LIFT AND DRAG – Air – DGCA Question Bank For Politics

#1. Which of the following statements is most accurate?

D1 is proportional to 1 / (EAS)2

D1 is proportional to 1 I (IAS)2

D1 is proportional to 1 I (RAS)2

D1 is proportional to 1 I (TAS)2

#2. Which of the following statements is most accurate?

D1 is proportional to L.

D1 is proportional to L/V.

D1 is proportional to 1/L.

D1 is proportional to V/L.

#3. If a 50000 Ibf aircraft requires 25000 lbf of thrust maintain unaccelerated straight and level flight at 250 Kts what is its L:D ratio?

1:2.

2:1.

10:1

20:1

#4. What effect does increasing load factor have on power required at any given aircraft weight and TAS?

No effect.

Increases in direct proportion to load factor.

Decreases in direct proportion to load factor.

Power required is inversely proportional to load factor.

#5. What effect will increasing weight have on DI, Dp and DTotal at any given load factor and airspeed?

Increase, No significant effect, Increase.

Increase, Decrease, No significant effect.

Decrease, Increase, No significant effect.

Decrease, No significant effect, Increase.

#6. What effect will increasing aircraft weight have on minimum drag speed (VMD) and speed stability.

Increase, Increase.

Increase, Decrease.

Decrease, Increase.

Decrease, Decrease.

#7. What effect will lowering the landing gear have on VMD and speed stability?

Increase, Increase.

Increase, Decrease.

Decrease, Increase.

Decrease, Decrease.

#8. What is the effect on D1 and Dp when an aircraft climbs to altitude at constant low IAS .

Increase, Increase.

Increase, Decrease.

No change, No change.

Decrease, Decrease.

#9. What would be the effect on Dl, Dp and speed stability if the trailing edge flaps of an aircraft were lowered to the 10 degree setting while maintaining constant speed and wings level?

Increase, Increase, Increase.

Increase, Increase, Decrease.

Decrease, Increase, Increase.

Decrease, Decrease, Decrease.

#10. What would be the effect on Dl, Dp and speed stability if the trailing edge flaps of an aircraft were lowered to the 40 degree setting while maintaining constant speed and wings level?

Increase, Increase, Increase.

Increase, Increase, Decrease.

Decrease, Increase, Increase.

Decrease, Decrease, Decrease.

#11. What will be the effect on drag if humidity is increased if air temperature, pressure and TAS remain constant?

Increase.

Decrease.

Remain constant.

Decrease or increase depending on Mach number.

#12. When flying at best L:D ratio what is the ratio of Dp: Dl?

2:1

1:1

1:2

Depends on aerofoil section.

#13. Which of the following occur at VMD?

Minimum power required and best L:D ratio.

Minimum drag and greatest L:D ratio.

Minimum angle of attack and best rate of climb.

Minimum drag and greatest jet propeller aircraft range.

#14. In what direction does the drag force act?

Parallel to relative airflow.

Parallel but opposite to the direction of flight.

Parallel to lift.

Parallel to weight.

#15. Which of the following statements are true of the total reaction generated by a wing flying at zero lift angle of attack.

It equals Dp.

It equals DI.

It equals weight.

It is twice Dp.

#16. In what direction does the total reaction act when a wing is flying at its zero lift angle of attack?

Parallel but opposite to the direction of flight.

Vertically aft through the C of G.

Vertically upward through the aerodynamic centre

Vertically aft such that it produces a nose up pitching moment.

#17. What is the relationship between Dl and Dp at speeds below VMD?

Dl is greater than Dp

Dl is less than Dp.

Dl = Dp.

Dl = Dp = DTotal.

#18. Complete the following statement. As airspeed changes from VMO to CLMax ................ increases and .............. decreases.

Dl, DP.

DP, DI.

DTotal, Dp.

DTotal, Dl.

#19. Which of the following definitions of Dp is the most accurate?

It is made up of form, friction and induced drag.

It is made up of friction, induced and shock drag.

It is made up of friction, form and interference drag.

