8.3 Optical Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

5 Inertial Sensors and Attitude Derivation . . . . . . . . . . . . . . . . . . . . . . . . . . 2555.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2555.2 Gyros and Accelerometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

5.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2555.2.2 Micro Electro-Mechanical Systems (MEMS) Technology

Rate Gyros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2575.2.3 Optical Gyroscopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2605.2.4 Accelerometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2765.2.5 Skewed Axes Sensor Configurations . . . . . . . . . . . . . . . . . . . . 282

5.3 Attitude Derivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2835.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2835.3.2 Strap-Down Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2845.3.3 Coning Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2935.3.4 Attitude with Respect to Local North, East, Down Axes . . . . 2945.3.5 Vehicle Rate Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2965.3.6 Introduction to Complementary Filtering . . . . . . . . . . . . . . . . 299

6 Navigation Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3036.1 Introduction and Basic Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303

6.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3036.1.2 Basic Navigation Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 3096.1.3 Basic DR Navigation Systems . . . . . . . . . . . . . . . . . . . . . . . . . 310

6.2 Inertial Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3136.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3136.2.2 Basic Principles and Schuler Tuning . . . . . . . . . . . . . . . . . . . . 3146.2.3 Platform Axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3246.2.4 Initial Alignment and Gyro Compassing . . . . . . . . . . . . . . . . . 3276.2.5 Effect of Azimuth Gyro Drift . . . . . . . . . . . . . . . . . . . . . . . . . . 3306.2.6 Vertical Navigation Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . 3306.2.7 Choice of Navigation Co-ordinates . . . . . . . . . . . . . . . . . . . . . 3346.2.8 Strap-down IN System Computing . . . . . . . . . . . . . . . . . . . . . . 335

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6.3 Aided IN Systems and Kalman Filters . . . . . . . . . . . . . . . . . . . . . . . . . 3376.4 Attitude Heading Reference Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 345

6.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3456.4.2 Azimuth Monitoring Using a Magnetic Heading Reference . 350

6.5 GPS – Global Positioning System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3556.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3556.5.2 GPS System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3576.5.3 Basic Principles of GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3586.5.4 Solution of Navigation Equations . . . . . . . . . . . . . . . . . . . . . . . 3636.5.5 Integration of GPS and INS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3656.5.6 Differential GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3656.5.7 Future Augmented Satellite Navigation Systems . . . . . . . . . . 370

6.6 Terrain Reference Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3726.6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3726.6.2 Terrain Contour Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3736.6.3 Terrain Characteristic Matching . . . . . . . . . . . . . . . . . . . . . . . . 3746.6.4 Civil Exploitation of TRN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

7 Air Data and Air Data Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3777.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3777.2 Air Data Information and Its Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377

7.2.1 Air Data Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3777.2.2 The Air Data Quantities and Their Importance . . . . . . . . . . . . 379

7.3 Derivation of Air Data Laws and Relationships . . . . . . . . . . . . . . . . . . 3837.3.1 Altitude–Static Pressure Relationship . . . . . . . . . . . . . . . . . . . 3847.3.2 Variation of Ground Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 3887.3.3 Air Density versus Altitude Relationship . . . . . . . . . . . . . . . . 3897.3.4 Speed of Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3907.3.5 Pressure–Speed Relationships . . . . . . . . . . . . . . . . . . . . . . . . . . 3927.3.6 Mach Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3957.3.7 Calibrated Airspeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3967.3.8 Static Air Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3987.3.9 True Airspeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3997.3.10 Pressure Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399

7.4 Air Data Sensors and Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4017.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4017.4.2 Air Data System Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . 4017.4.3 Air Data Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4097.4.4 Angle of Incidence Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412

8 Autopilots and Flight Management Systems . . . . . . . . . . . . . . . . . . . . . . . 4158.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4158.2 Autopilots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417

8.2.1 Basic Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4178.2.2 Height Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418

