POF Q30 - Directional and Lateral Stability Flashcards
An aeroplane has static directional stability; in a side-slip to the right, initially the:
Select one:
a.nose of the aeroplane tends to move to the left.
b.nose of the aeroplane will remain in the same direction.
c.nose of the aeroplane tends to move to the right.
d.right wing tends to go down.
c.nose of the aeroplane tends to move to the right.
Static directional stability is the:
Select one:
a.initial tendency of an aeroplane to return to straight flight after a disturbance in yaw.
b.initial tendency of an aeroplane to raise the low wing in a sideslip.
c.natural ability of an aeroplane to recover from a disturbance about the longitudinal axis.
d.initial tendency of an aeroplane to recover from a disturbance about the lateral axis.
a.initial tendency of an aeroplane to return to straight flight after a disturbance in yaw.
An aeroplane’s sideslip angle is defined as the angle between the:
Select one:
a.longitudinal axis and relative airflow
b.lateral axis and the horizontal plane.
c.speed vector and the horizontal plane.
d.relative airflow and normal axis.
a.longitudinal axis and relative airflow
Which of the following provides a positive contribution to static directional stability?
PICK ALL CORRECT ANSWERS
Select one or more:
a.A forward swept wing.
b.A dorsal fin.
c.Strakes
d.A low wing as compared with a high wing.
e.Moving the centre of gravity aft.
f.Ventral fin
b.A dorsal fin.
c.Strakes
f.Ventral fin
Increasing the size of the fin:
Select one:
a.reduces lateral stability.
b.increases the directional stability.
c.reduces directional stability.
d.increases lateral stability and directional control.
b.increases the directional stability.
Sweepback of a wing positively influences: 1) Static longitudinal stability, 2) Static lateral stability, 3) Dynamic longitudinal stability. The combination that regroups all of the correct statements is:
Select one:
a.2
b.1, 2, 3
c.1
d.3
a.2
An aeroplane has static directional stability. In a side-slip to the right, initially the:
Select one:
a.nose of the aeroplane will remain in the same direction.
b.right wing tends to go down.
c.nose of the aeroplane tends to move to the right.
d.nose of the aeroplane tends to move to the left.
c.nose of the aeroplane tends to move to the right.
Which of the following statements is correct?
1) A dorsal fin increases the contribution of the vertical tail plane to the static directional stability, in particular at large angles of sideslip.
2) A dorsal and a ventral fin both have a positive effect on static lateral stability.
Select one:
a.1) is incorrect, 2) is correct.
b.1) is correct, 2) is correct.
c.1) is correct, 2) is incorrect.
d.1) is incorrect, 2) is incorrect.
c.1) is correct, 2) is incorrect.
Directional stability is the stability around the:
Select one:
a.lateral axis.
b.longitudinal axis.
c.normal axis.
d.pitch axis.
c.normal axis.
The effect on lateral static stability of an aeroplane with a high wing as compared to a low wing is:
Select one:
a.a positive dihedral effect
b.zero dihedral effect
c.a negative dihedral effect
d.no effect as it is only used to improve aeroplane loading
a.a positive dihedral effect
Static lateral stability will be decreased by:
Select one:
a.reducing wing anhedral.
b.the use of a low, rather than high, wing mounting.
c.increasing the size of the vertical tail.
d.increasing wing sweepback.
b.the use of a low, rather than high, wing mounting.
Positive static lateral stability is the tendency of an aeroplane to:
Select one:
a.roll to the left in the case of a sideslip angle (with the aeroplane nose pointing to the right of the incoming flow).
b.roll to the left in a right turn.
c.roll to the right in a right turn.
d.roll to the left in the case of a sideslip (with the aeroplane nose pointing to the left of the incoming flow).
d.roll to the left in the case of a sideslip (with the aeroplane nose pointing to the left of the incoming flow).
With a swept wing aircraft, with an increase in altitude, which of the following statements about lateral stability is correct?
Select one:
a.Static lateral stability decreases, dynamic lateral stability increases.
b.Static lateral stability increases, dynamic lateral stability increases.
c.Static lateral stability increases, dynamic lateral stability decreases.
d.Static lateral stability remains the same, dynamic lateral stability decreases.
d.Static lateral stability remains the same, dynamic lateral stability decreases.
Which of the following lists contain aeroplane design features that all increase static lateral stability?
Select one:
a.Low wing, dihedral, elliptical wing planform.
b.Sweep back, under wing mounted engines, winglets.
c.Fuselage mounted engines, dihedral, T-tail.
d.High wing, sweep back, large and high vertical fin.
d.High wing, sweep back, large and high vertical fin.
Dihedral of the wing:
Select one:
a.decreases the static lateral stability.
b.is the only way to increase the static lateral stability.
c.increases the static lateral stability.
d.is only positive for aeroplanes with high mounted wings.
c.increases the static lateral stability.
