8.4 Flight Stability And Dynamics Flashcards
Three axis working on a plane
Longitudinal axis
Lateral axis
Vertical axis
Pitch works on what axis?
Lateral axis
Yaw works on what axis?
Vertical axis
Roll works on what axis?
Longitudinal axis
Stability affects what two areas?
Manoeuvrability
Controllability
What is static stability?
The initial tendency of an aircraft to return back to its position of equilibrium
Three types of static stability?
Positive static stability
Neutral static stability
Negative static stability
What is positive static stability?
An aircraft that has positive static stability has the tendency to return to the original state of equilibrium after being disturbed.
What is neutral static stability?
An aircraft that has neutral static stability tends to stay in its new attitude when it’s disturbed
What is negative static stability?
An aircraft that has negative static stability tends to continue moving away from its original attitude when it’s disturbed
What is longitudinal stability?
the tendency for the nose to pitch up or pitch down, rotating around the lateral axis.
When gust hits upper part of aircraft surface what happens?
Nose down rotation
When gust hits lower part of aircraft surface what happens
Nose up rotation
Directional stability is around what axis?
Vertical axis
The movement of directional stability is what?
Yaw
Directional stability is also known as what?
Weathercock stability
What improves directional stability?
Sweep back of a wing
Dorsal fin
Keel surface
Lateral stability is on what axis?
Longitudinal axis
Four main design factors to keep aircraft laterally stable?
Dihedral
Sweep back
Keel effect
Weight distribution
What is the side slip angle?
The sideslip angle is the angle between the aircraft centreline and the sideslip direction.
Dutch roll exists when?
Dutch roll exists when there is a greater effect on the lateral stability than on the directional stability.