It is made up of interference, shock and form drag.

#20. Which of the following statements concerning the generation of lift is most accurate?

Lift is generated by a cambered aerofoil.

Lift is generated by an aerofoil at a positive angle.

Lift is generated by high speed airflow.

Lift is generated by the downward acceleration of air.

#21. Which of the following causes induced drag (Dl)?

Shock waves above and below the wing.

Friction due to the air passing over the wing.

Rotating airflow caused by wing tip vortices.

The upwash of air caused by wingtip vortices.

#22. Which of the following causes induced drag (Dl)?

Shock waves above and below the wing.

Friction due to the air passing over the wing.

Downwash of airflow over the trailing edge caused by wing tip vortices

Upwash of airflow over the trailing edge caused by wingtip vortices.

#23. A model of an aerofoil is placed in a rectangular wind tunnel such that its tips are embedded in the sides of the tunnel. Which of the following statements best represents the flow of air over the aerofoil when it is generating a lift force.

Because the wing effectively has no wingtips there will be no tip vortices and no downwash.

Because the wing is generating lift there will be downwash but this will be reduced by the effective lack of wingtips.

Downwash will not be reduced by the lack of wingtips.

The wing is effectively tw"o dimensional so its CL:a curve will be vertical. It will therefore produce no induced drag.

#24. If it were possible to build and fly a wing of infinite length how much downwash would it create and what would be the shape of its CL:a curve?

No downwash, Vertical CL:a curve.

Little downwash, Shallow CL:a curve.

No downwash, Shallow CL:a curve.

Little downwash, Vertical CL:a curve.

#25. Which of the following is responsible for the creation of induced drag?

Angle of attack, camber, wing area and airspeed.

Pitch angle, camber, wing area and airspeed.

Pitch angle, camber, wing area and angle of attack.

Airspeed, wing area and pitch angle.

#26. What proportion of total drag is made up of induced drag when flying at VMD?

50%

75%

25%

100%

#27. If TAS is increased from 300 Kts to 400 Kts with no change in altitude, configuration or weight, by what percentage will power required change?

Decrease by 135%

Decrease by 35%

Increase by 135%

Increase by 235%

#28. All other factors being equal, minimum drag is ............?

Constant.

Proportional to weight.

A function of density altitude.

A function of pressure altitude.

#29. If air density is reduced by a factor of 4, by what factor will drag alter?

Decrease by a factor of 2.

Decrease by a factor of 4.

Increase by a factor of 4.

Decrease by a factor of 16.

#30. If indicated airspeed is maintained constant while air density decreases by half what will be the effect on total drag?

Increase by a factor of 2.

Decrease by a factor of 2.

Increase by a factor of 4.

Remain unchanged.

#31. In straight and level flight an aircraft has a CL of 0.55. If an upward gust of wind causing a lo increase in angle of attack would increase CL to 0.7, what increase in CL would be produced by an upward gust of twice the intensity?

0.2

0.3

0.4

0.5

#32. If IAS is increased from 100 Kts to 200 Kts, by what factor would DI and CD1 be multiplied?

1/4, 1/2.

1/2, 1/4.

1/4, 1/16.

4, 16.

#33. How does the drag produced by a turbulent boundary layer compare with that of a laminar one?

Identical.

Greater friction drag.

Less friction drag.

Less wave drag.

#34. What is the principal benefit of a turbulent boundary layer?

Less friction drag.

Less form drag.

Later separation.

Earlier transition.

#35. In what direction does the weight of an aircraft act?

At right angles to the flight path.

Opposite lift.

Straight down.

Depends on rate of turn.

#36. In what direction does lift act?

Straight up.

At right angles to the flight path.

At right angles to the relative airflow.

At right angles to thrust.

#37. The majority of lift is produced by?

High pressure below the wing.

Low pressure above the wing.

Increased velocity below the wing.

Increased density below the wing.

#38. How does static pressure below a wing at low positive angles of attack compare with the local ambient static pressure?

Higher.

The same.

