Aircraft Flight Dynamics and ControlISBN: 9781118646816
306 pages
October 2013

This book covers the physical and mathematical fundamentals of aircraft flight dynamics as well as more advanced theory enabling a better insight into nonlinear dynamics. This leads to a useful introduction to automatic flight control and stability augmentation systems with discussion of the theory behind their design, and the limitations of the systems. The author provides a rigorous development of theory and derivations and illustrates the equations of motion in both scalar and matrix notation.
Key features:
 Classical development and modern treatment of flight dynamics and control
 Detailed and rigorous exposition and examples, with illustrations
 Presentation of important trends in modern flight control systems
 Accessible introduction to control allocation based on the author's seminal work in the field
 Development of sensitivity analysis to determine the influential states in an airplane's response modes
 End of chapter problems with solutions available on an accompanying website
Written by an author with experience as an engineering test pilot as well as a university professor, Aircraft Flight Dynamics and Control provides the reader with a systematic development of the insights and tools necessary for further work in related fields of flight dynamics and control. It is an ideal course textbook and is also a valuable reference for many of the necessary basic formulations of the math and science underlying flight dynamics and control.
Glossary xv
1 Introduction 1
1.1 Background 1
1.2 Overview 2
1.3 Customs and Conventions 6
2 Coordinate Systems 7
2.1 Background 7
2.2 The Coordinate Systems 7
2.2.1 The inertial reference frame, FI 7
2.2.2 The earthcentered reference frame, FEC 8
2.2.3 The earthfixed reference frame, FE 8
2.2.4 The localhorizontal reference frame, FH 8
2.2.5 Bodyfixed reference frames, FB 10
2.2.6 Windaxis system, FW 12
2.2.7 Atmospheric reference frame 12
2.3 Vector Notation 13
2.4 Customs and Conventions 14
2.4.1 Latitude and longitude 14
2.4.2 Body axes 14
2.4.3 'The' bodyaxis system 14
2.4.4 Aerodynamic angles 15
3 Coordinate System Transformations 17
3.1 Problem Statement 17
3.2 Transformations 18
3.2.1 Definitions 18
3.2.2 Direction cosines 18
3.2.3 Euler angles 21
3.2.4 Euler parameters 25
3.3 Transformations of Systems of Equations 26
3.4 Customs and Conventions 27
3.4.1 Names of Euler angles 27
3.4.2 Principal values of Euler angles 27
4 Rotating Coordinate Systems 31
4.1 General 31
4.2 Direction Cosines 34
4.3 Euler Angles 34
4.4 Euler Parameters 36
4.5 Customs and Conventions 38
4.5.1 Angular velocity components 38
5 Inertial Accelerations 43
5.1 General 43
5.2 Inertial Acceleration of a Point 43
5.2.1 Arbitrary moving reference frame 43
5.2.2 Earthcentered moving reference frame 46
5.2.3 Earthfixed moving reference frame 46
5.3 Inertial Acceleration of a Mass 47
5.3.1 Linear acceleration 48
5.3.2 Rotational acceleration 49
5.4 States 53
5.5 Customs and Conventions 53
5.5.1 Linear velocity components 53
5.5.2 Angular velocity components 54
5.5.3 Forces 54
5.5.4 Moments 56
5.5.5 Groupings 56
6 Forces and Moments 59
6.1 General 59
6.1.1 Assumptions 59
6.1.2 State variables 60
6.1.3 State rates 60
6.1.4 Flight controls 60
6.1.5 Independent variables 62
6.2 NonDimensionalization 62
6.3 NonDimensional Coefficient Dependencies 63
6.3.1 General 63
6.3.2 Altitude dependencies 64
6.3.3 Velocity dependencies 64
6.3.4 Angleofattack dependencies 64
6.3.5 Sideslip dependencies 66
6.3.6 Angular velocity dependencies 68
6.3.7 Control dependencies 69
6.3.8 Summary of dependencies 70
6.4 The Linear Assumption 71
6.5 Tabular Data 71
6.6 Customs and Conventions 72
7 Equations of Motion 75
7.1 General 75
7.2 BodyAxis Equations 75
7.2.1 Bodyaxis force equations 75
7.2.2 Bodyaxis moment equations 76
