Design

1
Design

• Chapter 8
• First Half

2
Design Requirements and Specifications

• Payload
• Range
• Cruising Speed
• Takeoff Landing Distance
• Ceiling

3
Economic Requirements

• Cost
• Fuel Consumption
• Maintainability
• Reliability

4
Airworthiness Requirements

• Design must meet FAA standards for safety
• FAA is responsible for safety of all civil
  aircraft
• Federal Air Regulations Part 23
• Light Planes 12,500 lbs or less
• Federal Air Regulations Part 25
• Airworthiness Standards Transport Category
  Airplanes

5
Design Phase

• Conceptual Design
• General concept of what the plane will look like
• Jet/prop, single/multi, high wing/low wing, fixed
  gear/retractable gear
• Preliminary Design
• The aerodynamic design, consideration of
  aerodynamics in arriving at overall configuration

6
Design Phase

• Detail Design
• The final stage
• Design of supporting structure
• Modification to preliminary desugn decisions

7
Initial Conception

• Step one Study the design specifications
• Step two Determine what characteristics to shoot
  for in payload, speed, range, takeoff distance,
  landing distance, climb rate, ceiling.

8
Terms

• Wing loading
• the ratio of weight to wing area
• the average weight that each unit of wing area
  must carry
• W/S
• Power loading
• the amount of power per unit of weight
• P/W

9
Fuselage Design

• The fuselage design shape for aerodynamic
  efficiency (low drag)
• Optimum shape for a typical four-place light
  plane is a fuselage length of approx. 24 feet
  with a diameter of 8 feet
• Figure 8-1 p. 217
• Figure 8-2 p. 218, figure 8-3, 8-4

10
Fuselage Design

• Tandem/ Side by side
• Seat pitch
• Aerodynamic stand point
• Cabin Height

11
Wing Design

• High/ Low configuration
• High Wing
• better L/D ratio, lateral stability, shorter
  landing distance, better crash fire protection
• Low Wing
• better landing gear support, roll
  maneuverability, easier refueling, shorter
  takeoff distance, crash energy absorption

12
Planform Selection

• Planform
• figure 8-7 combination of rectangular tapered
  wing planform
• Optimum airfoil
• low drag coefficient, min. drag at design lift
  coefficient, max. lift coefficient, pitching
  moment coefficient, sufficient thichness for
  spar, fuel, landing gear

13
Increased Thickness

• Increases maximum lift coefficient
• Increase drag coefficient
• Provides greater space for structure and fuel

14
Increased Camber

• Increases design lift coefficient
• Increases pitching moment
• Increases lift coefficient

15
Power Plant Selection

• Power to weight to ratio
• actual engine dimensions
• location of the carburetor
• best choice of prop
• cowling design

16
Quiz on Chapter 8
17
Quiz on chapter 8

• List and explain two design obstacles to study
  when designing a plane.