Lower.

Higher or lower depending on speed.

#39. Which of the following would give minimum glide gradient?

CL2 /CD Min.

CD2 / CL Max.

CL4/CD min.

CL/CD max.

#40. Which of the following is the correct formula for CD1?

CL2 / kA.

CL2 / kπA.

CL / kA.

CL3 / kπA.

#41. Entering ground effect causes?

Low pressure below the wings reduces lift.

Downwash is increased.

Downwash is reduced.

The aircraft slows down.

#42. How does effective aspect ratio change when leaving ground effect?

Returns to actual value.

Increases.

No effect

Increases or decrease depending on speed.

#43. In what way does ground effect influence induced drag?

lncreases it.

No effect.

Decreases it.

Angles it aft.

#44. A low speed aircraft climbs from sea level to 40000 feet pressure altitude at constant TAS. By what factor will its profile drag be multiplied if all other factors remain unchanged?

1/2.

1/4.

2.

4.

#45. At what height does ground effect become significant?

1 wing span.

2 wing spans.

1/2 wing span.

1/4 wing span.

#46. What will be the effect of raising the undercarriage of an aircraft?

Increased induced drag due to more efficient lift production.

Decreased induced drag due to less efficient lift production.

Increased profile drag and greater speed stability.

Decreased profile drag and lower speed stability.

#47. What causes wing tip vortices?

Pressure differences in front of and behind the wings.

High pressure air leaking from below the wings.

Spanwise flow from tip to root under the wings.

Spanwise flow from root to tip above the wings.

#48. How does aspect ratio affect wingtip vortex strength?

Shorter tip chord length.

Longer tip chord length.

Shorter root chord length.

Higher energy airflow.

#49. If airspeed changes from 200 Kts to 400 Kts by what factor will CDI and CDP change?

2, 2.

1/16, No change.

No change, 1/16.

1/4, 1/4.

#50. How will power required vary when leaving ground effect?

No change.

Increase.

Decrease.

Decrease or increase depending on airspeed.

#51. In what ways are DI and Dp proportional to V?

Inversely.

V3, 1/V3.

V2, 1/V2.

1/V2, V2.

#52. What happens to total drag when increasing speed to V2?

Decreases approximately with the square of speed.

Increases approximately with the square of speed.

Decreases approximately with the inverse of the square of speed.

Remains constant.

#53. If IAS decreases by a factor of 5 how would drag vary?

5.

25.

35.

75.

#54. If IAS decreased by a factor of 5 how would drag vary?

1/5.

1/25.

1/35.

1/75.

#55. If CL increased by a factor of 5 how would CD1 vary?

1/5.

5.

1/25.

25.

#56. If aspect ratio increased by a factor of 2 how would CDI vary?

1/2.

2.

1/4.

4.

#57. How does total drag vary with air density?

Constant.

Directly.

Inversely.

Conversely.

#58. How does laminar boundary layer compare with turbulent boundary layer?

Thinner.

Thicker.

Faster.

The same.

#59. How does a vortex generator energise the boundary layer?

Mixes it wit11 free stream air.

Mixes it with laminar boundary layer.

Mixes it with turbulent boundary layer.

Prevents shock waves.

#60. Which of the following are true of VMD?

Lower than VMp.

Gives best L:D ratio.

Gives best endurance in a,propeller aircraft.

Gives best range in a jet aircraft.

#61. How is drag affected if pressure decreases with TAS and temperature constant?

Increases.

Decreases.

Increase or decrease depending on altitude.

Constant.

#62. How does retraction of flaps affect induced drag if IAS remains constant?

Increases.

Decreases.

Constant.

Increase or decrease depending on speed.

#63. How does deployment of fowler flaps affect aspect ratio and angle of'incidence?

Increases, Decrease.

Decrease, Increase.

Constant, Constant.

Increase, Increase.

#64. If for an elliptical wing the CL = 2.5, A = 4, what is CDI?

