AERODYNAMICS
01. The earth’s atmosphere can be said to consists of four concentric gaseous layers.
The order stating from the earth surface is:
a. Tropopause, stratosphere, Mesophere and Thermosphere
b. Tropopause, Mesophere, Stratosphere and Tropopause
c. Stratosphere, Tropopause, Mesophere and Thermosphere
d. Troposphere, Stratosphere Mesophere and Thermosphere
02. In the stratosphere Temperature
a. Remain constant
b. Decreases at a steady rate
c. Increase at a steady rate
d. Increase or decrease depends on the activity of the sun
03. Which of the following statement is true?
a. Air is compressible fluid.
b. Air is an incompressible fluid.
c. Air is a compressible compound.
d. Air is a incompressible mixture.
04 At any point in fluid,
a. The pressure is, same in all direction.
b. The pressure is same and inversly proportional to the depth.
c. The temperature is same.
d. All above statements are wrong.
05. Which of the following statement is true?
a. There is no water vapour above 25330 ft at the equator.
b. Water vapor is found only up to 7500 ft.
c. The higher the temperature the greater the amount of water vapor that air can hold.
d. The lower the temperature greater the amount of water vapour that air can hold.
06. Which of the following statement is true?
a. Moisture does not mix with atmospheric air.
b. Moist air produce more power.
c. Moist air is lighter than air.
d. Moist air is heavier than air.
07. The speed of sound?
a. Remain constant in the troposphere.
b. Decrease with the altitude.
c. Increase with the altitude.
d. Remain constant in the stratosphere.
08. ½ mv2 is the formula that express
a. The dynamic pressure of a gas in motion.
b. Static pressure of gas in motion
c. Amount of potential energy in a gas.
d. The difference in kinetic energy and the dynamic pressure in a gas in motion.
09. Form drag could be reduced by
a. Re- energizing the boundary layer.
b. By producing less lift.
c. By giving smooth outer finish to an object.
d. By giving a streame line shape to the object.
10. The profile drag is combination of
a. Induce drag and parasitic drag.
b. Form drag, interference drag and skin friction.
c. Form drag, skin friction and induce drag.
d. Skin friction and induce drag.
11. The amount of skin friction is largely depend on
a. Smoothness of the surface.
b. Shape of the object.
c. Shape of the upper camber.
d. Shape of the lower camber.
12. The ratio of the length and breadth of any stremeline body known as
a. Finess ratio.
b. Drag ratio.
c. Aspect ratio.
d. Lift / drag ratio.
13. The chord line of an aerofoil is defined as
a. Line that devide the aerofoil into two equal parts.
b. The straight line that joining the leading edge to the trailing.
c. Line joining leading edge to the trailing edge, equi- distant from upper and lower camber
surface.
14. Wing loading is
a. Total weight of the a/c divided by the total lift produce by the wing.
b. Weight of the a/c divided by the wing area.
c. Wing area of the a/c divided by the weight of the a/c.
d. Total lift produce by the wing, divided by the weight of the a/c.
15. The operation of the flap is to
a. Increase the angle of attack.
b. To improve the boundary layer.
c. To re- energize the boundary layer.
d. Raise the camber of the wing section and the plan area.
16. The reason to have induce drag is
a. Very high lift/ drag ratio.
b. High aspect ratio.
c. High angle of attack.
d. Wing tip vortices.
17. Which of the following factor contributes for the surface friction drag?
a. Boundary layer.
b. Angle of attack.
c. High camber.
d. Aspect ratio.
18. Differential ailerons means
a. For a given control stick movement, the up – going aileron is deflected through a smaller
angle than the down going aileron.
b. For a given stick movement the up – going aileron is deflected through a smaller angle than the down going aileron.
c. For a given deflection of the up going aileron control stick will deflect more fore ward left.
d. For a given deflection of the down going aileron control stick will deflect more forward right.
19. In fries aileron
a. Nose of the down going aileron protrudes in to the air speed below the wing to increase the drag on the down going wing.
b. Nose of the up going aileron protrudes in to the air stream below the wing to increase the drag on the down going wing.
c. Nose of the down going aileron and the nose of the up going elevator is protruding out, to increase the drag.
20. To over come the adverse yaw
a. Is to gear the rudder servo tab to control stick.
b. Is to gear the aileron servo tab to control stick.
c. Is to gear the rudder to aileron.
d. Is to gear the aileron to rudder servo tab.
