The Principles of Flight for Pilots PDF

‫ﺑﺴﻢ ﺍﷲ ﺍﻟﺮﺣﻤﻦ ﺍﻟﺮﺣﻴﻢ‬ www.asec.ir U U www.ASEC.ir www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come www.ASEC.ir P1: FCG/SPH P2: FCG/...

‫ﺑﺴﻢ ﺍﷲ ﺍﻟﺮﺣﻤﻦ ﺍﻟﺮﺣﻴﻢ‬ www.asec.ir U U www.ASEC.ir www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come The Principles of Flight for Pilots www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come Aerospace Series List Cooperative Path Planning of Unmanned Aerial Tsourdos et al November 2010 Vehicles Principles of Flight for Pilots Swatton October 2010 Air Travel and Health: A Systems Perspective Seabridge et al September 2010 Design and Analysis of Composite Structures: Kassapoglou September 2010 With Applications to Aerospace Structures Unmanned Aircraft Systems: UAVS Design, Austin April 2010 Development and Deployment Introduction to Antenna Placement & Macnamara April 2010 Installations Principles of Flight Simulation Allerton October 2009 Aircraft Fuel Systems Langton et al May 2009 The Global Airline Industry Belobaba April 2009 Computational Modelling and Simulation of Diston April 2009 Aircraft and the Environment: Volume 1 – Platform Kinematics and Synthetic Environment Handbook of Space Technology Ley, Wittmann Hallmann April 2009 Aircraft Performance Theory and Practice for Swatton August 2008 Pilots Surrogate Modelling in Engineering Design: A Forrester, Sobester, Keane August 2008 Practical Guide Aircraft Systems, 3rd Edition Moir & Seabridge March 2008 Introduction to Aircraft Aeroelasticity And Wright & Cooper December 2007 Loads Stability and Control of Aircraft Systems Langton September 2006 Military Avionics Systems Moir & Seabridge February 2006 Design and Development of Aircraft Systems Moir & Seabridge June 2004 Aircraft Loading and Structural Layout Howe May 2004 Aircraft Display Systems Jukes December 2003 Civil Avionics Systems Moir & Seabridge December 2002 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come The Principles of Flight for Pilots P. J. Swatton A John Wiley and Sons, Ltd., Publication www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come This edition first published 2011
C 2011 John Wiley & Sons Ltd Registered offic John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com. The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Swatton, P. J. (Peter J.) The principles of flight for pilots / P. J. Swatton. p. cm. Includes index. ISBN 978-0-470-71073-9 (pbk.) 1. Airplanes–Piloting. 2. Aerodynamics. 3. Flight. I. Title. TL710.S774 2010 629.132–dc22 2010014529 A catalogue record for this book is available from the British Library. Print ISBN: 9780470710739 ePDF ISBN: 9780470710937 oBook ISBN: 9780470710944 Set in 9/11 Times by Aptara Inc., New Delhi, India. www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come Contents Series Preface xxi Preface xxiii Acknowledgements xxv List of Abbreviations xxvii Weight and Mass xxxi PART 1 THE PRELIMINARIES 1 1 Basic Principles 3 1.1 The Atmosphere 3 1.2 The Composition of Air 3 1.2.1 The Measurement of Temperature 3 1.2.2 Air Density 4 1.3 The International Standard Atmosphere 4 1.3.1 ISA Deviation 5 1.3.2 JSA Deviation 5 1.3.3 Height and Altitude 6 1.3.4 Pressure Altitude 7 1.3.5 Density Altitude 7 1.4 The Physical Properties of Air 7 1.4.1 Fluid Pressure 7 1.4.2 Static Pressure 7 1.4.3 Dynamic Pressure 7 1.5 Newton’s Laws of Motion 8 1.5.1 Definitions 8 1.5.2 First Law 8 1.5.3 Second Law 8 1.5.4 Third Law 9 1.6 Constant-Acceleration Formulae 9 1.7 The Equation of Impulse 9 1.8 The Basic Gas Laws 10 1.8.1 Boyles Law 10 1.8.2 Charles’ Law 10 1.8.3 Pressure Law 10 1.8.4 The Ideal Gas Equation 10 1.9 The Conservation Laws 11 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come vi CONTENTS 1.10 Bernoulli’s Theorem 11 1.10.1 Viscosity 11 1.11 The Equation of Continuity 12 1.12 Reynolds Number 12 1.12.1 Critical Reynolds Number (Recrit ) 13 1.13 Units of Measurement 13 Self-Assessment Exercise 1 15 2 Basic Aerodynamic Definitions 19 2.1 Aerofoil Profile 19 2.2 Aerofoil Attitude 20 2.3 Wing Shape 21 2.4 Wing Loading 23 2.5 Weight and Mass 24 2.5.1 The Newton 24 2.6 Airspeeds 24 2.6.1 Airspeed Indicator Reading (ASIR) 24 2.6.2 Indicated Airspeed (IAS) 25 2.6.3 Calibrated Airspeed (CAS) 25 2.6.4 Rectified Airspeed (RAS) 25 2.6.5 Equivalent Airspeed (EAS) 25 2.6.6 True Airspeed (TAS) 25 2.6.7 Mach Number 26 2.7 Speed Summary 26 2.8 The Effect of Altitude on Airspeeds 27 2.8.1 a. Below the Tropopause 27 2.8.2 b. Above the Tropopause 27 Self-Assessment Exercise 2 29 PART 2 BASIC AERODYNAMICS 33 3 Basic Control 35 3.1 Aeroplane Axes and Planes of Rotation 35 3.1.1 The Longitudinal or Roll Axis 35 3.1.2 The Lateral or Pitch Axis 35 3.1.3 The Normal or Yaw Axis 35 3.2 The Flight Controls 35 3.3 The Elevators 37 3.4 Pitch Control 37 3.4.1 Control Surface Area 38 3.4.1.1 Control Surface Angular Deflection 38 3.4.2 The Moment Arm 38 3.4.3 Angle of Attack 38 3.5 Alternative Pitch Controls 39 3.5.1 Variable Incidence Tailplane 39 3.5.2 The Stabilator 40 3.5.3 The Elevons 40 3.6 The Rudder 40 3.7 Yaw Control 41 3.7.1 Control-Surface Area 41 3.7.1.1 Control-Surface Deflection 41 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS vii 3.7.2 The Moment Arm 41 3.7.2.1 Engine-Induced Yaw 41 3.8 Asymmetric Engine Yawing Moment 42 3.8.1 Critical Power Unit 42 3.9 Asymmetric Rolling Moment 43 3.10 Minimum Control Speeds 44 3.10.0.1 For Take-off 44 3.10.0.2 For Landing 44 3.10.1 Vmc 44 3.10.2 Vmcg 44 3.10.2.1 The