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8.2.3 Heading Control Autopilot . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4198.2.4 ILS/MLS Coupled Autopilot Control . . . . . . . . . . . . . . . . . . . . 4288.2.5 Automatic Landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4338.2.6 Satellite Landing Guidance Systems . . . . . . . . . . . . . . . . . . . . 4398.2.7 Speed Control and Auto-Throttle Systems . . . . . . . . . . . . . . . 440

8.3 Flight Management Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4428.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4428.3.2 Radio Navigation Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4458.3.3 Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4468.3.4 Flight Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4488.3.5 Performance Prediction and Flight Path Optimisation . . . . . . 4518.3.6 Control of the Vertical Flight Path Profile . . . . . . . . . . . . . . . . 4548.3.7 Operational Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4558.3.8 4D Flight Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457

9 Avionics Systems Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4599.1 Introduction and Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4599.2 Data Bus Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466

9.2.1 Electrical Data Bus Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 4669.2.2 Optical Data Bus Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4729.2.3 Parallel Data Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480

9.3 Integrated Modular Avionics Architectures . . . . . . . . . . . . . . . . . . . . . 480

9.4 Commercial Off-the-Shelf (COTS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486

10 Unmanned Air Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48910.1 Importance of Unmanned Air Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . 48910.2 UAV Avionics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49010.3 Brief Overview of Some Current UAVs/UCAVs . . . . . . . . . . . . . . . . . 493

Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499

List of Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509

List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523

9.3.1 Civil Integrated Modular Avionic Systems . . . . . . . . . . . . . . . 483

Foreword

Earlier editions of this book have sold widely, and it has become a standard onavionics used by many universities and colleges, and also by engineering and de-velopment establishments and avionic companies. Although the basic principles ofavionic systems as described are basically unchanged, the period since 2003 whenthe second edition was published, has seen many improvements in technology, andthis third edition has been revised and updated to accommodate these changes.

The extensive revisions include, on displays, the use of ‘commercial off-the-shelf’ graphics processor chips and drive processors for symbology generation, aswell as the replacement of HUD CRTs, and the application of holographic opticalwaveguide technology to helmet mounted displays and HUDs. On Controls, the op-portunity has been taken to add a section on helicopter flight control, and Chapter4 – Fly-by-Wire Flight Control, now includes a description of current Airbus flyby wire, helicopter fly by wire, and active pilot’s control sticks/inceptors incorpor-ating controlled force feedback, The coverage of inertial navigation has also beenupdated, and the section on flight management has been expanded to cover the latestAIRBUS systems. Chapter 9, on System Integration, now includes an overview ofthe modular avionic architectures in the new generation of civil aircraft, such as theA380, and finally the coverage of Unmanned Air Vehicles has been extended, inview of the increasing role they are now playing in both military and civil applica-tions.

Although technological advances will continue to be made, I am confident thatthis updated third edition will ensure that this definitive work will continue to bewidely used by both avionics practitioners and students for many years to come.I am sure that with this book, Dick Collinson, a life-long enthusiast of avionicsengineering and aircraft systems, has made a lasting contribution to avionicsknowledge and experience.

Derek Jackson BSc, C Engformerly Managing Director, Smiths Aerospace, Cheltenham

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Preface

My aims in writing this book were to explain the basic principles underlying the key,or core, avionic systems in modern civil and military aircraft and their implement-ation using modern technology. Technology is continually advancing and this thirdedition incorporates the advances being made since the second edition was finished8 years ago. The opportunity has been taken to extend the coverage of particularareas, where relevant, and helicopter flight control has been added.

The core systems covered comprise pilot’s display systems and man machineinteraction, fly-by-wire flight control systems, inertial sensor systems, navigationsystems, air data systems, autopilots and flight management systems, and avionicsystem integration. Unmanned Air Vehicles (UAVs) are briefly discussed.