20. A, Rectified air speed is
a. When I.A.S. is corrected for pressure error correction and instrument error correction.
b. When I.A.S. corrected for pressure error only.
c. When I.A.S. corrected for instrument error only.
d. When I.A.S. is corrected for pressure error, instrument error and compressibility error.
20. B,
Above figure is
a. Laminar how: (A) Is stagnation point, A to B is turbulent (B) Is separation point, B to C is Laminar and C is transition point.
b. Boundary Layer: A is stagnation point A to B is turbulent, (B) Is transition point and B to C is Irrotational how and C is separation point.
c. Boundary Layer: A is stagnation point, A to B is Laminar and B is transition point and B to C is turbulent and C is separation point.
d. All above answers are wrong.
21. The function of a tail plane is
a. Any force necessary to counter residual pitching moment arising from in equalities in the main couple.
b. A force necessary to balance the four forces.
c. Forces necessary to balance the aircraft in the lateral axis.
d. Forces necessary to augment lift in the tail area
22. The transition point is the point at which
a. The boundary layer changes in to turbulent
b. The boundary layer start separating.
c. The free stream velocity decreases due to lose of kinetic energy.
d. The free stream velocity increases due to absorption of kinetic energy.
23 The angle of incidence is that angle formed by
a. The angular difference between the setting of the main aerofoil and the horizontal stabilizer in reference to the longitudinal axis of the aircraft.
b. The angular difference between the wing setting of the two wings of a bi- plane.
c. A line parallel to the wing chord and line parallel to the horizontal axis.
d. A line parallel to the wing, from root to tip, and a line parallel to the lateral axis of the aircraft.
24. As the angle of attack of an aerofoil increases, the centre or pressure will
a. Move towards the trailing edge.
b. Remain stationery because both lift and drag components increase proportionally to increase angle of attack.
c. Remain stationery because of no change in the incidence angle.
d. Move towards the leading the edge.
25. If a pilot reports that his aircraft flew left wing heavy, condition could be corrected
a. By bending the trimming Tab on the stbd wing down.
b. By bending the fixed trimming tab, on port wing down.
c. By bending the trimming on tab on the stbd wing up.
d. All above answers are wrong, left aileron mass balance should be changed.
26. An aircraft centre of lift is usually located aft of its centre of gravity.
a. So that the aircraft will have a tail down tendency, when engine stops.
b. So that the aircraft will have an nose heavy tendency, when engine stop.
c. Since it is impossible to predict the exact location of either it is considered next best to having them both fall at the same point.
d. To improve the stability about the longitudinal axis.
27. If the control stick of an aircraft, is moved rearwards, and to the left, the stbd aileron will move
a. Down and the elevator will move down.
b. Up and the elevator will move down.
c. Up and the elevator will move up.
d. Down and the elevator will move up.
28. If the control stick of an aircraft, with poorly rigged flight controls is moved to forward and to
the and the right, the life aileron will move
a. Up and the elevator will move down.
b. Up and the elevator will move up.
c. Down and the elevator will move up.
d. Down and the elevator move down.
29. Why should the control surface should be mass balanced
a. To hold the surface stream line when on the ground.
b. To make the control surface tab unnecessary.
c. To correct installation rigging error.
d. To reduce the possibility of control surface flutter.
30 The angle of incidence of an aircraft
a. Is change by the pilot as he ascends
b. Affects the dihedral of the wings.
c. Is that angle between the relative wind and the chord of the wings.
d. Does not change in flight.
31. The purpose of leading edge slats is to
a. Reduce stalling speed.
b. Replace flaps.
c. Act as a dive brake speed brake
d. Increse speed on the take off.
32. When the lift of an aerofoil increases, the drag will
a. Decreases.
b. Not be affected.
c. Also increases.
d. Increases while the lift increases, but will return to its original valve.
33. The elevators are used to provide rotation about the
a. Longitudinal axis.
b. Lateral axis.
c. Directional axis.
d. Combination of two of the above.
34. Even through the maximum lift is produced at approximately, 17 degrees, wigs of an a/c is usally set
at 3 to 4 degrees the reason is
a. The fitment of an main plane to retain 17 degrees is difficult from structural strength point of view.
b. At 17 degrees, lift as well as drag is increased, there fore lift/ drage ratio is less.
c. At 17 degrees is very close to the stalling angle, to prevent pilot putting the a/c in to a stall.
d. High angle of attack will affect the C of G limits.
