aircraft design

1. PRELIMINARY DESIGN OF A REGIONAL
PASSINGER AIRCRAFT
Team:
G.S.MAHARSHI 11521A2111
B.SRIKANTH 11521A2103
Y.V.KRISHNA REDDY 11521A2123

2. COMMERCIAL TRANSPORT JETs: REGIONAL CLASS
The regional transport airplanes are currently in considerable demand and many airplane companies are engaged in their
design. These airplanes could be propelled by a turbo-prop engine or a turbofan engine. The later would, have a shorter duration
of flight. However, a turboprop engined airplane is more economical than the turbofan powered airplane as the range is short
and payload is considerble lower than that of large commercial jets.
The examples of such airplanes are:ATR-72-200,ATR-72-500, De Havilland Dash 8- Q300,AIRBUS
A320,EMBRAER 190/95 etc…
Fig: Regional Jet Aircraft Powered by Turboprop
Engines

3. Aircraft design approach:
The design of an aircraft starts with a innovative idea or some set of requirments.The aircraft design process
has split-up as
Requirments(or)idea
Conceptual design
Preliminary design
Detail design
• Estimate aircraft maximum take-off weight
• Determine wing area and engine thrust (or power)
• approximate three-view of the aircraft that
represents the aircraft configuration
• Finely detailed aircraft design

4. MAIN STRUCTURAL COMPONENTS OF AN FIXED WING AIRCRAFT:
 Wing
 Fuselage
 Empennage
Fig:wings
Fig:fuselage
Fig:empennage

5. WING:
The wing may be considered as the most important component of an aircraft, since a fixed-wing aircraft is not able to fly
without it.The wing geometry and its features will influencing all other aircraft components. The primary function of the wing is
to generate sufficient lift force or simply lift (L) while generate minimum drag, and minimum pitching moment. These design
goals must be collectively satisfied throughout all flight operations
Figure:Aerodynamic characteristics of a wing
(a) Cl vs α (b) Cl vs Cd (c) Cmc/4 vs α

6. During the wing design process, eighteen parameters must be determined. They are as
follows:
 Wing reference (or planform) area (SW or Sref or S)
 Number of the wings
 Vertical position relative to the fuselage (high, mid, or low wing)
 Horizontal position relative to the fuselage
 Cross section (or airfoil)
 Aspect ratio (AR)
 Taper ratio
 Tip chord (Ct)
 Root chord (Cr)
 Mean Aerodynamic Chord (MAC or C)
 Span (b)
 Twist angle (or washout)
 Sweep angle
 Dihedral angle
 Incidence (iw)
 High lifting devices such as flap
 Aileron
 Other aspects

7. Fuselage:
The primary purpose of the fuselage is to house the payload. In transport airplanes the payload includes the passangers,
their luggage and cargo. In military airplanes it is the ammunition and /or special equipment. In addition to the payload, the
fuselageaccommodatesFuel,landing gear,Systems like airconditioning,hydraulic,electrical,pneumatic,electronic,emergency
oxygen, pressurization and auxilliary power unit.
Requirements:
STRUCTURAL:
•Skin carries cabin pressure (tension) and shear loads
•Longitudinal stringers carry the longitudinal tension and compression loads
•Circumferential frames maintain the fuselage shape and redistribute loads into the skin, and bulkheads carry
concentrated loads.
MATERIAL:
•Strength, Young's modulus, fatigue initiation, fatigue crack growth, fracture toughness and corrosion are all
important, but fracturetoughness is often the limiting design consideration.

8. Fig:Typical Segments of a Passenger Airplane
Fuselage

9. Figure:Fuselage And Its Structural Components Of An Aircraft

10. Empennage:
The empennage, commonly called the tail assembly of the airplane. Its main purpose is to give stability to the aircraft. The
tail in a conventional aircraft has often two components horizontal tail and vertical tail and carries two primary functions:
1. Trim (longitudinal and directional)
2. Stability (longitudinal and directional)
Since two conventional control surfaces (i.e. elevator and rudder) are indeed parts of the tails to implement control, it is proper
to add the following item as the third function of tails:
3. Control (longitudinal and directional)
In general, tail is designed based on the trim requirements, but later revised based on stability
and control requirements.

11. The following are the tail parameters which need to be
determined during the design process:
1. Tail configuration
2. Horizontal tail horizontal location with respect to
fuselage (aft tail or canard)
Horizontal tail
3. Planform area (Sh)
4. Tail arm (lh)
5. Airfoil section
6. Aspect ratio (ARh)
7. Taper ratio ( h)
8. Tip chord (Ch_tip)
9. Root chord (Ch_root)
10. Mean Aerodynamic Chord (MACh or Ch)
11. Span (bh)
12. Sweep angle (ht)
13. Dihedral angle (ht)
14. Tail installation
15. Incidence (ih)
Vertical tail
16. Planform area (Sv)
17. Tail arm (lv)
18. Airfoil section
19. Aspect ratio (ARv)
20. Taper ratio ( v)
21. Tip chord (Ct_v)
22. Root chord (Cr_v)
23. Mean Aerodynamic Chord (MACv or Cv)
24. Span (bv)
25. Sweep angle ( v)
26. Dihedral angle ( v)
27. Incidence (iv)

12. Figure:Empennage of an airplane

14. THANK
YOU