1. Aeronautics K Sudhakar H Arya A Isaacs
Centre for Aerospace Systems Design & Engineering
Department of Aerospace Engineering
IIT Bombay, Mumbai

2. Dept of Aerospace Engineering, IIT-B
It Comes in All Shapes
What makes them fly?
Dept of Aerospace Engineering, IIT-B
12/6/2018

3. Dept of Aerospace Engineering, IIT-B
Contents
Principles of Flight
Airfoil
Wing
Wing + Horizontal tail
Wing + Horizontal tail + Vertical Tail
Mini Aerial Vehicles
Mini/Micro Aerial Vehicles
Hobby flying / RC Models
Autonomous Flight
Navigation/Guidance/Control
Sensors/Actuators
Dept of Aerospace Engineering, IIT-B
12/6/2018

4. Dept of Aerospace Engineering, IIT-B
Why Airfoil ? V
Drag
Drag V
Airfoil : Shape that offers very low drag
Dept of Aerospace Engineering, IIT-B
12/6/2018

5. Dept of Aerospace Engineering, IIT-B
Lift & Drag
Lift = 0.5  V2 C a 
Moment = 0.5  V2 C2 d
Moment is about 0.25 C
Lift
Moment V 
Drag C
- Angle of Attack
Dept of Aerospace Engineering, IIT-B
12/6/2018

6. Dept of Aerospace Engineering, IIT-B
Lift & Drag V 
Lift
Drag
- Angle of Attack
Lift = 0.5  V2 C a
Moment = 0.5  V2 C2 d; d = 0
Dept of Aerospace Engineering, IIT-B
12/6/2018

7. Dept of Aerospace Engineering, IIT-B
Lift & Drag V 
Lift
Drag
Moment
(Pitching)
- Angle of Attack
Lift = 0.5  V2 C a
Moment = 0.5  V2 C2 d; d > 0
Dept of Aerospace Engineering, IIT-B
12/6/2018

8. Dept of Aerospace Engineering, IIT-B
Lift & Drag
Lift 
Moment
(Pitching)
Drag V
- Angle of Attack
Lift = 0.5  V2 C a
Moment = 0.5  V2 C2 d; d < 0
Dept of Aerospace Engineering, IIT-B
12/6/2018

9. Airfoil Moment is about = 0.25C Moment does not change with 
Symmetric
M = 0
Cambered
h > 0
M < 0
h < 0
M > 0
Moment does not change with 
Lift increases with 
Dept of Aerospace Engineering, IIT-B
12/6/2018

10. Airfoil Moment is about = 0.25C Moment does not change with 
Symmetric
M = 0
Cambered
h > 0
M < 0
h < 0
M > 0
Moment does not change with 
Lift increases with 
Dept of Aerospace Engineering, IIT-B
12/6/2018

11. Equilibrium & StabilityV L M V W L
Stable W L V L M W
Unstable
Dept of Aerospace Engineering, IIT-B
12/6/2018

12. Aerodynamic Center Point about which Moment does not change with 
0.25 C for an Airfoil
Stable
Unstable
Dept of Aerospace Engineering, IIT-B
12/6/2018

13. Airfoil, Flat Plate Or Strip of PaperW x
L = W
L * X + Mo = 0 ; X = - Mo/L
Camber M0
X for equilibrium
Stability because of X
Neutral
> 0
< 0
Unstable
Stable
Dept of Aerospace Engineering, IIT-B
12/6/2018

14. Airfoil, Flat Plate Or Strip of Paper
How to make a strip of paper fly?
AR is large  Like a flat plate airfoil
h = 0  M0 = 0  X = 0
X = 0  Neutral
For stability
h < 0  M0 > 0  X < 0
X < 0  Stable M0 L W
Dept of Aerospace Engineering, IIT-B
12/6/2018

15. Lets Fly a Strip of Paper!
Stable
CG without ballast
Dept of Aerospace Engineering, IIT-B
12/6/2018

16. Lets Fly a Strip of Paper!
Stable
CG with ballast
Dept of Aerospace Engineering, IIT-B
12/6/2018

17. Lets Fly a Strip of Paper!
Stable
Hinge line of elevator
Dept of Aerospace Engineering, IIT-B
12/6/2018

18. Dept of Aerospace Engineering, IIT-B
Wing Cr
Cr - Root chord
Aerodynamic Center Ct
Ct - Tip chord
 = Ct / Cr = Taper ratio
Dept of Aerospace Engineering, IIT-B
12/6/2018

