Stabilty Flashcards
What is stability?
Small aerodynamic forces (restoring moments) automatically turn the aircraft equilibrium after each small upset
What is static Stability
Describes the immediate response of an object when it displace from equilibrium
Positive Static Stability
Initial tendency to equalibrium position
Natural Static Stability
No tendency to move to initial position
Negative Static Stability
Initial endecy from equilibrium position
Controllability
The higher stability, the harder it is to displace the aircraft.
Dynamic stability
The subsequent response of an object over a period of time, after it has been displaced from equilibrium by a disturbing force and after the disturbing force has been removed
Damped phugoid, also called periodic motion
For Symetrical section (e.g. tailplane)
AC coccurs at approx. 25% chord
Cambered aerofoil (subsonic))
AC tends to lie at a fixed point in a range of 23% to 27% of the chord, depending of the cross.sectional shape of the aerofoil
The horizontal stabiliser contributes what?
static stability
Yaw Moment coefficient formula
Cn = q s b
