STABILITY AND CONTROL – Air – DGCA Question Bank For Politics

#1. An aeroplane which is inherently stable will:

require less effort to control

be difficult to stall

not spin

have a built-in tendency to return to its original state following the removal of any disturbing force

#2. After a disturbance in pitch an aircraft oscillates in pitch with increasing amplitude. It is:

statically and dynamically unstable

statically stable but dynamically unstable

statically unstable but dynamically stable

statically and dynamically stable

#3. Longitudinal stability is given by:

the fin

the wing dihedral

the horizontal tailplane

the ailerons

#4. An aircraft is constructed with dihedral to provide:

lateral stability about the longitudinal axis

longitudinal stability about the lateral axis

lateral stability about the normal axis

directional stability about the normal axis

#5. Lateral stability is reduced by increasing:

Anhedral

Dihedral

Sweepback

Fuselage and fin area

#6. If the wing AC is forward of the CG:

changes in lift produce a wing pitching moment which acts to reduce the change of lift

changes in lift produce a wing pitching moment which acts to increase the change of lift

changes in lift give no change in wing pitching moment

when the aircraft sideslips the CG causes the nose to turn into the sideslip thus applying a restoring moment

#7. The longitudinal static stability of an aircraft:

is reduced by the effects of wing downwash.

is increased by the effects of wing downwash.

is not affected by wing downwash

is reduced for nose up displacements, but increased for nose down displacements by the effects of wing downwash

#8. To ensure some degree of longitudinal stability in flight, the position of the CG:

must always coincide with the AC

must be forward of the Neutral Point

must be aft of the Neutral point

must not be forward of the aft CG limit

#9. When the CG is close to the forward limit:

very small forces are required on the control column to produce pitch

longitudinal stability is reduced.

very high stick forces are required to pitch because the aircraft is very stable

stick forces are the same as for an aft CG

#10. The static margin is equal to the distance between:

the CG and the AC

the AC and the neutral point

the CG and the neutral point

the CG and the CG datum point

#11. If a disturbing force causes the aircraft to roll:

wing dihedral will cause a rolling moment which reduces the sideslip

the fin will cause a rolling moment which reduces the sideslip.

dihedral will cause a yawing moment which reduces the sideslip

dihedral will cause a nose up pitching moment

#12. With flaps lowered, lateral stability:

will be increased because of the effective increased of dihedral

will be increased because of increased fit

will be reduced because the centre of lift of each semi-span is closer to the wing root.

will not be affected

#13. Dihedral gives a stabilising rolling moment by causing an increase in lift:

on the up going wing when the aircraft rolls

on the down going wing when the aircraft rolls

on the lower wing if the aircraft is sideslipping

on the lower wing whenever the aircraft is in a banked attitude.

#14. A high wing configuration with no dihedral, compared to a low wing configuration with no dihedral, will provide:

greater longitudinal stability

the same degree of longitudinal stability as any other configuration because dihedral gives longitudinal stability

less lateral stability than a low wing configuration

greater lateral stability due to the airflow pattern around the fuselage when the aircraft is sideslipping increasing the effective angle of attack of the lower wing.

#15. At a constant IAS, what affect will increasing altitude have a damping in roll:

remains the same

increases because the TAS increases

decreases because the ailerons are less effective

decreases because the density decreases.

#16. Sweepback of the wings will:

not affect lateral stability

decreases lateral stability

increases lateral stability at high speeds only

increases lateral stability at all speeds

#17. At low forward speed:

increased downwash from the wing will cause the elevators to be more responsive

due to the increased angle of attack of the wing the air will flow faster over the wing giving improved aileron control

a large sideslip angle could cause the fin to stall

a swept back wing will give an increased degree of longitudinal stability

#18. Following a lateral disturbance, an aircraft with Dutch roll instability will:

go into a spiral dive

develop simultaneous oscillations in roll and yaw

develop oscillations in pitch

develop an unchecked roll

#19. To correct dutch roll on an aircraft with no automatic protection system:

use roll inputs

use yaw inputs

move the CG

reduce the speed below M MO

#20. A yaw damper:

increase rudder effectiveness:

must be disengaged before making a turn.

augments stability

increase the rate of yaw

#21. A wing which is inclined downwards from root to tip is said to have:

wash out

taper

sweep

anhedral

#22. The lateral axis of an aircraft is a line which:

passes through the wing tips

passes through the centre of pressure, at right angles to the direction of the airflow

passes through the quarter chord point of the wing root, at right angles to the longitudinal axis

passes through the centre of gravity, parallel to a line through the wing tips.

#23. Loading an aircraft so that the CG exceeds the aft limits could result in:

loss of longitudinal stability, and the nose to pitch up at slow speeds

excessive upwards force on the tail, and the nose to pitch down

excessive load factor in turns

high stick forces

#24. The tendency of an aircraft to suffer from dutch roll instability can be reduced:

by sweeping the wings

by giving the wings anhedral

by reducing the size of the fin

by longitudinal dihedral

#25. What determines the longitudinal static stability of an aeroplane?

The relationship of thrust and lift to weight and drag

The effectiveness of the horizontal stabilizer, rudder, and rudder trim tab

The location of the CG with respect to the AC

the size of the pitching moment which can be generated by the elevator

#26. Dihedral angle is:

the angle between the main plan and longitudinal axis

the angle measured between the main plane and the normal axis

the angle between the quarter chord line and the horizontal datum

the upward and outward inclination of the main places to the horizontal datum

#27. Stability around the normal axis:

is increased is the keel surface behind the CG is increased

is given by the lateral dihedral

depends on the longitudinal dihedral

is greater if the wing has no sweepback

#28. The centre of Gravity of an aircraft is found to be within limits for take-off:

the C of G will be within limits for landing

the C of G for landing must be checked, allowing for fuel consumed

the C of G will not change during the flight

the flight crew can adjust the CG during flight to keep it when acceptable limits for landing

#29. The ailerons are deployed and returned to neutral when the aircraft has attained a small angle of bank. If the aircraft then returns to a wings-level attitude without further control movement it is:

neutrally stable

statically and dynamically stable

statically stable, dynamically neutral

statically stable

#30. The property which tends to decreases rate of displacement about any axis, but only while displacement is taking place, is known as:

stability

controllability

aerodynamic damping

manoeuverability

#31. If an aircraft is loaded such that the stick force required to change the speed is zero

the CG is on the neutral point

the CG is behind the neutral point

the CG is on the manouevre point

the CG is on the forward CG limit

Dgca Question Bank For Pilots

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