36. The stalling angle is the
a. Angle at which the boundary layer get separated.
b. Angle at which the first signs of stalling appears.
c. Angle at which the aerofoil stalls exactly.
d. The angle at which the maximum lift is obtained.
37. 70 % of the total aerodynamics reaction is produce from
a. Low pressure at the upper surface of the wing.
b. High pressure at the upper surface of the wing.
c. High pressure at the lower surface of the wing.
d. low pressure at the lower surface of the wing.
38. An a/c with a permanent flying fault yaw to port
a. Rudder trimmer should be moved to port.
b. Rudder trimmer should be moved to STBD.
c. Rudder trimmer moved to port and, aileron trimmer should be moved up.
d. Rudder trimmer moved to STBD and, aileron trimmer moved down.
39. An a/c with a permanent flying fault, nose heavy could be corrected by
a. Moving the elevator trimmer down.
b. Moving the elevator trimmer up.
c. Moving the elevator trimmer down and the application of more power.
d. Moving the elevator trimmer up and reducing the power.
40. Which of the following drag increase with the velocity?
a. Induce drag
b. Profile drag
c. Lift dependent drag
d. All above answers are correct.
41. The effort required to move any control surface is determined by
a. Aerodynamic force acting through the C of P of the aerofoil multiplied by the distance from the hinge line
b. Aerodynamic force acting through the C of G of the aerofoil multiplied by the distance from the hinge line
c. Drag force acting through the C of P multiplied by the distance from the hinge line
d. The amount of the force applied by the pilot multiplied by the distance from the control stick to the control surface
42. The angle of glide is decided by the
a. Weight/ Drag ratio.
b. Thrust Angle/ Angle of Attack.
c. Lift / Weight ratio
d. Lift / Drag ratio.
43. If an A/C is statically stable
a. Always dynamically stable.
b. Could be dynamically unstable.
c. Always dynamically neutral.
d. All above answerers are wrong.
44. Out ward and upward inclination of the main plane is defined as.
a. Lateral dihedral angle.
b. Lateral annhedral angle.
c. Longitudinal dihedral angle.
d. Longitudinal annhedral angle.
45. Downward and out ward inclination of the main plane is termed
a. Lateral dihedral angle
b. Annhedral Angle
c. Longitudinal dihedral angle
d. Main plane cannot be fitted like that
46. Which of the following conditions does not contributes for lateral stability.
a Lateral dihedral angle
b Sweep back wings
c. Placing most of the keel surface below the C of G
d. High wing and low C of G.
47. Which of the following factors can affect stalling?
a. Weight of the aircraft.
b. Indicated airspeed.
c. Angle of attack.
d. All above answers are correct.
48. Aspect ratio is defined as:
a. Span/chord
b. Chord /Span
c. Span squared / area for a tapered wing
d. Both A and C answers are correct
49. Flow of the boundary layer is considered as:
a. Rotational flow.
b. Irrotational flow.
c. partially irrigational and partially rotational flow
d. All above answers are wrong.
50. By increasing the aspect ratio.
a. Induced drag is reduced
b. Induced drag is increased.
c. Profile drag is reduced.
d. From drag is increased.
51. The ICAO standard atmosphere assumes a mean sea level temperature of:
a. + 15 o C and a pressure of 1013.25 MB
b. -15 o C and a pressure 14.7 P.S.I.
c. .0 o C and a pressure of 1013.25 MB
d. Answer ‘a’ is correct for northern hemisphere and answer ‘b’ is correct for southern
hemisphere.
52. A fluid in which there is no cohesion between the molecules and therefore no internal friction and incompressible is known as:
a. A colloidal solution.
b. Semi solid liquid.
c. A vision fluid.
d. An ideal fluid.
53. The ICAO standard atmosphere temperature lapse rate is assumed to be:
a. Uniform at the rate of 10 C o per kilo meter.
b. Uniform at the rate of 6.5 C o per kilo meter.
c. Uniform at the rate of 1 o C per kilo meter up to a height of 36090 ft.
d. Uniform at the rate of 6.5o C per kilo meter up to a height of 11 Km above
which height remains constant at -56.5o C.
54. Equivalent Air Speed Is:
a. IAS divided by true air speed.
b. Rectified air speed is corrected for pressure error and instrument error.
c. By adding the compressibility error correction to rectified the air speed.
d. IAS divided by the square of the relative air density.