0.297

0.497

1.297

1.497

#65. In straight and level flight CL = 0.44. If a gust of wind causing a 1' increase in angle of attack would give a 0.06 increase in CL, what load factor would a gust causing a 5' increase produce?

1.58

1.68

1.78

1.88

#66. What would be the CDI of a wing of aspect ratio 4 and CLMAX 2.5 when operating at zero lift angle of attack?

0.297.

0.497.

1.297.

None of the above.

#67. As the angle of attack of a wing is increased above zero what happens to the stagnation point, transition point and separation point?

Moves forward, Moves aft, Moves aft.

Moves aft, Moves aft, Moves aft.

Moves aft, Moves forward, Moves forward.

Moves aft, Moves aft, Moves forward.

#68. How is lift created?

A symmetrical aerofoil.

A cambered aerofoil.

Downward acceleration of air.

Dynamic pressure.

#69. Why does the downwash caused by wingtip vortices not create extra lift?

Because pressure differences create lift.

Because it is too small.

Because it is negated by equal upwash outboard of the tips.

Because lift is not created by downwash.

#70. What happens to the total reaction when a wing enters ground effect?

Decreases and angles in a more rearward direction.

Increases in magnitude and is angled in a less rearward direction.

Increases and angles in a more rearward direction.

Decreases and angles in a more forward direction.

#71. At low angles of attack the major component of total drag is ............. drag?

Induced.

Vortex.

Shock.

Profile.

#72. At high angles of attack the major component of total drag is ............. drag?

Induced.

Vortex.

Shock.

Profile.

#73. ............. causes induced drag?

Angle of attack.

Aspect ratio.

Boundary layer separation.

The generation of lift.

#74. Induced drag is directly proportional to ............. ?

Angle of attack.

(Lift force)2.

(True airspeed)2

Aspect ratio.

#75. What is CL as a % of CL MAX at 1.5Vs?

34%.

44%.

54%.

64%.

#76. Induced drag is caused by ......... ?

Upwash.

Tip tanks.

High tailplanes.

Wing tip vortices.

#77. Entering ground effect. .......power required?

Increases.

Decreases.

Does not affect.

Increases or decreases depending on height.

#78. Lowering the undercarriage will ........ ?

Increase induced drag and nose down pitching moment.

Decrease induced drag and nose down pitching moment.

Increase profile drag and nose down pitching moment.

Decrease profile drag and nose down pitching moment.

#79. Doubling IAS multiplies drag by.. ..?

2.5.

3.

1.5.

4.

#80. Tripling IAS multiplies drag by .... ?

1/9.

3.

1/6.

4.

#81. For an elliptical wing if CDI = 0.6, A = 4, what is CL?

1.75.

2.75.

3.75.

4.75.

#82. CDI varies .... ?

Directly with CL2 and inversely with aspect ratio.

Directly with speed and aspect ratio.

Directly with wing area and CL.

Directly with angle of attack and speed.

#83. Increasing camber will. ... ?

Increase the gradient of the lift slope.

Decrease the gradient of the lift slope.

Increase CL Max.

Decrease induced drag.

#84. Increasing camber will....?

Increase the gradient of the lift slope.

Decrease the gradient of the lift slope.

Decrease CL Max.

Reduced stalling speed.

#85. Increasing air temperature will.. ..?

Increase the gradient of the lift slope.

Decrease CL max.

Decrease lift at any given CL and TAS.

Increase profile drag.

#86. Increasing humidity will.. . .... ?

Increase CL max.

Increase required CL.

Decrease stalling speed.

Increase profile drag.

#87. To maintain constant angle of climb, when climbing at constant TAS.. . . . .?

Angle of attack must increase.

Angle of attack must decrease.

Angle of attack must remain constant.

IAS must increase.

#88. Which of the following statements are true? 1. Increasing aspect ratio reduces induced drag. 2. Increasing sweep back angle reduces induced drag. 3. Increasing EAS increases induced drag. 4. Increasing CL increases induced drag.

1 and 4.

1,2 and 3.

1,3 and 4.

2,3 and 4.

