STABILITY AND MANOEUVRABILITY – Air – DGCA Question Bank For Politics

#1. What is short period mode?

Pilot induced oscillation.

Oscillation about the lateral axis.

Oscillation about the longitudinal axis.

Oscillation about the normal axis.

#2. What is phugoid motion?

Short period longitudinal oscillations.

Long period longitudinal oscillations.

Long period lateral oscillations.

Long period yawing oscillations.

#3. Where is the aft C of G limit of an aircraft?

Behind the neutral point.

Ahead of the neutral point.

On the neutral point.

On the manoeuvre point.

#4. At what position on an aircraft must the C of G be to make it neutrally longitudinally stable during pull up manoeuvres?

The transition point.

The neutral point.

The aerodynamic centre.

The manoeuvre point.

#5. Which of the following contribute to lateral stability?

Anhedral, sweepback, high wing, high fin.

Dihedral, sweepback, low wing, high fin.

Anhedral, aspect ratio, high wing, ventral fin.

Dihedral, sweepback, high wing, high fin.

#6. What purpose is served by a dorsal fin at high sideslip angles?

Decreases effectiveness of the fin in order to reduce lateral instability.

Increases effectiveness of the fin by increasing its area.

lncreases effectiveness of the fin by reducing its aspect ratio.

Decreases effectiveness of the fin in order to reduce Dutch roll.

#7. What action should be taken in order to prevent Dutch roll if the rudder damper system fails when flying at high sped at high altitude?

Reduce speed and altitude immediately.

Reduce altitude.

Reduce altitude then reduce speed.

Increase speed.

#8. What would be the effect of loading an aircraft such that its C of G was on the forward limit?

lncreased longitudinal, lateral and directional stability.

Decreased longitudinal, lateral and directional stability.

lncreased longitudinal and directional stability but no effect on lateral stability.

Increased longitudinal and lateral stability but no effect on directional stability.

#9. What is the relationship between stability and manoeuvrability?

In order to be manoeuvrable an aircraft must first be stable.

Manoeuvrability and stability are not connected in any way.

Depends on the design of the aircraft autopilot system.

Stability and manoeuvrability are inversely related.

#10. What is the effect of increasing wing sweep on the stability of an aircraft?

lncreased longitudinal, lateral and directional stability.

lncreased longitudinal and directional stability.

Increased lateral and directional stability

Increased longitudinal and lateral stability.

#11. What is the pitching moment generated by a cambered wing about its aerodynamic centre in flight?

Always nose up and of constant magnitude.

Always nose down and of varying magnitude with angle of attack.

Nose up or nose down depending on angle of attack.

Always nose down at its zero lift value.

#12. What effect does an increase in angle of attack have on the distance between the aerodynamic centre and centre of pressure of a wing in flight?

The distance remains constant.

The distance becomes greater.

The distance becomes smaller.

The distance becomes smaller up to the stall then becomes greater.

#13. Which of the following combinations of stability are acceptable in a JAR certificated commercial aircraft?

Statically unstable, dynamically stable.

Statically stable, dynamically unstable.

Dynamically and statically unstable.

Dynamically and statically stable.

#14. Which of the following conditions would maximise stability?

C of G on aft limit.

C of G on forward limit.

C of G on the manoeuvre point.

C of G on the neutral point.

#15. What is the position of the aft C of G limit in relation to the manoeuvre point of the aircraft?

Always behind the manoeuvre point.

Always ahead of the manoeuvre point.

Ahead or behind the manoeuvre point, depending on the fuel load.

Always directly above the manoeuvre point.

#16. Which of the following combinations contribute to lateral stability?

Anhedral, low wings, ventral fins, wing sweep back

Dihedral, high wings, dorsal fins, wing sweep back.

Anhedral, low wings, dorsal fins, straight wings.

Dihedral, high wings, ventral fins, low C of G.

#17. What is phugoid motion?

Weakly damped long period oscillations in pitch attitude, altitude and airspeed with approximately constant angle of attack.

Highly damped short period oscillations in pitch attitude, altitude and airspeed with approximately constant angle of attack.

Pilot induced long period oscillations in pitch attitude, altitude and airspeed with approximately constant angle of attack.

Not possible in swept wing aircraft.

#18. How will a change of C of G position affect the period of oscillations?

Forward movement of C of G will increases period.

Aft movement of C of G will increase period.

None of the above.

It depends on weight.

#19. What will be the effect of excessive directional stability?

Phugoid motion.