Effect of the Variables on Vmcg and Vmc 45 3.10.3 Vmcl 45 3.10.4 Vmcl(1out) 45 3.10.5 Vmcl-2 46 3.10.5.1 The Effect of the Variables on Vmcl 46 3.11 The Ailerons 46 3.12 Roll Control 46 3.12.1 The Flaperon 47 3.13 Wing Twist 47 3.14 Geometric Twist 47 3.15 Aerodynamic Twist 47 3.15.1 Twisterons 48 3.16 High-Speed Twist 49 3.16.1 Low-Speed Ailerons 49 3.16.2 High-Speed Ailerons 49 3.16.3 Roll Spoilers 50 Self-Assessment Exercise 3 51 4 Lift Generation 55 4.1 Turbulent Flow 55 4.2 Streamline Flow 55 4.3 The Boundary Layer 57 4.4 The Laminar Boundary Layer 58 4.4.1 The Transition Point 58 4.5 The Turbulent Boundary Layer 58 4.5.1 Leading-Edge Separation 59 4.6 Boundary-Layer Control 59 4.6.1 Blowing 59 4.6.2 Suction 60 4.6.3 Vortex Generators 60 4.7 Two-Dimensional Flow 61 4.8 The Stagnation Point 61 4.8.1 Aerofoil Upper-Surface Airflow 61 4.8.2 Aerofoil Lower-Surface Airflow 61 4.9 Lift Production 62 4.9.1 Symmetrical Aerofoils 62 4.9.2 Cambered Aerofoils 62 4.9.2.1 a. Negative Angles of Attack 64 4.9.2.2 b. Small Positive Angles of Attack 64 4.9.2.3 c. Large Positive Angles of Attack 64 4.10 The Centre of Pressure (CP) 64 4.11 Pitching Moments 65 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come viii CONTENTS 4.12 The Aerodynamic Centre 67 4.13 Three-Dimensional Flow 68 4.14 Wing-Tip Vortices 68 4.15 Wake Turbulence 70 4.16 Spanwise Lift Distribution 70 4.16.1 The Effect of Wing Planform 70 Self-Assessment Exercise 4 75 PART 3 LEVEL-FLIGHT AERODYNAMICS 79 5 Lift Analysis 81 5.1 The Four Forces 81 5.2 Mass 81 5.3 Lift Analysis 82 5.4 The Factors Affecting Cl 84 5.5 The Effect of Angle of Attack 84 5.6 The Effect of the Wing Shape 85 5.6.1 The Effect of Leading-Edge Radius 86 5.6.2 The Effect of Camber 86 5.6.3 The Effect of Aspect Ratio 87 5.6.4 The Wing Planform 88 5.6.4.1 The Effect of Sweepback 88 5.7 The Effect of Airframe-Surface Condition 89 5.8 The Effect of Reynolds Number 91 5.9 The Relationship between Speeds, Angles of Attack and Cl 92 5.10 Aerofoil Profiles 93 5.10.1 High-Lift Aerofoils 93 5.10.2 General-Purpose Aerofoils 94 5.10.3 High-Speed Aerofoils 94 Self-Assessment Exercise 5 95 6 Lift Augmentation 99 6.1 Wing Loading 99 6.2 Clmax Augmentation 99 6.3 Slats 100 6.3.1 Automatic Slats 101 6.3.2 Manual Slats 103 6.4 Slots 103 6.5 Leading-Edge Flaps 103 6.5.1 The Krueger Flap 105 6.5.2 The Drooped Leading Edge 106 6.6 Trailing-Edge Flaps 106 6.6.1 The Plain Trailing-Edge Flap 107 6.6.2 The Split Trailing-Edge Flap 108 6.6.3 The Slotted Trailing-Edge Flap 108 6.6.4 The Fowler Flap 109 6.6.4.1 The Effect of Trailing-Edge Flaps 110 6.6.5 Leading- and Trailing-Edge Combinations 110 6.6.5.1 The Effect of Sweepback on Flap 112 Self-Assessment Exercise 6 113 7 Drag 119 7.1 Parasite (Profile) Drag 119 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS ix 7.2 Surface-Friction Drag 120 7.2.0.1 Surface Area 120 7.2.0.2 Coefficient of Viscosity 120 7.2.0.3 Rate of Change of Airspeed 120 7.2.1 Flow Transition 120 7.2.1.1 Surface Condition 121 7.2.1.2 Speed and Size 121 7.2.1.3 Adverse Pressure Gradient 121 7.3 Form (Pressure) Drag 121 7.3.1 Interference Drag 122 7.4 Induced Drag 122 7.4.1 The Effect of Speed 123 7.4.2 The Effect of Mass 125 7.4.3 The Effect of Planform 125 7.4.4 The Effect of Sweepback 125 7.4.5 The Effect of Aspect Ratio 126 7.4.6 The Effect of Flap 126 7.4.7 The Effect of the CG Position 126 7.4.8 Effects Summary 127 7.5 Ground Effect 127 7.6 Wing-Tip Design 128 7.7 Wingspan Loading 129 7.8 The Coefficient of Induced Drag (Cdi) 129 7.9 Total Drag 130 7.10 Analysis of the Total-Drag Curve 130 7.11 The Velocity of Minimum Drag (Vimd) 130 7.12 The Velocity of Minimum Power (Vimp) 132 7.13 The Maximum EAS/Drag Ratio (Vi/Dmax) Speed 132 7.14 Speed Stability and Instability 133 7.15 The Effect of the Variables on Total Drag 134 7.15.1 The Effect of Altitude 134 7.15.2 The Effect of Mass 134 7.15.3 The Effect of Flap 134 7.16 The Cl v Cd Polar Diagram 136 7.17 Analysis of the Lift/Drag Ratio 137 7.17.1 The Effect of Flap 138 7.17.2 The Effect of Aspect Ratio 138 7.17.3 The Effect of Mass 139 7.18 Drag Augmentation 139 7.19 Airbrakes 139 7.20 Spoilers 139 7.20.1 Flight Spoilers 139 7.20.2 Ground Spoilers 140 7.20.3 Roll Spoilers 141 7.21 Barn-Door Flaps 142 7.22 Drag Parachutes 142 Self-Assessment Exercise 7 143 8 Stalling 153 8.0.1 The Stall 153 8.1 The Boundary Layer 153 8.2 Boundary-Layer Separation 154 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come x CONTENTS 8.2.1 Trailing-Edge Separation 154 8.2.2 Leading-Edge Separation 155 8.3 The Low-Speed Stalling Angle 156 8.4 Factors Affecting the Low-Speed Stalling Angle 156 8.4.1 Slat/Flap Setting 156 8.4.2 Ice Accretion 157 8.4.3 Effect on Take-off and Landing 158 8.4.3.1 Take-Off 158 8.4.3.2 Landing 158 8.4.3.3 Reduced Stalling Angle 159 8.4.3.4 Abnormal Stalling Characteristics 159 8.4.4 Heavy Rain 159 8.5 The Effect of Wing Design on the Low-Speed Stall 159 8.5.1 Swept Wings 160 8.5.2 Elliptical Wings 161 8.5.3 Rectangular Wings 161 8.5.4 Straight Tapered Wings 161 8.6 Spanwise-Flow Attenuation Devices 161 8.6.1 The Wing Fence 162 8.6.2 The Sawtooth Leading Edge 162 8.6.3 The Notched Leading Edge 162 8.6.4 Vortex Generators 162 8.7 Wing-Tip Stalling 164 8.7.1 The Effect of Flap 164 8.7.2 The Prevention of Wing-Tip Stalling 165 8.7.2.1 a. Washout. 165 8.7.2.2 b. Root Spoiler. 165 8.7.2.3 c. Changing Camber. 165 8.7.2.4 d. Slats and Slots. 165 8.7.2.5 e. Aspect Ratio. 