Flight Environment, Flight Forces and Steady Flight Performance: The atmosphere as flight environment. The International Standard Atmosphere Model. The Force and Moment Systems of an Aircraft. Steady state performance.
Static Longitudinal Stability and Control (Stick Fixed): Degree of freedom of rigid bodies in space. Static Longitudinal stability - Stick fixed. Effects of fuselage and nacelle - Influence of CG location - Power effects - Stick fixed neutral point.
Static Longitudinal Stability and Control-Stick free: Introduction, Hinge moment parameters, Control surface floating characteristics and aerodynamic balance, Estimation of hinge moment parameters, The trim tabs, Stick-free Neutral point, Stick force gradient in unaccelerated flight, Restriction on aft C.G.
Static Directional and Lateral Stability and Control Static directional stability rudder fixed, Contribution of airframe components, Directional control. Rudder power, Stick-free directional stability, Requirements for directional control, Rudder lock, Dorsal fin. One engine inoperative condition. Weather cocking effect. Static lateral stability. Estimation of dihedral effect. Effect of wing sweep, flaps, and power. Lateral control, Estimation of lateral control power, Aileron control forces, Balancing the aileron. Coupling between rolling and yawing moments. Adverse yaw effects. Aileron reversal.
Equations of Motions (EOMs) Derivation of rigid body equations of motion, Orientation and position of the airplane, gravitational and thrust forces, Small disturbance theory. Aerodynamic force and moment representation, Derivatives due to change in forward speed, Derivatives due to the pitching velocity, Derivatives due to the time rate of change of angle of attack, Derivatives due to rolling rate, Derivatives due to yawing rate.
Dynamic Stability Dynamic longitudinal stability. Types of modes of motion: phugoid motion, short period motion. Routh’s stability criteria. Factors affecting period and damping of oscillations. Dynamic lateral and directional stability. Response to aileron step-function, side-slip excursion. Dutch roll and Spiral instability. Auto- rotation and spin. Stability derivatives for lateral and directional dynamics.
Course Outcomes:
At the end of the course the student will be able to:
1. CO1: Apply the basic concepts of aircraft performance, and stability.
2. CO2: Use static stability concepts and stability parameters.
3. CO3: Estimate the dynamic stability derivatives.
Question paper pattern:
• The question paper will have ten full questions carrying equal marks.
• Each full question will be for 20 marks.
• There will be two full questions (with a maximum of four sub- questions) from each module.
• Each full question will have sub- question covering all the topics under a module.
• The students will have to answer five full questions, selecting one full question from each module.
Textbook/s
1 Airplane Performance stability and Control Perkins, C.D., and Hage, R.E John Wiley Son Inc, New York 1988
2 Flight Stability and Automatic Control Nelson, R.C McGraw-Hill Book Co 2007
Reference Books
1 Performance, Stability, Dynamics and Control of Airplanes Bandu N. Pamadi AIAA 2nd Edition Series, 2004
2 Introduction to flight John D. Anderson, Jr McGraw-Hill 2000
3 The Principles of the Control and Stability of Aircraft W.J. Duncan Cambridge University Press 2016
4 Dynamics of Flight Stability and Control Etkin, B John Wiley, New York 1982