MOD.8 (PARTE 4) - BASICS OF AERODYNAMICS

1) A swept wing tends to stall first at the: root. tip. centre section.

2) Krueger Flaps are normally fitted to: the trailing edge of the wings. the tips of the wings. the leading edge of the wings.

3) Aspect ratio of a wing is defined as the ratio of the: wingspan to the wing root. square of the chord to the wingspan. wingspan to the mean chord.

4) The trailing vortex on a pointed wing (taper ratio = 0) is: at the root. at the tip. equally all along the wing span.

5) A high wing aircraft will be more: laterally stable than a low wing aircraft. longitudinally stable than a low wing aircraft. directionally stable than a low wing aircraft.

6) A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have: increased drag at high angles of attack. a high stall speed. poor control qualities at low airspeeds.

7) The lift curve for a delta wing is: more steep than that of a high aspect ratio wing. less steep than that of a high aspect ratio wing. the same as that of a high aspect ratio wing.

8) after an aircraft has been disturbed from its straight and level flight, it returns to its original attitude with a small amount of decreasing oscillation. The aircraft is: statically stable but dynamically unstable. statically unstable but dynamically stable. statically stable and dynamically stable.

9) An increase in the speed at which an aerofoil passes through the air increases lift because: the increased speed of the airflow creates a greater pressure differential between the upper and lower surfaces. the increased speed of the airflow creates a lesser pressure differential between the upper and lower surfaces. the increased velocity of the relative wind increases the angle of attack.

10) A delta wing has: a higher stall angle than a straight wing. a lower stall angle than a straight wing. the same stall angle than a straight wing.

11) The Lift/Drag ratio of a wing at the stalling angle is: of a negative value. low. high.

12) The airflow over the upper surface of a cambered wing: increases in velocity and pressure. increases in velocity and reduces in pressure. reduces in velocity and increases in pressure.

13) The speed of air over a swept wing which contributes to the lift is: less than the aircraft speed. more than the aircraft speed. the same as the aircraft speed.

14) For a given angle of attack induced drag is: greater on a high aspect ratio wing. greater towards the wing root. greater on a low aspect ratio wing.

15) In straight and level flight, the angle of attack of a swept wing is: the same as the aircraft angle to the horizontal. more than the aircraft angle to the horizontal. less than the aircraft angle to the horizontal.

16) Induced drag: is never equal to the profile drag. is equal to the profile drag at the stalling speed. is equal to the profile drag at Vmd.

17) A delta wing aircraft flying at the same speed (subsonic) and angle of attack as a swept wing aircraft of similar wing area will produce: the same lift. more lift. less lift.

18) The stagnation point is: static pressure plus dynamic pressure. static pressure minus dynamic pressure. dynamic pressure only.

19) On a swept wing aircraft, due to the adverse pressure gradient, the boundary layer on the upper surface of the wing tends to flow: directly from leading edge to trailing edge. towards the tip. towards the root.

20) With increased speed in level flight: induced drag increases. profile drag increases. profile drag remains constant.

21) If a swept wing stalls at the tips first, the aircraft will: pitch nose up. pitch nose down. roll.

22) The thickness/chord ratio of the wing is also known as: aspect ratio. mean chord ratio. fineness ratio.

23) Flexure of a rearward swept wing will: increase the lift and hence increase the flexure. decrease the lift and hence decrease the flexure. increase the lift and hence decrease the flexure.

24) A High Aspect Ratio wing is a wing with: long span, long chord. long span, short chord. short span, long chord.

25) Stall commencing at the root is preferred because: the ailerons become ineffective. it provides the pilot with a warning of complete loss of lift. it will cause the aircraft to pitch nose up.

26) An aircraft flying in “ground effect” will produce?. more lift than a similar aircraft outside of ground effect. less lift than a similar aircraft outside of ground effect. the same lift as a similar aircraft outside of ground effect.

27) If the angle of attack of a wing is increased in flight, the: C of P will move forward. C of G will move aft. C of P will move aft.

28) The Rams Horn Vortex on a forward swept wing will be: the same as a rearward swept wing. more than a rearward swept wing. less than a rearward swept wing.

