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Gliders in Flight

Stability

for

Straight and Level Flights

GlidersLong Distance Fliers

Gaining Altitude

Balsa Glider?

Straight and Level = Maximum Distance

3 axis movement

Movement in Yaw

Movement in Roll

Movement in Pitch

Static Stability

Dynamic Stability

Lateral Stability:Roll

High wing aircraft are naturally stabilizing.

Lateral Stability:Roll

Low wing aircraft are naturally stabilizing.

Lateral Stability:Dihedral

Why does dihedral work?

Why does dihedral work?

Weight

Uniform Lift

Why does dihedral work?

Weight

Component of WeightCausing a Sideslip

Why does dihedral work?

Induced Relative Wind

Higher AOA

Lower AOAHigher Lift

Lower LiftRollingMoment

Lateral Stability:Types of Dihedral

No Dihedral

Straight Dihedral

Tip Dihedral

Polyhedral

Movement in Yaw

Directional Stability:Keel Effect

Directional Stability:Weather Vaning

Directional StabilityMoment Arms

Directional Stability

Movement in Pitch

Avoiding the Stalling

Weight and Balance

Center of Lift

Weight at Center of Gravity

Balanced, but easy to shift…

VERY nose heavy!

VERY tail heavy!

Center of Gravity Range

Questions?