165 8.8 Stalling Characteristics 165 8.8.1 Ideal Stalling Characteristics 165 8.8.2 Swept-Wing Stalling Characteristics 166 8.9 Summary of Factors Affecting the Stalling Angle 166 8.10 Aerodynamic Stall Warning 166 8.11 Mechanical Stall Warning 167 8.11.1 The Flapper Switch 167 8.11.2 The Angle of Attack Sensor 167 8.11.3 Stick Shakers 168 8.11.4 Stick Pushers 168 8.12 Stalling Speed 168 8.13 Factors Affecting Stalling Speed 169 8.14 Centre of Gravity (CG) 169 8.14.1 Forward CG 169 8.14.1.1 Disadvantage 169 8.14.1.2 Advantage 169 8.14.2 Aft CG 169 8.14.2.1 Disadvantage 170 8.14.2.2 Advantage 170 8.15 Mass 170 8.16 Altitude 171 8.17 Configuration 171 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS xi 8.18 Ice Accretion 171 8.19 Wing Planform 172 8.20 Summary of Factor Effects on Stalling Speed 172 8.21 The Speed Boundary 172 8.22 The Effect of a Gust on the Load Factor 173 8.23 Turn Stalling Speed 174 8.24 Stalling-Speed Definitions 174 8.24.1 Vclmax 175 8.24.2 Vms 175 8.24.3 Vms0 175 8.24.4 Vms1 175 8.24.5 Vs 176 8.24.6 Vs0 176 8.24.7 Vs1 176 8.24.8 Vs1g 176 8.24.9 Vsr 176 8.24.10 Vsr0 176 8.24.11 Vsr1 176 8.25 The Deep Stall 177 8.26 The Accelerated Stall 177 8.27 The Power-On Stall 177 8.28 The Shock Stall 178 8.29 Stall Recovery 178 8.29.1 The Low-speed Stall 178 8.29.2 The Deep Stall 178 8.29.3 The Accelerated Stall 178 8.29.4 The Power-On Stall 179 8.29.5 The Shock Stall 179 8.30 The Spin 179 Self-Assessment Exercise 8 181 9 Thrust and Power in Level Flight 189 9.1 Thrust 189 9.2 Analysis of the Thrust Curves 189 9.2.1 Thrust Available 189 9.2.2 Thrust Required 190 9.2.2.1 Maximum Speed (EAS) 190 9.3 The Effect of the Variables on Thrust 191 9.3.1 Altitude 191 9.3.2 Mass 193 9.3.3 Asymmetric Flight 193 9.3.4 Centre of Gravity 195 9.4 Power 196 9.5 Analysis of the Power Curves 196 9.5.1 Maximum TAS 197 9.5.2 Vmp and Vmd 197 9.6 The Effect of the Variables on Power 198 9.6.1 Altitude 198 9.6.2 Mass 200 9.7 Summary 201 Self-Assessment Exercise 9 203 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come xii CONTENTS 10 Advanced Control 207 10.1 Wing Torsion and Flexing 207 10.2 Wing Flutter 207 10.3 Torsional Flexural Flutter 207 10.4 Aileron Flutter 210 10.4.1 Torsional Aileron Flutter 210 10.4.2 Flexural Aileron Flutter 211 10.4.2.1 The Mass Balance 212 10.5 Divergence 213 10.6 Control Secondary Effects 213 10.7 Adverse Yaw 213 10.8 Counteraction Devices 214 10.8.1 Rudder/Aileron Coupling 214 10.8.2 Slot/Aileron Coupling 214 10.8.3 Spoiler/Aileron Coupling 214 10.8.4 Differential Aileron Deflection 214 10.8.5 Frise Ailerons 214 10.9 Control-Surface Operation 215 10.10 Aerodynamic Balance Methods 216 10.10.1 The Hinge Balance 216 10.10.2 The Horn Balance 216 10.10.3 The Internal Balance 217 10.10.4 The Balance Tab 217 10.10.5 The Antibalance Tab 218 10.10.6 The Spring Tab 218 10.10.7 The Servo Tab 220 10.11 Primary Control-Surface Trimming 221 10.11.1 Variable Trim Tabs 222 10.11.2 Fixed Trim Tabs 222 10.11.3 Stabilizer Trim Setting 222 10.12 Powered Controls 223 10.13 Power-Assisted Controls 223 10.14 Fully Powered Controls 223 10.14.1 Artificial Feel 224 10.14.1.1 The Simple System 224 10.14.1.2 The Servo-Assisted Hydraulic System 224 10.15 Fly-by-Wire 225 Self-Assessment Exercise 10 227 PART 4 STABILITY 231 11 Static Stability 233 11.1 Static Stability 233 11.2 The Effect of the Variables on Static Stability 235 11.3 Directional Static Stability 235 11.4 Yaw and Sideslip 235 11.5 The Directional Restoring Moment 235 11.5.1 Fin and Rudder Design 237 11.5.2 The Dorsal Fin 237 11.5.3 The Ventral Fin 237 11.5.4 The Moment Arm 237 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS xiii 11.6 Aeroplane Design Features Affecting Directional Static Stability 238 11.6.1 Fuselage 238 11.6.2 Wing 238 11.6.2.1 Dihedral 239 11.6.3 Sweepback 239 11.7 Propeller Slipstream 240 11.8 Neutral Directional Static Stability 240 11.9 Lateral Static Stability 240 11.10 Aeroplane Design Features Affecting Lateral Static Stability 242 11.10.1 Increased Lateral Static Stability 242 11.10.2 Decreased Lateral Static Stability 242 11.11 Sideslip Angle and Rolling Moment Coefficient 243 11.12 Analysis of Design Feature Effects 244 11.13 Wing Contribution 244 11.13.1 Dihedral 244 11.13.2 Anhedral 245 11.13.3 Sweepback 245 11.14 Wing/Fuselage Interference 246 11.14.1 Shielding Effect 246 11.14.2 Wing Location 246 11.15 Fuselage/Fin 246 11.15.1 Fin Size 246 11.15.2 Ventral Fin 246 11.16 Handling Considerations 247 11.16.1 Propeller Slipstream 247 11.16.2 Crosswind Landings 247 11.16.3 Flaps 247 11.17 Longitudinal Static Stability 248 11.18 The Centre of Pressure (CP) 249 11.19 The Neutral Point (NP) 250 11.19.1 Types of Static Neutral Point 250 11.19.1.1 The Stick-Free Static Neutral Point 250 11.19.1.2 The Stick-Fixed Static Neutral Point 250 11.19.2 The Effect of the CG at the NP 250 11.20 The Aerodynamic Centre (AC) 251 11.21 The Centre of Gravity (CG) 251 11.21.1 The CG Envelope 251 11.21.1.1 CG Envelope Limitations 251 11.21.1.2 CG Movement 252 11.21.2 The Effect of CG at the Limits 252 11.21.2.1 CG at the Forward Limit 252 11.21.2.2 CG at the Aft Limit 252 11.22 The Static Margin (SM) 253 11.23 The Trim Point (TP) 253 11.24 Longitudinal Dihedral 253 11.25 Aeroplane-Design Variations 255 11.26 The Effect of the Variables on Longitudinal Static Stability 255 11.26.1 Elevator Deflection 255 11.26.2 Trim 256 11.26.3 The Fuselage 257 11.26.4 Angle of Attack 257 11.26.5 Configuration 257 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come