Course outline

This course is intended to serve a diverse audience of master students who are interested in understanding and utilizing the concepts of flight dynamics. The course provides to the student the basic principles based on a classical analytical approach. The concepts of controllability and maneuverability are detailed starting from the definition of stability and control of the equilibrium states. Equations for the estimation of hinge moments and stick force in steady and maneuvering flight are given. The equations of motion are then extended to unsteady flight and a detailed analytical model is derived for dynamic stability analysis, including an interpretation of stability and control derivatives. Modal response of the vehicle in the longitudinal and lateral-directional plane is also reconstructed. The problems inherent to the evaluation of the flying qualities of a fixed-wing aircraft and the elements of parameter identification are also introduced. Finally, open and closed loop response to controls is discussed both in time and frequency domain

Llist of topics

Section 1 - Flight dynamics (basic theory)

-       Reference frames (definitions)

-       Euler angles and rotation matrices

-       Longitudinal static stability (isolated wing and tailless aircraft)

-       Longitudinal static stability (wing+body configuration)

-       Longitudinal static stability (complete aircraft)

-       Stick fixed neutral point (definition) and shift of center of gravity

-       Longitudinal control (equations and graphs for elevator deflection)

-       Hinge moments and stick forces (equations and graphs, the effect of airspeed and aircraft design parameters)

-       Trim/balance/anti-balance/servo tabs

-       Stick free neutral point (equations and related graphs)

-       Aircraft maneuverability (quasi-steady analysis and correlation of angular rate and load factor)

-       Aircraft maneuverability (elevator and stick gradients)

-       Comprehensive design criteria (assessment grid)

-       Rigid body dynamics (derivation of equations of motion based on momentum and angular momentum)

-       Small perturbation theory (linear formulation)

-       Aerodynamic and control derivatives (definitions and examples)

-       Lateral static stability (Clbeta)

-       Directional static stability (Cnbeta)

-       Lateral-directional aerodynamic derivatives (Clp, Cnp, Clr, Cnr)

-       Modal response and dynamic stability (longitudinal plane)

-       Modal response and dynamic stability (lateral-directional plane)

-       Open loop longitudinal time domain response to elevator input (complete and reduced order models)

-       Flexible aircraft dynamics (static and dynamic effects)

Section 2 - Control, identification and advanced flight dynamics

-       Flying and handling qualities (civil and military standards)

-       Flight simulators (numerical direct simulation of aircraft dynamics)

-       The design of flight control systems: theory for PID controls (advantages and limitations) and stability issues for the controlled aircraft (closed loop control)

-       Type of controls (classification of controls for performance and robustness, optimal and adaptive controls)

-       Stability Augmentation Systems (SAS) and Modal Suppression Systems (MSS)

-       Methods for system identification (time and frequency domain methods)

-       Identification methods based on flight tests (instrumentation, measurement, data processing and analysis) and model validation

-       Identification methods based on wind tunnel experiments (static tests, free/forced oscillatory experiments, rotary balance)

-       High angle of attack flight (design issues)

-       Rapid roll maneuver (Phillips theory)

Section 3 - Exercises and other lectures

2nd order systems

Three-Dimensional Rotations

-       Direction cosine matrix

-       Angular velocity

-       Rotation tensor

-       Change of basis

-       Composition of rotations

-       Non-vectorial parameterization of rotations (Euler parameters, Euler angles)

Comprehensive Equations of Motion

-       Dynamic equations

-       Equation of motion with small perturbations

-       Linearization and decoupling

Dynamic stability

-       Longitudinal dynamics (models reduction)

-       Lateral-directional dynamics (models reduction)

Generalized maneuvers and trim

Control

-       Pitch stability augmentation systems

-       Lateral stability augmentation systems

-       Optimal control

Identification and applications

The written examination is a comprehensive test in English language that assesses the examinee's knowledge of flight dynamics.

The test takes usually up to 3 hours and it is performed by the examinee in written form as a technical dissertation of 4 specific topics or questions:

-       2 topics: (Section 1) Flight dynamics (basic theory)

-       1 topic: (Section 2) Control, identification and advanced flight dynamics (high angle of attack flight and wind tunnel experimental techniques)

-       1 topic: (Section 3) Exercises and other lectures

Each topic must be discussed in detail, with an adequate level of understanding and description (the use of drawings and flow charts may be useful). The use of English language will not be evaluated but the lack of clarity may compromise the result of the exam. No more than 2 pages can be allocated for each topic.