Sideslip | Flight Mechanics | GATE Aerospace

For Video Lecture of this presentation: https://youtu.be/u7bp9IJqRVM

The topics covered in this session are, Slip: Types of slip, Sideslip angle, Sideslip angle sign conventions, restoring yaw moments, physical significance, Calculation of sideslip angle, Measurement of sideslip.

Attention! "Gate Aerospace Engineering aspirants", A virtual guide for gate aerospace engineering is provided in "Age of Aerospace" blog for helping you meticulously prepare for gate examination. Respective notes of individual subjects are provided as 'Embedded Google Docs' which are frequently updated. This comprehensive guide is intended to efficiently serve as an extensive collection of online resources for "GATE Aerospace Engineering" which can be accessed free of cost. Use the following link to access the study material
https://ageofaerospace.blogspot.com/p/gate-aerospace.html

1. FLIGHT MECHANICS Presented by - Ganesh Natarajan S Target Audience : Gate Aerospace, Aeronautical and Aerospace Engineering Students, etc. SIDESLIP β V ∞

2. CORE TOPICS Basics: Atmosphere: Properties, standard atmosphere. Classification of aircraft. Airplane (fixed wing aircraft) configuration and various parts. Pressure altitude; equivalent, calibrated, indicated air speeds; Primary flight instruments: Altimeter, ASI, VSI, Turn-bank indicator. Angle of attack, sideslip ; Roll, pitch & yaw controls. Aerodynamic forces and moments . Airplane performance: Drag polar; takeoff and landing; steady climb & descent; absolute and service ceiling; range and endurance, load factor, turning flight, V-n diagram. Winds: head, tail & cross winds . Static stability: Stability & control derivatives; longitudinal stick fixed & free stability; horizontal tail position and size; directional stability, vertical tail position and size; lateral stability. Wing dihedral, sweep & position; hinge moments, stick forces . SPECIAL TOPICS Dynamic stability: Euler angles; Equations of motion; Decoupling of longitudinal and lateral-directional dynamics; longitudinal modes; lateral-directional modes. SYLLABUS

3. SIDESLIP

4. Slip: A slip is an aerodynamic state where an aircraft is moving somewhat sideways as well as forward relative to the oncoming airflow or relative wind . Slip: Un-coordinated Flight. Types of Slip Forward Slip : reduce height Sideslip : move the aircraft sideways Crab method Wing low method Slip & its types Motion Imagery Standards Board (MISB) / Public domain

5. Sideslip Angle Definition The angle between the relative wind (V ∞ ) and the projection of the airplane’s longitudinal axis is known as the sideslip angle The sideslip angle is symbolized as “ β ”. Co-ordinated Flight - zero sideslip angle. β V ∞ Relative Headwind Relative Crosswind Relative Wind

6. + β V ∞ - β V ∞ Sideslip Angle Positive Sideslip Angle Negative Sideslip Angle

7. V ∞ - N V ∞ Restoring Yawing Moment Positive Yawing Moment Negative Yawing Moment + N β = 0

8. Physical Significance: Crosswind landings In crosswind conditions, the pilot is required to fly at a sideslip angle in order to maintain alignment with the runway . [ Transport airplanes 15.5 m/s ]   Mysid / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

9. Calculation of Sideslip Angle Y

10. Sideslip Angle Formula β = sin -1   i.e. sin θ =   α = tan -1   i.e. tan θ =   Similarly If the sideslip and angle of attack are smaller than. i.e. < 15° β =   α =   Where V = (u 2 + v 2 +w 2 ) 1/2 *The value of α and β values are in radians* The sideslip ( β ) and angle of attack ( α ) can be defined in in terms of the velocity components, using trigonometry

11. Federal Aviation Administration / Public domain Sideslip Measurement Yaw String Turn & Slip Indicator

12. Book Reference Flight stability and automatic control (2 nd Edition ), Dr. Robert C. Nelson; Pg.No : (21 & 30). Pilot's handbook of aeronautical knowledge 2016 - Chapter 5: Aerodynamics of flight (5-18) Pg No: (117/524) SIDESLIP

13. Copyright Notice: Images used in this presentation are sourced from pixabay.com under “ Pixabay License” which are “ Free for commercial use and No attribution required ” category (or) from other sources, in which case appropriate attributions are provided.