xiv CONTENTS 11.26.5.1 Trailing-Edge Flaps 257 11.26.5.2 Undercarriage 257 11.27 Stick-Fixed Longitudinal Static Stability 257 11.27.1 Stick-Position Stability 258 11.28 Stick-Free Longitudinal Static Stability 258 11.28.1 Stick Force 259 11.29 Certification Standard Stick-Force Requirements 260 11.29.1 a. Class ‘A’ Aeroplanes CS 25.173(c) 260 11.29.2 b. Class ‘B’ Aeroplanes CS 23.173(c) 260 11.30 The Effect of CG Position on Stick Force 260 11.31 Longitudinal Static Manoeuvre Stability 261 11.31.1 The Manoeuvre Point 261 11.32 Factors Affecting Stick Force 262 11.33 Summary 262 11.34 The Effect of Atmospheric Conditions 264 11.34.1 Ice Accretion 264 11.34.2 Heavy Rain 264 11.34.3 Altitude 264 11.35 The Factors Affecting Static Stability 264 Self-Assessment Exercise 11 267 12 Dynamic Stability 277 12.1 Longitudinal Dynamic Stability 279 12.1.1 The Phugoid 279 12.1.2 Short-Period Oscillation 280 12.1.3 Factors Affecting Longitudinal Dynamic Stability 280 12.2 Lateral Dynamic Stability 280 12.2.1 Sideslip 281 12.2.2 Rolling 281 12.2.3 Spiral 281 12.2.4 Dutch Roll 281 12.3 Spiral Instability 281 12.4 Dutch Roll 282 12.5 Asymmetric Thrust 282 12.6 Aerodynamic Damping 283 12.7 Summary 283 12.8 The Factors Affecting Dynamic Stability 283 12.8.1 a. General 283 12.8.2 b. Longitudinal 284 12.8.3 c. Lateral 284 Self-Assessment Exercise 12 285 PART 5 MANOEUVRE AERODYNAMICS 289 13 Level-Flight Manoeuvres 291 13.1 The Manoeuvre Envelope 291 13.1.1 The Flight Load Factor 291 13.2 Manoeuvre-Envelope Limitations 291 13.2.1 The Stalling Speed 291 13.2.2 The ‘g’ Limitation 292 13.2.3 The Manoeuvre-Envelope Limiting Parameters 294 13.2.4 The Manoeuvre-Envelope Maximum-Speed Limitation 294 13.3 Stalling and Design Speed Definitions 294 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS xv 13.4 Limiting Speeds 296 13.5 The Load Factor 296 13.6 The Gust Load Factor 297 13.7 Buffet 299 13.7.1 Low-Speed Buffet 299 13.7.2 High-Speed Buffet 300 13.8 The Buffet Onset Boundary Chart 300 13.9 Turns 302 13.9.1 The Load Factor in a Turn 303 13.9.2 The Turn Radius 303 13.9.3 Rate of Turn 305 13.10 Turn and Slip Indications 306 Self-Assessment Exercise 13 307 14 Climb and Descent Aerodynamics 315 14.1 Climbing Flight 315 14.2 The Forces in a Climb 315 14.3 The Effect of the Variables on the Climb 316 14.3.1 Altitude 316 14.3.2 Mass 316 14.3.3 Flap Setting 316 14.3.4 Wind Component 317 14.4 Climb Gradient 317 14.5 Climb-Gradient Calculations 318 14.5.1 Method 1 318 14.5.2 Method 2 320 14.6 Rate of Climb 321 14.7 Rate-of-Climb Calculations 321 14.8 Vx and Vy 323 14.9 Vx 323 14.10 Vy 325 14.11 Aircraft Ceiling 326 14.12 Vy at the Absolute Ceiling 327 14.12.1 Piston/Propeller Aeroplanes 328 14.12.2 Jet Aeroplanes 328 14.13 The Effect of the Variables on Vx and Vy 329 14.13.1 Mass 329 14.13.2 Flap 329 14.13.3 Altitude 329 14.13.4 Temperature 329 14.13.5 Wind Component 329 14.14 The Effect of Climbing-Speed Variations 331 14.15 Factors Affecting the Climb 332 14.16 The Glide Descent 332 14.16.1 The Glide Variables 333 14.17 Gliding for Maximum Range 334 14.18 The Effect of the Variables on a Glide Descent 335 14.18.1 Speed 335 14.18.2 Wind Component 336 14.18.3 Mass 337 14.18.4 Angle of Attack 338 14.18.5 Flap 338 14.19 Gliding for Maximum Endurance 338 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come xvi CONTENTS 14.20 Climbing and Descending Turns 339 Self-Assessed Exercise 14 341 PART 6 OTHER AERODYNAMIC CONSIDERATIONS 349 15 High-Speed Flight 351 15.0.1 General Introduction 351 15.1 High-Speed Definitions 352 15.2 High-Speed Calculations 352 15.3 The Shockwave 353 15.3.1 Compressibility 353 15.3.2 Shockwave Formation 353 15.4 Air-Pressure-Wave Patterns 354 15.4.1 Subsonic 357 15.4.2 Sonic 357 15.4.3 Supersonic 357 15.5 The Shockwave Deflection Angle 357 15.6 The High-Speed CP 358 15.7 Critical Mach Number (Mcrit) 358 15.8 The Effect of a Shockwave 359 15.8.1 Wave Drag 359 15.8.2 Drag Divergence Mach Number 360 15.9 The Flying Controls 360 15.10 The Effect of the Aerofoil Profile 361 15.10.1 Thickness/Chord Ratio 362 15.10.2 Wing Camber 362 15.11 Swept Wings 362 15.12 The Effect of Sweepback 362 15.12.1 The Advantages of Sweepback 362 15.12.1.1 Increased Mcrit 363 15.12.1.2 Aerodynamic Effects 363 15.12.2 The Disadvantages of Sweepback 363 15.13 Remedial Design Features 364 15.13.1 Low-Speed Ailerons 365 15.13.2 High-Speed Ailerons 365 15.14 Area Rule 365 15.15 High-Speed-Flight Characteristics 367 15.15.1 High-Speed Buffet 367 15.15.2 Tuck Under 367 15.15.3 The Shock Stall 367 15.15.4 The Buffet Boundary 368 15.15.5 Coffin Corner 368 15.16 Speed Instability 368 15.16.1 The Mach Trimmer 369 15.16.2 Lateral Instability 369 15.17 The Supercritical Wing 369 15.18 Supersonic Airflow 370 15.18.1 The Convex Corner Mach Wave (Expansion Wave) 370 15.18.2 The Concave-Corner Shockwave 372 Self-Assessment Exercise 15 373 16 Propellers 387 16.1 Propeller Definitions 387 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS xvii 16.2 Basic Principles 389 16.3 Factors Affecting Propeller Efficiency 391 16.4 Airspeed 391 16.4.1 Fixed-Pitch Propellers 391 16.4.2 Variable-Pitch Propellers 393 16.5 Power Absorption 393 16.5.1 Propeller-Blade Shape 393 16.5.1.1 Blade Length 393 16.5.1.2 Blade Chord 394 16.5.2 Propeller-Blade Number 394 16.5.3 Solidity 394 16.6 The Effects of a Propeller on Aeroplane Performance 395 16.6.1 Torque 395 16.6.2 Slipstream Effect 396 16.6.3 Asymmetric Blade 396 16.6.4 Gyroscopic Effect 397 16.7 