55. Load factor id defined as:
a. Useable load after zero fuel weight.
b. Load that is acting on a single wheel when the aircraft stationary on ground.
c. Total weight divided by the wing area.
d. Total lift divided by the weight.
56. Drag caused when conflicting air flows meet at he point where one component of the aircraft is attached to another is known as:
a. Induce drag
b. Profile drag
c. Interference drag
d. Form drag
57. Rate of climb of an aircraft is determined by:
a. Thrust/drag ratio
b. Lift drag ratio
c. Amount of excess thrust available.
d. Amount of excess power available
58. Angle of climb of an aircraft is determine by:
a. Thrust/ drag ratio
b. Lift drag ratio
c. Amount of excess thrust available
d. Amount of excess power available.
59. Absolute ceiling of an aircraft is defined as:
a. Altitude at which the maximum power available curve touches the power required curve
b. Altitude at which maximum thrust available curve touches the thrust required curve.
c. Altitude at which maximum power available curve touches the thrust required curve.
60. Design features by which lateral stability could be achieved is as follows:
i. Annhedral angle.
ii. Sweep back wings.
iii.Parasol type wing (high wing)
iv. Side surface below the central of gravity of the aircraft.
a. Only ii. and iii. are correct.
b. Only i. and iv. are correct.
c. Only iii. and iv. are correct.
d. Only i., ii. and iii. are correct.
61. Wing is given a geometric twist or wash out to;
a. Decrease profile drag.
b. Decrease the induce drag
c. In order to prevent tip stall and favour the root stall first.
d. To counter act adverse yaw.
62. Aircraft with a short fuselage has a larger fin area:
a. To improve the stability on lateral axis.
b. To improve the stability on longitudinal axis.
c. To improve the stability on vertical axis.
d. To improve the control over vertical axis.
63. Effect of flap on the stalling angle is:
a. Stalling angle is increased for the first two flap setting and then it is lowered.
b. Decrease the stalling angle
c. Increases the stalling angle.
d. Stalling angle is not affected.
64. When the speed is reduced by half, the control deflection is increased four fold to achieve the
same affect.
a. It is a wrong statement.
b. It is a true statement.
c. It is true statement only if the AUW is move than 12500 ibs.
d. It is true only if the AUW is less than 12500 ibs.
65. Secondary affect of pulling the control column back is:
a. Yaw to the left.
b. Yaw to the right.
c. A decrease in speed.
d. ‘a’ and ‘c’ both are correct.
66. Secondary affect of role to port is:
a. Yaw to port.
b. Yaw to starboard.
c. Pitch up
d. Pitch down.
67. On an humid day the lift of a wing could be:
a. Same as a normal day.
b. Greater.
c. Lesser.
d. Humidity has no affect on lift.
68. To get the same range in a glide A/C should maintain the
a. A o A which is just below the stalling angle.
b. A o A at which the lift drag ratio is maintained.
c. Nose up attitude which thrust more than the drag.
d. Nose down attitude with thrust less than the drag.
69. The weight of an aircraft is:
a. Directly proportional to the gliding angle.
b. Does not affects the gliding speed.
c. Effects the gliding angle.
d. Does not effects the gilding angle.
70. Properly co – ordinated turn of an aircraft could be ascertained by:
a. Air speed indicator.
b. Turn and slip indicator.
c. Rate of climb.
d. Artificial horizon.
71. The aerodynamic centre is:
a. The point at which the moment coefficient is relatively constant for all angles of attack.
b. The point at which the lift coefficient is relatively constant for all angles of attack.
c. The point at which the drag coefficient is relatively constant for all angles of attack.
d. The point at which the moment coefficient is relatively constant for all indicated air speed.
72. Zooming is a process by which:
a. Aircraft gains height by converting kinetic energy to potential energy.
b. Aircraft gain height by converting potential energy to kinetic energy.
c. Aircraft gain speed by converting potential energy to kinetic energy.
d. Answer ‘a’ and ‘c’ both are correct.
73. The function of the vortex generator is:
a. Reduces the boundary layer height and reduces he separation of it.
b. Increases the boundary layer height and increases the separation of it.
c. Reduces the boundary layer height and increases the separation of it.
d. Increases the boundary layer height and reduces the separation of it.
74. In an steady flight the sum of opposing forces acting on an aircraft is equal to:
a. Total weight of the aircraft.
b. Total weight of the aircraft plus total drag.
c. Total weight plus ‘G’ loads.
d. Zero.