29) When maintaining level flight an increase in speed will: cause the C of P to move aft. cause the C of P to move forward. have no affect on the position of the C of P.

30) For a cambered wing section the zero lift angle of attack will be: zero. 4 degrees. negative.

31) Density changes with altitude at a rate: of 2kg/m^3 per 1000ft. which changes with altitude. which is constant until 11km.

32) Airflow at subsonic speed is taken to be: compressible. incompressible. either a or b depending on altitude.

33) Bernoulli's equation shows that: at constant velocity the kinetic energy of the air changes with a change of height. with a change in speed at constant height both kinetic and potential energies change. with a change in velocity at constant height the static pressure will change.

34) If fluid flow through a venturi is said to be incompressible, the speed of the flow increases at the throat to: maintain a constant volume flow rate. allow for a reduction in static pressure. allow for an increase in static pressure.

35) to produce lift, an aerofoil must be: asymmetrical. symmetrical. either a or b above.

36) Lift is dependent on: the area of the wing, the density of the fluid medium, and the square of the velocity. the net area of the wing ,the density of the fluid medium and the velocity. the frontal area of the wing, the density of the fluid medium and the velocity.

37) The maximum lift/drag ratio of a wing occurs: at the angle of attack where the wing develops its maximum lift. during take off. at an angle below which the wing develops max lift.

38) A wing develops 10,000N of lift at 100knots. Assuming the wing remains at the same angle of attack and remains at the same altitude, how much lift will it develop at 300knots?. 900,000 N. 90,000N. 30,000N.

39) The angle of attack is: related to angle of incidence. always kept below 15 degrees. not related to the angle of incidence.

40) The difference between the mean camber line and the chord line of an aerofoil is: one is always straight and the other may be straight. neither are straight. they both may be curved.

41) If the C of G is calculated after loading as within limits for take off: no further calculation is required. a further calculation is required prior to landing to allow for fuel and oil consumption. a further calculation is required prior to landing to allow for flap deployment.

42) A stalled aerofoil has a lift/drag ratio: more than the lift/drag ratio prior to stall. zero. less than the lift/drag ratio prior to stall.

43) At low forward speed: increased downwash reduces tailplane effectiveness. increased downwash increases tailplane effectiveness. excessive rudder movement may cause fin to stall.

44) Helicopter rotor blades create lift by: creating low pressure above the blades. pushing the air down. working like a screw.

45) On some modern aircraft a stall warning will automatically: increase thrust. extend outboard slats. cause a pitch nose down movement.

46) above 65,800 ft temperature: remains constant up to 115,000ft. decreases by 1.98oC up to 115000ft. increases by 0.303oC up to 115000ft.

47) At sea level, ISA atmospheric pressure is: 14.7 PSI. 14.7 Kpa. 10 Bar.

48) The spanwise component of the airflow is: greater at higher speeds. less at higher speeds. unaffected by speed.

49) A wing fence: increases lateral control. acts as a lift dumping device. reduces spanwise flow on a swept wing thus reducing induced drag.

50) The highest lift/drag ratio is greatest at: low altitudes. the point just before the stalling angle. the optimum angle of attack.

51) With all conditions remaining the same, if the aircraft speed is halved, by what factor is the lift reduced?. Half. By a factor of 4. Remains the same.

52) The boundary layer over an aerofoil is: a layer of air close to the aerofoil that is stationary. a layer of air close to the aerofoil which is moving at a velocity less than free stream air. a layer of turbulent air close to the aerofoil which is moving at a velocity less than free stream air.

53) on a swept wing aircraft, the fineness ratio of an aerofoil is: highest at the root. highest at the tip. equal throughout the span.

54) IAS for a stall will: increase with altitude. decrease with altitude. roughly remain the same for all altitude.

55) If the radius of a turn is reduced the load factor will: increase. decrease. remain the same.

56) Streamlining will reduce: form drag. induced drag. skin friction drag.

57) If an aircraft has a gross weight of 3000 kg and is then subjected to a total weight of 6000 kg the load factor will be: 2G. 3G. 9G.