#89. .............. aircraft weight will ......... ground effect?

Increasing, Increase.

Increasing, Decrease.

Decreasing, Increase.

Decrease, Decrease.

#90. which two of the following statements are most accurate? 1. CDP is approximately constant and Dp is proportional to V2. 2. CDI is proportional to 1/V4 and DI is proportional to v2. 3. The V in a and b above is TAS. 4. The V in a and b above is EAS.

1 and 4.

1 and 3.

1 and 2.

2 and3.

#91. If an upward gust of wind increases CL by 25% by what % will CDI vary?

36%.

46%.

56%.

66%.

#92. What would be the CDI of an elliptical wing if A = 5, and CL = 2?

4/5π.

5/4π.

2π/5.

2/5π.

#93. At 1.3Vs CL would be ..........% of CL Max ?

77.

59.

130.

169.

#94. .......... Landing speed at constant weight will ........ ground effect?

Increasing, Increase.

Increasing, Decrease.

Decreasing, Increase.

Decreasing, Decrease.

#95. .......... Altitude at constant TAS will ......... Dl?

Increasing, Increase.

Increasing, Decrease.

Decreasing, Increase.

Decreasing, Decrease.

#96. Induced drag is increased by ......... weight, ......... airspeed and ........ aspect ratio?

Increasing, Increasing, Increasing.

Increasing, Decreasing, Decreasing.

Increasing, Decreasing, Increasing.

Decreasing, Increasing, Decreasing.

#97. Increasing load factor will .......... Dp, ............. VMD and ........... speed stability?

Increase, Increase, Increase.

Decrease, Decrease, Decrease.

Not affect, Increase, Decrease.

Not affect, Decrease, Increase.

#98. At 0.9 Vs, the CL will be ............ CL Max and CD will be ........... than at 1.1 VS?

Greater than, Greater than.

Greater than, Less than.

Less than, Less than.

Less than, Greater than.

#99. CL is proportional to ............ ?

CDI.

CDI2.

√CDI.

1/CDI2.

Dgca Question Bank For Pilots

Results

#1. Which of the following statements is most accurate?

#2. Which of the following statements is most accurate?

#3. If a 50000 Ibf aircraft requires 25000 lbf of thrust maintain unaccelerated straight and level flight at 250 Kts what is its L:D ratio?

#4. What effect does increasing load factor have on power required at any given aircraft weight and TAS?

#5. What effect will increasing weight have on DI, Dp and DTotal at any given load factor and airspeed?

#6. What effect will increasing aircraft weight have on minimum drag speed (VMD) and speed stability.

#7. What effect will lowering the landing gear have on VMD and speed stability?

#8. What is the effect on D1 and Dp when an aircraft climbs to altitude at constant low IAS .

#9. What would be the effect on Dl, Dp and speed stability if the trailing edge flaps of an aircraft were lowered to the 10 degree setting while maintaining constant speed and wings level?

#10. What would be the effect on Dl, Dp and speed stability if the trailing edge flaps of an aircraft were lowered to the 40 degree setting while maintaining constant speed and wings level?

#11. What will be the effect on drag if humidity is increased if air temperature, pressure and TAS remain constant?

#12. When flying at best L:D ratio what is the ratio of Dp: Dl?

#13. Which of the following occur at VMD?

#14. In what direction does the drag force act?

#15. Which of the following statements are true of the total reaction generated by a wing flying at zero lift angle of attack.

#16. In what direction does the total reaction act when a wing is flying at its zero lift angle of attack?

#17. What is the relationship between Dl and Dp at speeds below VMD?

#18. Complete the following statement. As airspeed changes from VMO to CLMax ................ increases and .............. decreases.

#19. Which of the following definitions of Dp is the most accurate?

#20. Which of the following statements concerning the generation of lift is most accurate?

#21. Which of the following causes induced drag (Dl)?

#22. Which of the following causes induced drag (Dl)?

#23. A model of an aerofoil is placed in a rectangular wind tunnel such that its tips are embedded in the sides of the tunnel. Which of the following statements best represents the flow of air over the aerofoil when it is generating a lift force.