Propeller Forces and Moments 398 16.7.1 Centrifugal Force (CF) 398 16.7.2 Centrifugal Twisting Moment (CTM) 398 16.7.3 Aerodynamic Twisting Moment (ATM) 398 16.8 Propeller-Blade Positions 400 16.9 The Constant-Speed Unit (CSU) 400 16.9.1 Propeller Windmilling 401 16.9.2 Propeller Feathering 401 16.9.3 Reverse Pitch 403 16.10 The Effect of a Constant Speed Propeller On a Glide Descent 403 16.11 Engine Failure 403 Self-Assessment Exercise 16 405 17 Operational Considerations 411 17.1 Runway-Surface Contamination 411 17.1.1 Surface Contaminants 411 17.1.1.1 Standing Water 411 17.1.1.2 Slush 411 17.1.1.3 Wet Snow 411 17.1.1.4 Dry Snow 412 17.1.1.5 Very Dry Snow 412 17.1.1.6 Compacted Snow 412 17.1.1.7 Ice 412 17.1.1.8 Specially Prepared Winter Runway 412 17.1.1.9 Mixtures 412 17.1.1.10 Contaminant Drag 413 17.1.1.11 Water-Equivalent Depth 413 17.2 The Effect of Runway Contamination 413 17.2.1 Take-off 413 17.3 Aeroplane Contamination 415 17.3.1 The Effect of Heavy Rain 415 17.3.2 The Effect of Propeller Icing 415 17.3.3 The Effect of Airframe Icing 416 17.3.4 The Effect of Airframe-Surface Damage 416 17.3.5 The Effect of Turbulence 416 17.4 Windshear 417 17.4.1 The Effect of Windshear 417 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come xviii CONTENTS 17.4.1.1 Energy Loss 417 17.4.1.2 Energy Gain 417 17.4.2 Downdraught 418 17.4.2.1 Take-off 418 17.4.2.2 Landing 418 17.4.3 Countering Windshear 419 Self-Assessment Exercise 17 421 PART 7 CONCLUSION 425 18 Summary 427 18.1 Aerofoil-Profile Definitions 427 18.2 Aerofoil-Attitude Definitions 427 18.3 Wing-Shape Definitions 428 18.4 High-Speed Definitions 428 18.5 Propeller Definitions 429 18.6 V Speeds 430 18.7 PoF Formulae 432 18.7.1 Drag 433 18.7.2 Wing Loading/Load Factor 433 18.7.3 Stalling Speed Calculations 434 18.7.3.1 Mass Change 434 18.7.3.2 Load Factor 434 18.7.3.3 Turn 434 18.7.4 Design Manoeuvre Speed (Va) 434 18.7.5 Turn Details 434 18.7.5.1 Radius of Turn 434 18.7.5.2 Rate of Turn 434 18.7.6 Climb Calculations 434 18.7.7 Descent Calculations 434 18.7.7.1 Maximum Glide Range 435 18.7.8 Mach Angle (␮) Calculation 435 18.8 Key Facts 435 18.9 Stalling 435 18.9.1 The Maximum Coefficient of Lift (Clmax) 435 18.9.2 The Critical Angle 435 18.9.3 The Stalling Speed 436 18.10 Stability 436 18.10.1 Static Stability 436 18.10.2 Dynamic Stability 436 18.10.3 The Stick Force 438 18.10.4 The Gust Load Factor 439 18.11 Propellers 439 18.11.1 Propeller Efficiency 439 18.11.2 Fixed Pitch Angle of Attack 439 18.11.3 Propeller Gyroscopic Effect 440 18.12 The Effect of the Variables on Performance 440 18.12.1 Airframe Surface 440 18.12.2 Airframe Surface 440 18.12.3 Altitude 441 18.12.4 Aspect Ratio 441 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come CONTENTS xix 18.12.5 Camber 441 18.12.6 CG Position 442 18.12.7 Flap 442 18.12.8 Sweepback 443 18.12.9 Dihedral 443 18.12.10 Mass 443 Self-Assessment Exercise 18 445 19 Solutions (with page references) 447 Self-Assessment Exercise 1 447 Self-Assessment Exercise 2 447 Self-Assessment Exercise 3 448 Self-Assessment Exercise 4 448 Self-Assessment Exercise 5 448 Self-Assessment Exercise 6 449 Self-Assessment Exercise 7 450 Self-Assessment Exercise 8 451 Self-Assessment Exercise 9 452 Self-Assessment Exercise 10 453 Self-Assessment Exercise 11 453 Self-Assessment Exercise 12 454 Self-Assessment Exercise 13 454 Self-Assessment Exercise 14 456 14.0.1 Vx & Vy Mathematical Proof 457 Self-Assessment Exercise 15 458 Self-Assessment Exercise 16 459 Self-Assessment Exercise 17 459 Self-Assessment Exercise 18 Turn Calculations 460 Index 461 www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 17:17 Printer Name: Yet to Come www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come Series Preface The field of aerospace is wide ranging and covers a variety of products, disciplines and domains, not merely in engineering but in many supporting activities. These combine to enable the aerospace industry to produce exciting and technologically challenging products. A wealth of knowledge is contained by practitioners and professionals in the industry in the aerospace fields that is of benefit to other practitioners in the industry, and to those entering the industry from University or other fields. The Aerospace Series aims to be a practical and topical series of books aimed at engineering professionals, operators and users and allied professions such as commercial and legal executives in the aerospace industry. The range of topics spans design and development, manufacture, operation and support of the aircraft as well as infrastructure operations, and developments in research and technology. The intention is to provide a source of relevant information that will be of interest and benefit to all those people working in aerospace. The other books in the Aerospace Series concentrate very much on the technical aspects of Airframe, Structure and Systems - providing technical descriptions that are of use to engineers and designers. In most of these books the Human Machine interface is described, especially in Aircraft Display Systems. Aircraft Performance, Theory and Practice for Pilots by P. J. Swatton extended the Series from the Design phase of the life-cycle into the operate phase by introducing aspects of the aircraft that are essential to the pilot. In this book, Principles of Flight for Pilots, the author takes this a step further by introducing principles of flight in a comprehensive and easy to use