It will not be possible to yaw the aircraft.

Dutch roll.

Spiral instability.

#20. Which of the following are possible in an aircraft?

Statically unstable and dynamically stable.

Statically stable and dynamically stable.

Statically unstable and neutrally dynamically stable.

Neutrally statically table and positively dynamically stable.

#21. Which of the following conditions imposes the greatest stick force during landing?

C of G aft and flaps down.

C of G forward and flaps up.

C of G aft and flaps up.

C of G forward and flaps down.

#22. What would be the effect of forward movement of the C of G?

Lower stick force gradient.

Positive stick force gradient.

Negative stick force gradient.

Neutral stick force gradient.

#23. How would forward movement of C of G affect manoeuvre stability?

Increase.

Decrease.

Increases or decreases pending on weight.

None of the above.

#24. Which of the following would make stalling most likely in low speed flight?

Aft C of G.

Forward C of G.

No C of G.

Central C of G.

#25. Which of the following are true of an aircraft that is positively statically stable?

It is never dynamically stable.

It is always dynamically stable.

It might be dynamically stable.

It is always dynamically stable.

#26. What would be the effect of increasing camber?

CL would decrease.

Angle of attack would increase.

Longitudinal stability would be unaffected.

Lateral stability would be increased.

#27. How does anhedral affect stability?

Increases directional stability.

Decreases lateral stability.

Decreases longitudinal stability.

None of the above.

#28. An aircraft that is directionally statically unstable?

Will exhibits spiral instability.

Will be directionally dynamically stable.

Will yaw into sideslip.

Will yaw away from sideslip.

#29. What effect does roll damping have on stability?

Increases lateral dynamic stability.

Increases lateral static stability.

Increases frequency of oscillations.

Decreases frequency of oscillations.

#30. What effect do wing-mounted engine pods tend to have on stability?

Increase.

Decrease.

Increase or decrease depending on weight.

None of the above.

#31. Which of the following is essential for longitudinal stability?

A serviceable autopilot system.

A tailplane.

A canard.

Longitudinal dihedral.

#32. What effect does longitudinal dihedral have on a canard configuration?

Canard stalls after wing.

Canard stalls before wing.

Canard cannot stall.

Canard and wing stall together.

#33. What effect does longitudinal dihedral have on a tailplane configuration?

Tailplane stalls first.

Wing stalls first.

Tailplane cannot stall.

Wing and tailplane stall together.

#34. What is short period motion?

Low frequency oscillations.

High frequency oscillations about the lateral axis.

High magnitude oscillations about the lateral axis.

Rapid oscillations about the longitudinal axis.

#35. The aft C of G limit is?

Aft of the neutral point.

Forward of the neutral point.

Above the neutral point.

The neutral point.

#36. Wing sweep back?

Increases lateral and directional stability.

Increases longitudinal and directional stability.

Increases longitudinal and lateral stability.

None of the above.

#37. Wing sweep back?

Increases speed stability.

Decreases speed stability.

Decreases lateral stability.

None of the above.

#38. If an aircraft is longitudinally statically unstable?

It will be speed unstable.

It will be speed stable.

Longitudinal and speed stability are not related.

It will exhibit phugoid motion.

#39. What effect does increasing altitude have on stability?

Stability increases with altitude.

Stability decreases with altitude, all modes being affected to the same degree. Stability decreases with altitude, all modes being affected to the same degree.

Stability decreases with altitude all modes not being affected to the same degree.

Altitude has no effect on stability.

#40. If the yaw damper fails when flying at cruising speed at maximum altitude?

Descend to prevent Dutch roll.

Slow down to prevent Dutch roll.

Slow down then descend to prevent Dutch roll.

Descend then slow down to prevent Dutch roll.

#41. Spiral instability is likely when?

Directional stability is weaker than longitudinal stability.

Lateral stability is weaker than directional stability.

Lateral stability is stronger than directional stability.

The aircraft is directionally unstable.

#42. In phugoid motion?

Airspeed is constant.

Angle of attack is constant.

Attitude is constant.

Altitude is constant.

#43. What effect does CD have on phugoid characteristics?

High CD gives high tendency to phugoid.

Low CD gives high tendency to phugoid.

CD has no effect on phugoid.

None of the above.

#44. How can a pilot stop short period motion?

Use the controls.

Switch off the autopilot.

Release the controls.

Dive the aircraft.

#45. Constant amplitude oscillations about any axis are?

Dynamic instability.