The systems are analysed mathematically (where appropriate) from the phys-ical laws governing their behaviour so that the system design and response can beunderstood and the performance analysed. Worked examples are included to showhow the theory can be applied to a representative system. Physical explanations areset out of the system behaviour and the text is structured so that readers can ‘fastforward’ through the maths and just accept the results, if they so wish.

The systems covered are all ‘flight safety critical’. Their implementation usingmodern digital technology to meet the very high safety and integrity requirementsis explained together with the overall integration of these systems.

A particular aim, based on my experience over many years, is to meet the needs ofgraduates (or equivalent) entering the avionics industry who have been educated ina wide variety of disciplines, for example, electronic engineering, computer science,mathematics, physics, mechanical and aeronautical engineering. The book also aimsto meet the needs of engineers at all levels working in particular areas of avionicswho require an appreciation and understanding of other areas and disciplines.

A further objective is to show the very wide range of disciplines which areinvolved in avionic systems, as this makes the subject an interesting and challengingfield. Apart from the interest inherent in aircraft, the range of disciplines and tech-nologies which are exploited covers aerodynamics and aircraft control, satellite nav-igation, optical gyroscopes, man-machine interaction, speech recognition, advanced

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xiv Preface

display systems, holographic optics, intelligent knowledge based systems, closed-loop control systems, high integrity failure survival systems, high integrity software,integrated circuit design and data bus systems.

Personally, I have found avionics to be a very interesting and challenging area towork in and I hope this book will help the reader to share this interest.

Dick CollinsonSeptember 2010

Note: The illustration shows the visual impact of the avionic systems in a modern aircraft.

Acknowledgements

I would like to thank the management of BAE Systems Avionics Group, Rochesterfor their assistance in writing this book and their permission to use a number of theillustrations showing BAE Systems equipment and concepts.

I would also like to express my appreciation to former senior Managers withinthe company who have given their support and encouragement over the years inproducing the first and second editions of this book, and who have now retired. Inparticular, Sue Wood, Brian Tucker, Robin Sleight and Ron Howard.

My thanks and appreciation to my former colleagues in the Company, Chris Bart-lett, Ted Lewis and Paul Wisely for their help and advice on displays technology andJohn Corney for his help and advice on all aspects of flight control, particularly heli-copters. The ‘teach-ins’ over a pint of real ale at the Tiger Moth pub have been apleasant part of writing this book. Paul refers to them as ‘literary lunches’.

I would like to express my appreciation and thanks to Derek Jackson, formerManaging Director of Smiths Aerospace, Cheltenham for his helpful comments andfor writing the Foreword to this third edition.

I would also like to thank my former colleagues Gordon Belcher, Andrew Gib-son, Derek Hamlin, Robin Heaps, and Dave Jibb for their help in obtaining inform-ation, checking the draft chapters and providing helpful and constructive commentsin the earlier editions of this book; most of the theoretical coverage remains un-changed.

I would also like to thank Professor David Allerton, of Cranfield University andProfessor John Roulston, Technical Director, BAE Systems, Avionics Group, fortheir help and support in producing the first and second editions.

The truly excellent work carried out by Bob Ellwood in producing this book isgratefully acknowledged. Producing the typed and formatted text including all theequations to the ‘camera ready copy’ stage was no mean feat.

I would also like to thank Andy Poad for his excellent work in producing mostof the computer-generated illustrations from hand drawn diagrams. My thanks alsoto “Pat” Paternoster for the design and creation of the illustration in the Preface.

Grateful acknowledgement is made to the following companies and organisationsfor permission to use their illustrations and material:

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AgustaWestland Lockheed MartinAirbus Royal Aeronautical Society LibraryBAE Systems Schlumberger IndustriesBEI Systron Donner Inertial Division Smiths IndustriesHoneywell The Boeing Company

Finally, I would like to thank my wife and family for their whole-hearted supportand encouragement in writing this book.