compendium of knowledge complemented by self-assessment exercises. The book is packed with information from basic aerodynamics and stability through aerodynamic principles for level flight, manoeuvre and high speed flight. Even though this book is aimed squarely at pilots wishing to study for the EASA ATPL and CPL examinations, it should also be considered as essential reading for students wishing to enter the field of aero engineering and for practitioners in systems engineering, design, aerodynamics and testing. Allan Seabridge www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come Preface Since the Wright brothers’ triumphant production of a flying machine in 1903, followed by Bleriot’s successful navigation of the Channel in 1909, the mysteries of how an aeroplane flies have fascinated almost everyone. Although aerodynamics is a complicated subject it is essential that all aviators have a basic understanding of the principles of flight for the safety of themselves and those on the ground, without the prerequisite of comprehending all of the mathematics involved. This is the prime objective of the syllabus formulated by the JAA and now adopted by EASA. Although the knowledge and manipulation of some formulae is required, the syllabus limits it to those necessary to safely execute the duties of a pilot. The aim of this book is to provide a trustworthy work of reference for pilots. It is collated and presented in such a manner that it will not only help student pilots to pass the examination but will also enable experienced personnel to gain a deeper understanding of the Principles of Flight and related subjects. It is not intended to be a comprehensive study of aerodynamics. An examination in Principles of Flight is set by the Flight Crew Licensing Department of the Civil Aviation Authority (CAA) acting as an agent for EASA. To validate a licence, together with other requirements, a candidate must attain a mark of at least 75% in the examination. Principles of Flight for Pilots The Complete Manual. This manual has been written in a manner for easy learning primarily for trainee pilots wishing to study for the EASA ATPL and CPL licence examinations. It is also a useful reference book for qualified transport aeroplane pilots and has been comprehensively indexed for easy use. The manual is divided into seven parts. Each part contains the necessary number of chapters to explain the appropriate topic in detail. After each chapter is a set of self-assessed questions that have been gleaned from the feedback of previous candidates in the Principles of Flight examination over the past nine years. The calculations and explanations to the correct solutions are those of the author are given in Chapter 19. Part 1 – The Preliminaries. This part of the manual is devoted to an introduction to that area of basic physics applicable to the principles of flight and to the definitions that are used in the subsequent chapters. Part 2 – Basic Aerodynamics. Theoretical aspects of aeroplane control and lift generation are confined to this part of the manual. Part 3 – Level Flight Aerodynamics. This part is devoted to lift analysis, lift augmentation, drag, stalling and the thrust and power essential to maintain level flight. Part 4 – Stability. This part examines in detail the complex topics of aeroplane static and dynamic stability. www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come xxiv PREFACE Part 5 – Manoeuvre Aerodynamics. Level-flight manoeuvres such as turns and dives together with the aerodynamics of climbs and descents are the main topics of this part of the manual. Part 6 – Other Aerodynamic Considerations. High-speed flight, including supersonic flight, is explained in detail because of the EASA syllabus requirements; despite the fact that there are no supersonic transport aeroplanes any longer. CPL examination candidates should ignore Chapter 15 – High Speed Flight. Part 7 – Conclusion. This part includes a summary of the major components of the Principles of Flight syllabus and the solutions to all of the self-assessed exercises The author would like to stress that, although The Principles of Flight for Pilots is directed towards explaining basic theory of flight, the explanations, advice and interpretations given are his alone, and not necessarily shared by EASA or any other legislative body. It does not seek to replace any of the works mentioned in the bibliography, but should be used in conjunction with them. References quoted in the text of the manual were current in May 2010. Every effort has been made to ensure that the information contained in The Principles of Flight for Pilots was up-to-date at the time of publication; but readers are reminded that every document listed in the bibliography on which this book is based is subject to amendment. It is true that major changes of policy are not implemented without adequate warning and publicity; but minor alterations could escape notice and every reader is advised to pay careful attention to any amendment list issued by the CAA and EASA. No responsibility is accepted for any errors or discrepancy. P. J. Swatton www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come Acknowledgements My grateful thanks once again go to David Webb who has willingly given his expert advice and contributed in no small part by drawing all of the illustrations using his computer. The Principles of Flight Examination This manual contains the