Static instability.

Static stability plus neutral dynamic stability.

Neutral static stability plus positive dynamic stability.

#46. A ventral fin will?

Increase dynamic lateral stability.

Increase static lateral stability.

Decrease directional stability.

None of the above.

#47. A ventral fin will?

Increase directional stability in sideslip.

Decrease directional stability in sideslip.

Increase longitudinal stability in sideslip.

Be unaffected by sideslip.

#48. A ventral fin will?

Not affect Dutch Roll.

Reduce tendency to Dutch Roll.

Increase tendency to Dutch Roll.

Reduce tendency to spiral instability.

#49. Longitudinal stability requires?

A tailplane.

An autopilot.

An aft C of G.

Longitudinal dihedral.

#50. What effect does dihedral have on the stick force necessary to maintain sideslip?

Decreases it.

Increases it.

Increase or decrease depending on directional stability.

None of the above.

#51. Dutch Roll tendency is increased by?

Forward movement of C of G.

Aft movement of C of G.

Forward movement of C of P.

Aft movement of C of P.

#52. C of G on forward limit?

Increases VMCG.

Decreases VMCG.

Increases stick force.

Decreases stick force.

#53. What is short period mode?

Oscillation about the lateral axis.

Pilot induced.

Oscillation about the longitudinal axis.

Oscillation about the normal axis.

#54. Dutch Roll occurs when ........ stability is greater than .......... stability?

Lateral dynamic, Lateral static.

Lateral static, Lateral dynamic.

Lateral static, Directional.

Lateral dynamic, Longitudinal.

#55. Strong lateral dynamic stability will. .. . . ... Dutch Roll?

Increase.

Decrease.

Not affect.

Increase or decrease depending on directional stability.

#56. ......... increases manoeuvrability?

An aft C of P.

An aft C of G.

A High wing.

A High tailplane.

#57. Sweepback produces .......?

Strong longitudinal stability.

Strong lateral stability.

High roll rates.

High pitching rates.

#58. Sweepback produces?

Strong longitudinal stability.

Strong directional stability.

High yaw rates.

Low pitching rates.

#59. ............... increases manoeuvrability?

Dihedral.

Anhedral.

Low C of G.

Forward C of G.

#60. Dutch Roll is?

Stable cyclical rolling from one wing down to the other.

Unstable cyclical rolling from one wing down to the other.

Long period pitching with constant angle of attack.

Short period yawing with constant bank angle.

#61. Which of the following statements is true?

Positive yaw is nose to the left.

Positive yaw is nose to the right.

Positive sideslip is to the left.

Positive pitching is nose down.

#62. Which of the following statements is true?

The positive longitudinal axis is aft.

The positive lateral axis is left.

The positive lateral axis is right.

Positive roll is to the left.

#63. Which of the following is true?

Left yaw causes positive sideslip.

Left roll causes positive sideslip.

Positive sideslip causes positive bank.

Positive sideslip is to the left.

#64. Positive longitudinal stability requires a .............. CM:a slope?

Positive.

Negative.

Curved.

Flat

#65. Positive lateral stability requires a ............ Cl:B slope?

positive

Negative.

Curved.

Flat.

#66. Positive directional stability requires a .............. Cn:B slope?

positive

Negative.

Curved.

Flat.

#67. Stick free stability is ............ stick fixed stability?

Greater than.

Weaker than.

The same as.

Less important than.

#68. An in limits aft C of G will .......... stick force gradient?

Increase.

Decrease.

Not affect.

Increase or decrease depending on neutral point location.

#69. A dorsal fin ................ the effectiveness of the fin by ..............?

Increases, decreasing its aspect ratio.

Increases, increases its aspect ratio.

Decreases, decreasing aspect ratio.

Decreases, increasing aspect ratio.

#70. A fin with a dorsal fin will have a ........... CL:B slope and a ......... stalling angle compared to one without ?

Steeper, lower.

Steeper, higher.

Shallower, lower.

Shallower, higher.

#71. Increasing fin height will ........... static lateral stability and .......... dynamic lateral stability?

Increase, increase.

Increase, decrease.

Decrease, decrease.

Decrease, increase.

#72. Increasing fin height will ............ static directional stability and ......... dynamic directional stability?

Increase, increase.

Increase, decrease.

Decrease, decrease.

Decrease, increase.

#73. Adding a ventral fin will............ static lateral stability and .. ....... directional stability?

Increase, increase.

Increase, decrease.

Decrease, decrease.

