1. Dynamics N Controls 1 PDR
Aether Aerospace
AAE 451
September 27, 2006
Mark Davis Ashley Gordon
Hank Kneitz Ryan Mulligan
Joshua Rodewald Brandon Wampler
Mathieu Hautier Samantha Pearcy

2. Overview Class 1 sizing of tail Class 1 sizing of control surfaces
Surface deflection limits
Location of ac
Location of cg
Determination of static margin
Class 2 sizing of tail
Determination of dihedral angle
July 3, 2019
AAE 451, Aether Aerospace

3. Class 1 Sizing of Tail The Angry Mosquito
Sized for a conventional tail
Matched surface area for conventional to V-design
Used reference data to approximate volume coefficients
Sv=1.1 ft2 total
July 3, 2019
AAE 451, Aether Aerospace

4. Class 1 Sizing of Control Surfaces
Sized for conventional tail
Used reference data to approximate control surface area relative to tail area
Used data for single propeller planes
Converted from conventional to V
Control surface area is the same as conventional tail with dihedral shown below
July 3, 2019
AAE 451, Aether Aerospace

5. Class 1 Sizing of Control SurfacesSa
0.26 ft2 Sr
0.078 ft2 Se
0.033 ft2
Sv-control
0.11 ft2
July 3, 2019
AAE 451, Aether Aerospace

6. Surface Deflection Limits
Servo limitation
Most servos are limited to ± 40° deflection
Trim diagram will reveal more
Power limitations
Large deflections at high speeds require more torque
May take power away from propulsion
Aerodynamic properties
Control Surface Stall Considerations
July 3, 2019
AAE 451, Aether Aerospace

7. Determination of Dihedral Angle
Effects
Contributes to lateral stability
Too much can cause Dutch Roll behavior
Unclear selection method thus far
McCombs: 0° - 2°
Lennon: 4°
Raymer: “no simple technique” → iterative
Temporary selection 4°
Conservative to maintain uncontrolled lateral stability
Better estimate when control is analyzed
July 3, 2019
AAE 451, Aether Aerospace

8. Location of Aerodynamic Center
Wing and Tail Contribution
Located at quarter cord
1% error
Fuselage Contribution
Considered negligible until further analysis
Initial Location
1.6 ft from nose
Calculated a.c.
.5c ft from LE
1.84 ft from nose
July 3, 2019
AAE 451, Aether Aerospace

9. Location of Center of Gravity
Important for static margin
Initial guess
Based on CATIA model with weight as far forward as possible
0.855 ft from nose, quite overzealous (seen in X-plots)
Desired value
.35c ft from LE
1.69 ft from nose
July 3, 2019
AAE 451, Aether Aerospace

10. Determination of Static Margin
5% - 10% Raymer
~15% Roskam
Desired value: SM=0.15
July 3, 2019
AAE 451, Aether Aerospace

11. Class 2 Sizing of Horizontal and Vertical Tail using X-Plots
C.G. does not allow for solution
Vertical Tail area = 0.7 ft2
July 3, 2019
AAE 451, Aether Aerospace

12. Move the C.G. back Move batteries back as a ballast
CG shift of 0.85 ft
15% SM with a horizontal tail area of 0.9 ft2
July 3, 2019
AAE 451, Aether Aerospace

13. Trim Diagram
July 3, 2019
AAE 451, Aether Aerospace

14. The Angry Mosquito
July 3, 2019
AAE 451, Aether Aerospace