Dynamic analysis has changed dramatically during recent decades, with the introduction of powerful personal computers and scientific programming languages. Analysis programs have become so pervasive that it can be assumed that all students and practicing engineers working on aircraft flight dynamics have access to them. Therefore, this book presents the principles, derivations, and equations of flight dynamics with frequent reference to computed examples, and it includes MATLAB code for six-degree-of-freedom simulation and linear system analysis.

By using common notation and not assuming a strong background in aeronautics, *Flight Dynamics* is accessible to a wide variety of readers. Introductions to aerodynamics, propulsion, structures, and the atmospheric and gravitational environment precede the development of the aircraft's dynamic equations. Systeme International (SI) units are used for the majority of the text. These units take better advantage of decimal arithmetic than U.S. Customary Units, the majority of world industry and academe uses them, and virtually all high school and college students learn physics, chemistry, and mathematics with SI units.

*Flight Dynamics* is organized in seven chapters and an epilogue.

__Introduction__(Chapter 1) presents a summary of the important elements of the aircraft and its systems; examples of about a dozen aircraft ranging from an uninhabited air vehicle, through general aviation and transport aircraft, to combat aircraft, trans/supersonic aircraft, and the space shuttle; and an overview of the mechanics of flight.__Exploring the Flight Envelope__(Chapter 2) describes the flight environment and the essential ingredients for steady flight.__The Dynamics of Aircraft Motion__(Chapter 3) provides comprehensive coverage of the nonlinear equations of motion, expressed in various coordinate systems and with alternative angular measures (direction cosines and quaternions).__Methods of Analysis and Design__(Chapter 4) addresses the fundamental equations used for both classical and modern analysis of aircraft stability and control, including stochastic methods, and it presents introductions to aeroelasticity, flying qualities criteria, and flight control system design.__Longitudinal Motions__(Chapter 5) presents motions in the vertical plane in a novel fashion, building insight with reduced-order linear models derived from the complete set.__Lateral-Directional Motions__(Chapter 6) parallels the previous chapter, describing rolling and yawing motion with increasingly complex models, and subjecting each to a series of analyses.__Coupled Longitudinal and Lateral-Directional Motions__(Chapter 7) goes into considerable detail about the ways in which motions interact, using bifurcation analysis, linear analysis, and nonlinear simulation, and it introduces several approaches to nonlinear control system design that are essential for high-angle-of-attack flight.- The
__Epilogue__briefly discusses the implications of the book.

The LTI models can be subjected to various linear analyses in the MATLAB program SURVEY.m, including model order reduction through truncation or residualization, transient response, equilibrium response, controllability and observability, Bode, Nyquist, and Nichols plots, and root locus analysis. Longitudinal and lateral-directional motions can be analyzed separately or under fully coupled flight conditions. The FLIGHT.m and SURVEY.m programs are heavily commented, and they serve a tutorial role on their own.

A new chapter on flight control design gives comprehensive coverage to techniques that apply for a wide range of linear and nonlinear dynamic models with analog or digital systems and cannot be found elsewhere.

- Chapter 8,
__Flight Control Design__, provides a unique approach to designing closely integrated multivariable flight control systems. Topics include- Response to command inputs
- Optimal feedback control and state estimation
- Parameter identification
- Classical stability margins
- Control system robustness
- Gain scheduling
- Neural network control
- Nonlinear-inverse-dynamic control
- Adaptive control via machine learning
- System failure detection, identification, and reconfiguration

In addition to the business jet mathematical model used throughout the book, a model for an advanced jet trainer is included. Future additions include models for a narrow-body jet transport with conventional and electric propulsion, a supersonic transport, and a hypersonic cruiser. These new models are formulated with the program, ModelBuild.m, which uses the methods described in Chapters 4 and 5 of *Flight Dynamics* to formulate 6DOF descriptions of dynamics.

While covering all the material in the book typically would require a two-semester course, a one-term undergraduate course can be based upon portions of the book, leaving the more advanced topics for independent reading. *Flight Dynamics* is written with a physics-based evolution of topics; a more flexible organization of material may be preferred for lectures and assignments. With this in mind, guidelines for first and second courses on flight dynamics and control are given. Lecture slides, assignments, and internet links for a third/fourth-year undergraduate course can be found online below and at Flight Dynamics, Second Edition.

While the course focuses on the *Science and Mathematics* of flight dynamics, historical antecedents are presented as *Case Studies* in aircraft performance, stability, and control. The science and mathematics component is based on * Flight Dynamics, Second Edition*. The case studies were initially motivated by

"A monumental piece of work. Its comprehensive treatment of flight dynamics makes it the broadest in its class and constitutes a major contribution to the aerospace community. Destined for students' shelves as well as mine, it will also be valuable as the methodological companion to the aircraft designer, flight test engineer, and pilot."-- Eric Feron, Massachusetts Institute of Technology (currently, Georgia Institute of Technology)

"This book is definitely a significant contribution to the field. It is more comprehensive than any other work on flight dynamics I have seen; it includes newer concepts, such as neural nets and wind shear effects, some of these reflecting the author's own research; and it gives a very broad view of flight dynamics. Not only is it a fine textbook on flight dynamics, but it is so thorough and so well written that it will undoubtedly catch the attention of practicing engineers and airplane enthusiasts."-- Haim Baruh, Rutgers University

Review by John Hodgkinson, AeroArts LLC, for the *AIAA Journal*

Review by Eric Feron, Georgia Institute of Technology, for the *IEEE Control Systems Magazine*

Review by John Valasek, Texas A&M University, for the *Journal of Guidance, Control, and Dynamics*

"This is an excellent book that any flight controls or aviation engineer will find more than just useful. It provides a pretty complete treatment of the state variable approach and should serve as an excellent starting point for those wanting to design actual controllers for aircraft." -- *Anon., Amazon*

"This is an excellent book, I remembered it from university days and recently re-purchased it for work (flight simulator engineer). It covers almost every aspect of fixed wing aircraft dynamics you might want, and of course a fair amount reads across to rotary wing vehicles. The appendices summarising the Matlab models provided and relevant NASA papers are useful. The book language and notation doesn't assume too much prior specific aeronautics experience so it can be shared with colleagues from a different background." -- *Anon, Amazon*

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Robert F. Stengel is Professor Emeritus and former Associate Dean of Engineering and Applied Science at Princeton University. He is the author of *Optimal Control and Estimation* (Dover, 1994). He was principal designer of the Apollo Lunar Module manual attitude control logic.

Last updated on March 21, 2022. Copyright 2022 by Robert F. Stengel. All rights reserved.