Decrease, increase.

#74. Adding a dorsal fin will . . . . . . . . .. The tendency to spiral instability?

Increase.

Decrease.

Increase or decrease depending on size of dorsal fin.

Not affect.

#75. Adding a ventral fin will ...... tendency to Dutch Roll?

Increase.

Decrease.

Increase or decrease depending on size of dorsal fin.

Not affect.

#76. Longitudinal static stability requires a?

Negative CM,:B gradient.

Positive CM:B gradient

Negative CM:a gradient.

Positive CM:a gradient.

#77. Lateral static stability requires a?

Negative CI:B gradient.

Positive Cl:B gradient

Negative C1:a gradient.

Positive Cl:a gradient.

#78. Directional static stability requires a?

Negative Cn:B gradient.

Positive Cn:B gradient

Negative Cn:a gradient.

Positive Cn:a gradient.

#79. Directional stability requires that the aircraft generates a yawing moment that is ...............?

Directly proportional to yaw angle.

Negatively proportional to yaw angle.

Directly proportional to sideslip angle.

Negatively proportional to sideslip angle.

#80. Positive static longitudinal stability requires?

An aft C of G.

A low C of G.

A forward C of P.

Longitudinal dihedral.

#81. Positive static longitudinal stability requires?

A forward C of G.

A low C of G.

A forward C of P.

Longitudinal anhedral.

#82. A highly stable aircraft requires .............. to manoeuvre?

A low tailplane.

A high tailplane.

Fly-by wire controls.

High stick forces.

#83. Strong dynamic stability requires?

Weak aerodynamic damping.

Strong aerodynamic damping.

No aerodynamic damping.

Mass balancing of its control surfaces.

#84. Winglets?

Improve lateral and directional stability.

Reduce lateral and directional stability.

Do not significantly affect lateral and directional stability.

Improve roll rates.

#85. Deep stall is most likely in an aircraft with?

A canard.

A delta wing.

Straight wings.

Low aspect ratio wings.

#86. Single engine failure is more likely to cause rolling in a ..............aircraft than in a ...............?

Twin counter rotating propeller, twinjet.

Single jet, single propeller.

Contra-rotating propeller, twinjet.

Twin jet, twin propeller.

#87. Short period oscillation occurs around the ........... axis.

Longitudinal

Lateral

Normal

Pitch

#88. The yaw damper uses a .......... gyro to sense ........?

Vertical,roll rate.

Horizontal,roll range.

Vertical,Yaw displacenient.

Horizontal, yaw rate.

#89. The yaw damper prevents ........... by enhancing ............ stability?

Dutch roll, lateral.

Dutch roll, directional.

Spiral instability, lateral.

Spiral instability, directional.

#90. Directional stability is ............. by ..............?

Increased, high wings.

Increased, wing sweep back.

Decreased, high wings.

Decreased, wing sweep back.

#91. Lateral stability is...........by............?

Increased, increasing TAS.

Increased, increasing altitude.

Decreased, decreasing TAS.

Decreased, increasing altitude.

#92. Aerodynamic damping increases with increasing?

Altitude

TAS.

Aspect ratio.

Sweep back.

#93. Stick forces in a fly-by-wire system increase in proportion to?

Weight and C of G position.

Altitude and IAS.

Control deflection and IAS.

#94. Lateral static stability is increased by?

High fin, low C of G, low wings.

Low fin, high C of G, high wings.

Anhedral, low C of G, high wings.

Dihedral, sweep back,high wings.

#95. A C of G aft of the after limit will?

Reduces manoeuvrability about the lateral axis.

Reduce stability and trim drag in cruise flight.

Reduce stability and increase trim drag in cruise flight.

Increase stability and stalling speed.

#96. A forward C of G will?

Increase manoeuvrability about the lateral axis.

Improve stability and increase trim drag in cruise flight.

Reduce stability and increase trim drag in cruise flight.

Reduce stability and stalling speed.

#97. Roll damping ............ with roll rate?

Increases.

Decreases.

Increases or decreases depending on TAS.

Does not vary.

#98. A statically unstable aircraft ............ dynamically stable?

Is always.

Is never.

Is sometimes.

Does not need to be.

#99. The fuselage of an aircraft ............. its stability?

Tends to increase.

Tends to decrease.

Increases or decreases depending on TAS.

Has no effect on.

#100. Longitudinal dihedral?

Is essential for stability.

Is desirable for stability.

Has no effect on.

