1. Structures Overview Material Properties Structures Construction
Landing Gear
Center of Gravity
Weight and Cost Estimation
V-n Diagram
Wing Loading Analysis
March 24, 2005

2. Material Properties Density (lbf/ft3) Young’s Modulus (ksi)
Yield Stress (psi)
Balsa 11
625
1725
Spruce 34
1500
8600
EPS Foam
1.5
72.5
EPP Foam
1.3
1000
4000
Epoxy
lb/ft2
500
14500
Ultrakote
lb/ft2
N/A
Values from Fall ’04 AAE 451 projects and
March 24, 2005

3. Wing Structure
March 24, 2005

4. Fuselage Structure Formers Stringers
Outer Fuselage (each): Six - 1” radius
Main Fuselage: Four - 2” radius One - 1” radius
Stringers
Outer Fuselage (each): Seven – 1/8” x 1/8” x 36” One – 1/8” x 1/2” x 36” (for landing gear mounts)
Main Fuselage: Eight – 1/8” x 1/8” x 20”
Balsa sticks
March 24, 2005

5. Tail Structure
March 24, 2005

6. Construction
March 24, 2005

7. Landing Gear Wire mounting Interchangeable
Rigid
Lightweight
Inexpensive
Easy to construct
Interchangeable
Smooth takeoff and landing on AstroTurf®
Pictures courtesy of
March 24, 2005

8. Gear Configuration Location Configuration Front gear by canard
Back gear by wing
Configuration
Wire strut attached to spar in outer fuselage with mounting bracket
Interchangeable with wheels, skis, and floats attached to mounting blocks
Fuselage Attachment
Wheel/Ski/Float Attachment
Pictures courtesy of
March 24, 2005

9. Center of Gravity Xcg = 1.708 ft Xnp = 1.856 ft Static Margin = 14.8%
March 24, 2005

10. Weight Estimation
March 24, 2005

11. Cost Estimation
March 24, 2005

12. V-n Diagram Level Flight Turning Flight Max Load Factor
Vdive ~ 50% higher than Vcruise
nmax= g @ Vloiter = 25 ft/sec
Typical limit load factors for general aviation (npositive = 3.0-g, nnegative = -1.5-g)
from Raymer, Daniel P., Aircraft Design: A Conceptual Approach p.407
March 24, 2005

13. Wing Loading Analysis
March 24, 2005