Lecture 9 (after 5) - Static Directional and Lateral Stability. Manoeuvre Stability. Flashcards
(14 cards)
What is static directional stability?
Ability of a/c to align itself with relative wind, so that wind moves equally on both sides.
Ability of a/c to resist slipping after yaw disturbance.
Condition for static directionally stable aircraft?
Dihedral vs anhedral?
Dihedral: stability
Anhedral: manoeuvrability
What is static lateral (roll) stability characterised with respect to?
Sideslip angle
Requirements for static lateral (roll) stability?
What is Cl and β WRT roll stability?
Cl = rolling moment coefficient
β = sideslip angle
3 pros of swept wing
- Lateral stability
- Less turbulence when speed changes
- Allows travelling at high speeds
What is manoeuvring flight?
Change from one state of flight to another, including in a/c accel.
Load factor equation
nz = 1/cosΦ
Condition for longitudinal manoeuvre stability?
Where are manoeuvring points on the wing?
Behind NP
What is a manoeuvre point?
The manoeuvre point is the center of pressure location on the wing at which the aircraft is in static equilibrium during manoeuvring.
Are manoeuvre points fixed?
No, move with load factor changes
Relative position of stick-free NP, stick-free MP, stick-fixed NP, stick-fixed MP?