58) A constant rate of climb is determined by: weight. wind speed. excess engine power.

59) Ice formed on the leading edge will cause the aircraft to: stall at the same stall speed and AoA. stall at a lower speed. stall at a higher speed.

60) With an aircraft in bank, the upper wing produces more drag. To compensate: the rudder is operated. when bank angle is achieved then the ailerons are operated in the opposite direction to cause the opposite effect. angle of attack is increased.

61) on a high winged aircraft in a banked turn, which of the following are true?. The down-going wing loses lift causing a stabilizing effect. The up-going wing loses lift causing a stabilizing effect. The wing dihedral causes a stabilizing effect.

62) If an aircraft true airspeed is halved, its indicated airspeed is reduced by: half. factor of four. It is not reduced, it is doubled.

63) If there is an increase of density, what effect would there be in aerodynamic dampening?. None. Decreased. Increased.

64) As Mach number increases, what is the effect on boundary layer?. Becomes more turbulent. Becomes less turbulent. Decreases in thickness.

65) When a slat is retracted it moves: towards the upper leading edge of the wing. towards the lower leading edge of the wing. towards the center of the leading edge of the wing.

66) In a turn the up-going wing causes a: de-stabilizing effect due to increased AoA. de-stabilizing effect due to decreased AoA. stabilizing effect due to decreased AoA.

67) The stagnation point consists of: dynamic and static air pressure. static air pressure. dynamic air pressure.

68) During a glide the following forces act on an aircraft: lift, weight, thrust. lift, drag, weight. lift and weight only.

69) Yawing is a rotation around: the normal axis obtained by the elevator. the lateral axis obtained by the rudder. the normal axis obtained by the rudder.

70) If an aileron is moved downward: the stalling angle of that wing is increased. the stalling angle of that wing is decreased. the stalling angle is not affected but the stalling speed is decreased.

71) If the wing loading of an aircraft were reduced the stalling speed would: increase. decrease. not be affected.

72) As the angle of attack increases the centre of pressure will: move rearward. remain static. move forward.

73) The lift on a wing is increased with: an increase in pressure. an increase in humidity. an increase in temperature.

74) An aircraft entering a level turn will require more lift: only if there is an increase in speed. only if there is an increase in angle of attack. in all cases.

75) Lateral stability is reduced by increasing: Anhedral. Dihedral. Sweepback.

76) Pulling the control column and rotating to the left causes: elevator down, left aileron down. elevator up, left aileron up. elevator down, left aileron up.

77) Azimuth stability is dependent on: dihedral. tailplane. keel and fin.

78) If the aircraft is slipping in turn: the bank angle is too great. the bank angle is too small. the nose of the aircraft is too low.

79) in normal flight conditions, an increase in aircraft speed: causes the nose of the aircraft to drop. causes the nose of the aircraft to lift. the nose remains in the same position.

80) An aircraft sideslips. What helps to restore the aircraft?. Fin gives rolling movement. Dihedral causes the aircraft to roll straight and the fin increases the yaw rate. Tailplane.

81) For an aircraft climbing at a constant IAS the Mach number will: increase. decrease. remain constant.

82) The airflow behind a normal shockwave will: always be subsonic and in the same direction as the original airflow. always be supersonic and in the same direction as the original airflow. always be subsonic and deflected from the direction of the original airflow.

83) Sweepback of the wings will: not affect lateral stability. increase lateral stability at high speeds only. increase lateral stability at all speeds.

84) With the flaps lowered, the stalling speed will: increase. decrease. remain the same.

85) When flying close to the stall speed a pilot applies left rudder the aircraft will: pitch nose up. roll to the left. stall the left wing.

86) When an aircraft is in a bank, the upper wing produces more drag. To compensate: the rudder is operated. when bank angle is achieved then the ailerons are operated in the opposite direction to cause the opposite effect. angle of attack is increased (pitch up).

87) When flaps are down it will: increase AoA and increase slow speed stability. decrease AoA and decrease slow speed stability. the AoA remains the same on both wings.