#24. If it were possible to build and fly a wing of infinite length how much downwash would it create and what would be the shape of its CL:a curve?

#25. Which of the following is responsible for the creation of induced drag?

#26. What proportion of total drag is made up of induced drag when flying at VMD?

#27. If TAS is increased from 300 Kts to 400 Kts with no change in altitude, configuration or weight, by what percentage will power required change?

#28. All other factors being equal, minimum drag is ............?

#29. If air density is reduced by a factor of 4, by what factor will drag alter?

#30. If indicated airspeed is maintained constant while air density decreases by half what will be the effect on total drag?

#31. In straight and level flight an aircraft has a CL of 0.55. If an upward gust of wind causing a lo increase in angle of attack would increase CL to 0.7, what increase in CL would be produced by an upward gust of twice the intensity?

#32. If IAS is increased from 100 Kts to 200 Kts, by what factor would DI and CD1 be multiplied?

#33. How does the drag produced by a turbulent boundary layer compare with that of a laminar one?

#34. What is the principal benefit of a turbulent boundary layer?

#35. In what direction does the weight of an aircraft act?

#36. In what direction does lift act?

#37. The majority of lift is produced by?

#38. How does static pressure below a wing at low positive angles of attack compare with the local ambient static pressure?

#39. Which of the following would give minimum glide gradient?

#40. Which of the following is the correct formula for CD1?

#41. Entering ground effect causes?

#42. How does effective aspect ratio change when leaving ground effect?

#43. In what way does ground effect influence induced drag?

#44. A low speed aircraft climbs from sea level to 40000 feet pressure altitude at constant TAS. By what factor will its profile drag be multiplied if all other factors remain unchanged?

#45. At what height does ground effect become significant?

#46. What will be the effect of raising the undercarriage of an aircraft?

#47. What causes wing tip vortices?

#48. How does aspect ratio affect wingtip vortex strength?

#49. If airspeed changes from 200 Kts to 400 Kts by what factor will CDI and CDP change?

#50. How will power required vary when leaving ground effect?

#51. In what ways are DI and Dp proportional to V?

#52. What happens to total drag when increasing speed to V2?

#53. If IAS decreases by a factor of 5 how would drag vary?

#54. If IAS decreased by a factor of 5 how would drag vary?

#55. If CL increased by a factor of 5 how would CD1 vary?

#56. If aspect ratio increased by a factor of 2 how would CDI vary?

#57. How does total drag vary with air density?

#58. How does laminar boundary layer compare with turbulent boundary layer?

#59. How does a vortex generator energise the boundary layer?

#60. Which of the following are true of VMD?

#61. How is drag affected if pressure decreases with TAS and temperature constant?

#62. How does retraction of flaps affect induced drag if IAS remains constant?

#63. How does deployment of fowler flaps affect aspect ratio and angle of'incidence?

#64. If for an elliptical wing the CL = 2.5, A = 4, what is CDI?

#65. In straight and level flight CL = 0.44. If a gust of wind causing a 1' increase in angle of attack would give a 0.06 increase in CL, what load factor would a gust causing a 5' increase produce?

#66. What would be the CDI of a wing of aspect ratio 4 and CLMAX 2.5 when operating at zero lift angle of attack?

#67. As the angle of attack of a wing is increased above zero what happens to the stagnation point, transition point and separation point?

#68. How is lift created?

#69. Why does the downwash caused by wingtip vortices not create extra lift?

#70. What happens to the total reaction when a wing enters ground effect?

#71. At low angles of attack the major component of total drag is ............. drag?

#72. At high angles of attack the major component of total drag is ............. drag?

#73. ............. causes induced drag?

#74. Induced drag is directly proportional to ............. ?

#75. What is CL as a % of CL MAX at 1.5Vs?

#76. Induced drag is caused by ......... ?

#77. Entering ground effect. .......power required?

#78. Lowering the undercarriage will ........ ?