information required to cover the ATPL (A) and CPL (A) Learning Objectives for the EASA subject 081 - Principles of Flight. The examination in this subject is from 0930 to 1030 on the first day of the examinations for ATPL candidates and contains 40 questions. For CPL candidates the examination is from 0900 to 0945 on the first day of the examinations and contains 34 questions. The main reference documents for the Principles of Flight examination are: (1) EU-OPS1 (2) AMC Definitions (3) CS-23 Normal and Commuter Aeroplanes (4) CS-25 Large Aeroplanes (5) Civil Aviation Aeronautical Information Circulars www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come List of Abbreviations a Acceleration A Cross-Sectional Area A/F Airfield A and AEE The Aeroplane and Armament Experimental Establishment aal above aerodrome level AC Aerodynamic Centre AFM Aeroplane Flight Manual agl above ground level AIC Aeronautical Information Circular AIP Aeronautical Information Package amsl above mean sea level AoA Angle of Attack AR Aspect Ratio ASD Accelerate/Stop Distance ASDR Accelerate/Stop Distance Required ASIR Airspeed Indicator Reading ATM Aerodynamic Twisting Moment AUM All-Up Mass AUW All-Up Weight BHP Brake Horsepower BRP Brake Release Point C of A Certificate of Airworthiness CP Centre of Pressure CAA Civil Aviation Authority CAP Civil Aviation Publication CAS Calibrated Airspeed CD Coefficient of Drag CDI Coefficient of induced drag CDP Coefficient of parasite drag CD A Mean Coefficient of drag in the air C DG Mean Coefficient of drag on the ground CF Centrifugal Force CG Centre of Gravity CL Coefficient of Lift CLmax Maximum Coefficient of Lift Cn Yawing Moment Coefficient CM Pitching Moment CM0 Pitching Moment at the Zero Lift value www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come xxviii LIST OF ABBREVIATIONS CP Critical Point CS Certification Standards Document CSU Constant Speed Unit CTM Centrifugal Twisting Moment DA Density Altitude EAS Equivalent Airspeed EASA European Aviation Safety Agency F Force FAA Federal Aviation Administration FAR Federal Aviation Regulations FLL Field-length-limited g Acceleration due to gravity GE Ground Effect G/S Groundspeed IAS Indicated Airspeed IAT Indicated Air Temperature ICAO International Civil Aviation Organisation ISA International Standard Atmosphere JAA Joint Aviation Authority JAR Joint Aviation Requirements JSA Jet Standard Atmosphere kg kilogram(s) km kilometre(s) kt nautical miles per hour (knots) KE Kinetic Energy L Rolling moment LD Landing Distance LE Leading Edge LER Leading Edge Radius LSS Local Speed of Sound m Mass M Mach Number M/S Mass per unit area of a wing (wing loading) MAC Mean Aerodynamic Chord MCDR Critical Drag Rise Mach Number MCRIT Critical Mach Number MDET Detachment Mach Number MFS The True Mach Number of an aeroplane ML The Local Mach Number MMO Maximum Operating Mach Number n Load Factor N Newton NP Neutral Point OAT Outside Air Temperature PCU Propeller Control Unit PIO Pilot-Induced Oscillation ps Static Pressure pt Total Pressure q Dynamic Pressure RAF Relative Airflow RAS Rectified Airspeed Re Reynold’s Number www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come LIST OF ABBREVIATIONS xxix ROC Rate of Climb ROD Rate of Descent RPM Revolutions per Minute S Wing Area SG Specific Gravity SM Static Margin SP Stagnation Point STOL Short-field take-off and landing TAS True Airspeed TAT Total Air Temperature TE Trailing Edge THS Trimmable Horizontal Stabilizer TOD Take-off Distance TOM Take-Off Mass TOR Take-off Run TOW Take-Off Weight TP Trim Point VA Design Manoeuvring Speed Vb Basic Stalling Speed VB Design Speed for maximum gust intensity VC Design Cruising Speed VCLmax CAS of the maximum CL. VD Design Diving Speed VDD Design Drag Devices speed VEF The assumed speed of engine failure during the take-off ground run VF Design Flap Speed VFE Maximum speed for flying with flaps extended VFO Maximum speed for operating the flaps VIMD The velocity of minimum drag VIMP The velocity of minimum power VLE The maximum speed with the undercarriage (landing gear) extended VLO The maximum speed at which the undercarriage (landing gear) may be operated VM Manoeuvre Stalling Speed. VMC The minimum control speed with the critical power unit inoperative VMCG The minimum control speed on the ground with the critical power unit inoperative VMCL The minimum control speed on the approach to land VMCL(1out) The minimum control speed on the approach to land with one engine inoperative VMCL-2 The minimum control speed on the approach to land with two engines inoperative VIMD Velocity of minimum drag IAS VIMP Velocity of minimum power IAS VMD Velocity of minimum drag TAS VMO The maximum operating speed VMP Velocity of minimum power TAS VMS The minimum stalling speed VMS0 The minimum stalling speed with the flaps in the landing setting VMS1 The minimum stalling speed for the case under consideration VMU The minimum unstick speed VNE Never exceed speed VNO Maximum normal operating speed. VO The speed of the freestream airflow over an aerofoil surface VRA The rough-air or turbulence speed VREF The reference landing speed www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come xxx LIST OF ABBREVIATIONS VS Stalling speed CAS VS0 The stalling speed CAS with the flaps at the landing setting VS1 The stalling speed CAS for the configuration under consideration VS1g Stalling speed CAS at 1g VSR Reference stalling speed CAS VSR0 Reference