Is not possible in a canard configuration.

Dgca Question Bank For Pilots

Results

#1. What is short period mode?

#2. What is phugoid motion?

#3. Where is the aft C of G limit of an aircraft?

#4. At what position on an aircraft must the C of G be to make it neutrally longitudinally stable during pull up manoeuvres?

#5. Which of the following contribute to lateral stability?

#6. What purpose is served by a dorsal fin at high sideslip angles?

#7. What action should be taken in order to prevent Dutch roll if the rudder damper system fails when flying at high sped at high altitude?

#8. What would be the effect of loading an aircraft such that its C of G was on the forward limit?

#9. What is the relationship between stability and manoeuvrability?

#10. What is the effect of increasing wing sweep on the stability of an aircraft?

#11. What is the pitching moment generated by a cambered wing about its aerodynamic centre in flight?

#12. What effect does an increase in angle of attack have on the distance between the aerodynamic centre and centre of pressure of a wing in flight?

#13. Which of the following combinations of stability are acceptable in a JAR certificated commercial aircraft?

#14. Which of the following conditions would maximise stability?

#15. What is the position of the aft C of G limit in relation to the manoeuvre point of the aircraft?

#16. Which of the following combinations contribute to lateral stability?

#17. What is phugoid motion?

#18. How will a change of C of G position affect the period of oscillations?

#19. What will be the effect of excessive directional stability?

#20. Which of the following are possible in an aircraft?

#21. Which of the following conditions imposes the greatest stick force during landing?

#22. What would be the effect of forward movement of the C of G?

#23. How would forward movement of C of G affect manoeuvre stability?

#24. Which of the following would make stalling most likely in low speed flight?

#25. Which of the following are true of an aircraft that is positively statically stable?

#26. What would be the effect of increasing camber?

#27. How does anhedral affect stability?

#28. An aircraft that is directionally statically unstable?

#29. What effect does roll damping have on stability?

#30. What effect do wing-mounted engine pods tend to have on stability?

#31. Which of the following is essential for longitudinal stability?

#32. What effect does longitudinal dihedral have on a canard configuration?

#33. What effect does longitudinal dihedral have on a tailplane configuration?

#34. What is short period motion?

#35. The aft C of G limit is?

#36. Wing sweep back?

#37. Wing sweep back?

#38. If an aircraft is longitudinally statically unstable?

#39. What effect does increasing altitude have on stability?

#40. If the yaw damper fails when flying at cruising speed at maximum altitude?

#41. Spiral instability is likely when?

#42. In phugoid motion?

#43. What effect does CD have on phugoid characteristics?

#44. How can a pilot stop short period motion?

#45. Constant amplitude oscillations about any axis are?

#46. A ventral fin will?

#47. A ventral fin will?

#48. A ventral fin will?

#49. Longitudinal stability requires?

#50. What effect does dihedral have on the stick force necessary to maintain sideslip?

#51. Dutch Roll tendency is increased by?

#52. C of G on forward limit?

#53. What is short period mode?

#54. Dutch Roll occurs when ........ stability is greater than .......... stability?

#55. Strong lateral dynamic stability will. .. . . ... Dutch Roll?

#56. ......... increases manoeuvrability?

#57. Sweepback produces .......?

#58. Sweepback produces?

#59. ............... increases manoeuvrability?

#60. Dutch Roll is?

#61. Which of the following statements is true?

#62. Which of the following statements is true?

#63. Which of the following is true?

#64. Positive longitudinal stability requires a .............. CM:a slope?

#65. Positive lateral stability requires a ............ Cl:B slope?

#66. Positive directional stability requires a .............. Cn:B slope?

#67. Stick free stability is ............ stick fixed stability?

#68. An in limits aft C of G will .......... stick force gradient?

#69. A dorsal fin ................ the effectiveness of the fin by ..............?

#70. A fin with a dorsal fin will have a ........... CL:B slope and a ......... stalling angle compared to one without ?

#71. Increasing fin height will ........... static lateral stability and .......... dynamic lateral stability?

#72. Increasing fin height will ............ static directional stability and ......... dynamic directional stability?

#73. Adding a ventral fin will............ static lateral stability and .. ....... directional stability?

#74. Adding a dorsal fin will . . . . . . . . .. The tendency to spiral instability?

#75. Adding a ventral fin will ...... tendency to Dutch Roll?

#76. Longitudinal static stability requires a?

#77. Lateral static stability requires a?

#78. Directional static stability requires a?