19. Dept of Aerospace Engineering, IIT-B
Wing
Stable
Unstable
Aerodynamic Center
Dept of Aerospace Engineering, IIT-B
12/6/2018

20. Dept of Aerospace Engineering, IIT-B
Wing
Stable
Unstable
Aerodynamic Center
Dept of Aerospace Engineering, IIT-B
12/6/2018

21. Dept of Aerospace Engineering, IIT-B
Lets Fly a Wing!
Dept of Aerospace Engineering, IIT-B
12/6/2018

22. Wing + Horizontal Tail (No Fuselage)
acw Sw lT ST
acT
X = 0.8 * ST lT/Sw
Stable
Unstable x
Dept of Aerospace Engineering, IIT-B
12/6/2018

23. Dept of Aerospace Engineering, IIT-B
Vertical Tail? ?
Dept of Aerospace Engineering, IIT-B
12/6/2018

24. Vertical Tail? Dihedral?
Let’s move on
Dept of Aerospace Engineering, IIT-B
12/6/2018

25. Dept of Aerospace Engineering, IIT-B
Control Surfaces
Elevators
Ailerons
-             Control Surfaces
-             Elevator for pitch
-             Aileron for roll
-             Rudder for yaw
Rudder
Dept of Aerospace Engineering, IIT-B
12/6/2018

26. Dept of Aerospace Engineering, IIT-B
Elevators - Pitch
Dept of Aerospace Engineering, IIT-B
12/6/2018

27. Dept of Aerospace Engineering, IIT-B
Ailerons - Roll
Dept of Aerospace Engineering, IIT-B
12/6/2018

28. Dept of Aerospace Engineering, IIT-B
Rudder - Yaw
Dept of Aerospace Engineering, IIT-B
12/6/2018

29. 100 Years! How Small Has it got?
Dept of Aerospace Engineering, IIT-B
12/6/2018

30. Dept of Aerospace Engineering, IIT-B
Over the years!
How big can an aircraft get?
Mini
( 15 cm to 200 cm)
Micro
(< 15 cm)
How small can an aircraft get?
Dept of Aerospace Engineering, IIT-B
12/6/2018

31. Dept of Aerospace Engineering, IIT-B
Why Small Aircraft?
Surveillance
Hazard mitigation
Military applications
Dept of Aerospace Engineering, IIT-B
12/6/2018

32. Videography Platform - IITB
Components
Analysis? Assessment?
Toughest Challenge!
Video Transmitter
Range = 1000 m
Weight = 10 gm
Colour Video Camera
Weight = 9.5 gm
Size = 60 cm,
Weight = 870 gm
Dept of Aerospace Engineering, IIT-B
12/6/2018

33. Comparison 6” (1/4th in size) 24” But many folds more complex
Dept of Aerospace Engineering, IIT-B
12/6/2018

34. Dept of Aerospace Engineering, IIT-B
Early Attempts to Fly
Leonardo da Vinci
No success in imitating birds
Lord Cayley shows the way
Highly integrated solutions difficult!
Decompose and conquer
Dept of Aerospace Engineering, IIT-B
12/6/2018

35. Dept of Aerospace Engineering, IIT-B
Man Made Bird !
Flapping Flight Efficiencies have been low!
Dept of Aerospace Engineering, IIT-B
12/6/2018

36. Flapping Flight in India
“To the sheer amazement of the audience, the model began beating its wings just like a bird and started flying!”, AVIA August 2003
on Mr K Nandakumar, Chennai
Dept of Aerospace Engineering, IIT-B
12/6/2018

37. Fixed, Flapping, Rotary Wing?
Nature suggests flapping for small aerial vehicles
Efficiency of flapping wing vehicles built by man not very high!
Terrestrial Locomotion?
Nature suggests bi-peds/quadru-peds
Man made vehicles are wheeled
Multi-pedes, bi-peds !?
Dept of Aerospace Engineering, IIT-B
12/6/2018

38. Dept of Aerospace Engineering, IIT-B
Which Way!
MAV
Micro Electro-Mechanical Systems
Bio-mimetics
Bio-Optics
Optical Flow
Multi-function parts
Learning
Training
Genetic Modification
MAV
Dept of Aerospace Engineering, IIT-B
12/6/2018

39. Dept of Aerospace Engineering, IIT-B
Thank You
Dept of Aerospace Engineering, IIT-B
12/6/2018