stalling speed CAS in the landing configuration VSR1 Reference stalling speed CAS for the configuration under consideration VSW The speed at which the onset of the natural or artificial stall warning activates VX The speed at which the maximum gradient of climb will be achieved VY The speed at which the maximum rate of climb will be achieved WC Wind Component WED Water-Equivalent Depth www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come Weight and Mass Before starting any calculations it is necessary to explain the difference between a Newton (N), which is a unit of force, a kilogram (kg), which is a unit of mass and weight, which is the force acting on a body by gravity. Most of us know what we mean when we use the term weight and become confused when the term mass is used in its place. In all of its documents the JAA consistently use the term mass whereas the majority of aviation documents produced by the manufacturers use the term weight. The following are the definitions of each of the terms and should help clarify the situation: Mass The quantity of matter in a body as measured by its inertia is referred to as its mass. It determines the force exerted on that body by gravity, which is directly proportional to the mass. Gravity varies from place to place and also decreases with increased altitude above mean sea level. Weight The force exerted on a body by gravity is known as its weight and is dependent on the mass of the body and the strength of the gravitational force for its value. Weight = mass in kg × gravity in Newtons. Thus, the weight of a body varies with its location and elevation above mean sea level but the mass does not change for the same body. The change of weight of an object due to its changed location is extremely small, even at 50 000 ft above mean sea level, however, it is technically incorrect and the term mass should be used. For the purposes of this manual the terms weight and mass are interchangeable. In the questions asked in the JAA examinations the word mass is used most of the time. IEM OPS 1.605. The Newton A Newton is a unit of force, which equals mass × acceleration. 1 Newton = 1 kg × 1 m/s2. At the surface of the Earth the acceleration due to gravity equals 9.81 m/s2. Thus, the force acting on 1 kg at the Earth’s surface is 9.81 Newtons. To simplify calculations in the examination the acceleration due to gravity is given as 10 m/s2 therefore 1 kg is equal to 10 Newtons. www.ASEC.ir P1: FCG/SPH P2: FCG/SPH QC: FCG/SPH T1: SPH FM BLBK308/Swatton August 14, 2010 12:54 Printer Name: Yet to Come www.ASEC.ir P1: OTA/XYZ P2: ABC c01 BLBK308/Swatton August 11, 2010 19:22 Printer Name: Yet to Come Part 1 The Preliminaries www.ASEC.ir P1: OTA/XYZ P2: ABC c01 BLBK308/Swatton August 11, 2010 19:22 Printer Name: Yet to Come www.ASEC.ir P1: OTA/XYZ P2: ABC c01 BLBK308/Swatton August 11, 2010 19:22 Printer Name: Yet to Come 1 Basic Principles 1.1 The Atmosphere The Earth’s atmosphere is the layer of air that surrounds the planet and extends five hundred miles upwards from the surface. It consists of four concentric gaseous layers, the lowest of which is the troposphere in which all normal aviation activities take place. The upper boundary of the troposphere is the tropopause, which separates it from the next gaseous layer, the stratosphere. The next layer above that is the mesosphere and above that is the thermosphere. The height of the tropopause above the surface of the earth varies with latitude and with the season of the year. It is lowest at the poles being approximately 25 000 feet above the surface of the Earth and 54 000 feet at the Equator. These heights are modified by the season, being higher in the summer hemisphere and lower in the winter hemisphere. Above the tropopause the stratosphere extends to a height of approximately one hundred thousand feet. Although these layers of the atmosphere are important for radio-communication purposes, because of the ionised layers present, they are of no importance to the theory of flight. Since air is compressible the troposphere contains the major part of the mass of the atmosphere. The weight of a column of air causes the atmospheric pressure and density of the column to be greatest at the surface of the Earth. Thus, air density and air pressure decrease with increasing height above the surface. Air temperature also decreases with increased height above the surface until the tropopause is reached above which the temperature remains constant through the stratosphere. 1.2 The Composition of Air Air is a mixture of gases the main components of which are shown in Table 1.1. Water vapour in varying quantities is found in the atmosphere up to a height of approximately 30 000 ft. The amount in any given air mass is dependent on the air temperature and the passage of the air mass in relationship to large areas of water. The higher the air temperature the greater the amount of water vapour it can hold. 1.2.1 The Measurement of Temperature Centigrade Scale. The Centigrade scale is normally used for measuring the air temperature and for the temperature of aero-engines and their associated equipment. On this temperature scale water freezes at 0◦ and boils at 100◦ at mean sea level. The Principles of Flight for Pilots P. J. Swatton  C 2011 John Wiley & Sons, Ltd www.ASEC.ir 3 P1: OTA/XYZ P2: ABC c01 BLBK308/Swatton August 11, 2010 19:22 Printer Name: Yet to Come 4 BASIC PRINCIPLES Table 1.1 Gas Components of the Air.