7.2.3 Bodyaxis orientation equations (kinematic equations) 77
7.2.4 Bodyaxis navigation equations 77
7.3 WindAxis Equations 78
7.3.1 Windaxis force equations 78
7.3.2 Windaxis orientation equations (kinematic equations) 80
7.3.3 Windaxis navigation equations 81
7.4 SteadyState Solutions 81
7.4.1 General 81
7.4.2 Special cases 83
7.4.3 The trim problem 88
8 Linearization 93
8.1 General 93
8.2 Taylor Series 94
8.3 Nonlinear Ordinary Differential Equations 95
8.4 Systems of Equations 95
8.5 Examples 97
8.5.1 General 97
8.5.2 A kinematic equation 99
8.5.3 A moment equation 100
8.5.4 A force equation 103
8.6 Customs and Conventions 105
8.6.1 Omission of Δ 105
8.6.2 Dimensional derivatives 105
8.6.3 Added mass 105
8.7 The Linear Equations 106
8.7.1 Linear equations 106
8.7.2 Matrix forms of the linear equations 108
9 Solutions to the Linear Equations 113
9.1 Scalar Equations 113
9.2 Matrix Equations 114
9.3 Initial Condition Response 115
9.3.1 Modal analysis 115
9.4 Mode Sensitivity and Approximations 120
9.4.1 Mode sensitivity 120
9.4.2 Approximations 123
9.5 Forced Response 124
9.5.1 Transfer functions 124
9.5.2 Steadystate response 125
10 Aircraft Flight Dynamics 127
10.1 Example: Longitudinal Dynamics 127
10.1.1 System matrices 127
10.1.2 State transition matrix and eigenvalues 127
10.1.3 Eigenvector analysis 129
10.1.4 Longitudinal mode sensitivity and approximations 132
10.1.5 Forced response 137
10.2 Example: Lateral–Directional Dynamics 140
10.2.1 System matrices 140
10.2.2 State transition matrix and eigenvalues 140
10.2.3 Eigenvector analysis 142
10.2.4 Lateral–directional mode sensitivity and approximations 144
10.2.5 Forced response 148
11 Flying Qualities 151
11.1 General 151
11.1.1 Method 152
11.1.2 Specifications and standards 155
11.2 MILF8785C Requirements 156
11.2.1 General 156
11.2.2 Longitudinal flying qualities 157
11.2.3 Lateral–directional flying qualitities 158
12 Automatic Flight Control 169
12.1 Simple Feedback Systems 170
12.1.1 Firstorder systems 170
12.1.2 Secondorder systems 172
12.1.3 A general representation 177
12.2 Example Feedback Control Applications 178
12.2.1 Roll mode 178
12.2.2 Shortperiod mode 184
12.2.3 Phugoid 188
12.2.4 Coupled roll–spiral oscillation 198
13 Trends in Automatic Flight Control 209
13.1 Overview 209
13.2 Dynamic Inversion 210
13.2.1 The controlled equations 212
13.2.2 The kinematic equations 215
13.2.3 The complementary equations 221
13.3 Control Allocation 224
13.3.1 Background 224
13.3.2 Problem statement 225
13.3.3 Optimality 231
13.3.4 Suboptimal solutions 232
13.3.5 Optimal solutions 235
13.3.6 Nearoptimal solutions 241
Problems 243
References 244
A Example Aircraft 247
Reference 253
B Linearization 255
B.1 Derivation of Frequently Used Derivatives 255
B.2 Nondimensionalization of the Rolling Moment Equation 257
B.3 Body Axis ZForce and Thrust Derivatives 258
B.4 Nondimensionalization of the ZForce Equation 260
C Derivation of Euler Parameters 263
D Fedeeva's Algorithm 269
Reference 272
E MATLAB Commands Used in the Text 273
E.1 Using MATLAB 273
E.2 Eigenvalues and Eigenvectors 274
E.3 StateSpace Representation 274
E.4 Transfer Function Representation 275
E.5 Root Locus 277
E.6 MATLAB® Functions (mfiles) 277
E.6.1 Example aircraft 278
E.6.2 Mode sensitivity matrix 278
E.6.3 Cutandtry root locus gains 278
E.7 Miscellaneous Applications and Notes 280
E.7.1 Matrices 280
E.7.2 Commands used to create Figures 10.2 and 10.3 281
Index 283
Wayne Durham, Virginia Polytechnic Institute and State University, USA
Wayne Durham is an Associate Professor Emeritus in the College of Engineering at Virginia Polytechnic Institute and State University. His area of research focuses on aircraft flight dynamics and control and he teaches a course (AOE 5214) on this subject at Virginia Tech University. He previously worked as a flight instructor at various Navy Schools in the US.