EASA Part 66 : Aerodynamic Question2
Question Number. 188. During inverted level flight an aircraft accelerometer shows. Option A. -2g. Option B. -1g. Option C. 0g.
Correct Answer is. -1g. Explanation. Inverted (level) flight is -1g.
Question Number. 189. During straight and level flight an aircraft accelerometer shows. Option A. 4g. Option B. 1g. Option C. 2g.
Correct Answer is. 1g. Explanation. Straight and level flight is 1g.
Question Number. 158. 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. Option A. 2G. Option B. 9G. Option C. 3G.
Correct Answer is. 2G. Explanation. Load factor is a measure of how many times heavier the aircraft 'feels' compared to how heavy it actually is.
Question Number. 178. _______ angle of attack is known as optimum angle of attack. Option A. 5 to 7 degrees. Option B. 3 to 4 degrees. Option C. 10 to 12 degrees.
Correct Answer is. 3 to 4 degrees. Explanation. NIL.
Question Number. 14. The centre of pressure of an aerofoil is located. Option A. 30 - 40% of the chord line forward of the leading edge. Option B. 50% of the chord line back from the leading edge. Option C. 30 - 40% of the chord line back from the leading edge.
Correct Answer is. 30 - 40% of the chord line back from the leading edge. Explanation. The centre of pressure is positioned roughly 30 - 40 % of the chord line BACK from the leading edge.
Question Number. 147. A wing develops 10,000 N of lift at 100 knots. Assuming the wing remains at the same angle of attack and remains at the same altitude, how much lift will it develop at 300knots?. Option A. 30,000 N. Option B. 900,000 N. Option C. 90,000 N.
Correct Answer is. 90,000 N. Explanation. See the formula for lift. Velocity is squared, so if you triple the velocity, the lift is 9 times.
Question Number. 73. What is the angle between the chord line of the wing, and the longitudinal axis of the aircraft, known as?. Option A. Angle of dihedral. Option B. Angle of attack. Option C. Angle of incidence.
Correct Answer is. Angle of incidence. Explanation. Angle of incidence is the angle between the chord line of the wing and the longitudinal axis of the aircraft.
Question Number. 161. As Mach number increases, what is the effect on boundary layer?. Option A. Becomes more turbulent. Option B. Decreases in thickness. Option C. Becomes less turbulent.
Correct Answer is. Becomes more turbulent. Explanation. As speed increases (speed here is measured in Mach) the transition point moves forward, hence turbulent boundary layer increases.
Question Number. 76. As the angle of attack is increased (up to the stall point), which of the following is correct?. Option A. Both a) and b) are correct. Option B. Pressure difference between top and bottom of the wing increases. Option C. Lift increases.
Correct Answer is. Both a) and b) are correct. Explanation. As the angle of attack is increased the pressure difference between the upper and lower surfaces of the wing is increased. This causes the lift to increase.
Question Number. 154. With all conditions remaining the same, if the aircraft speed is halved, by what factor is the lift reduced?. Option A. Half. Option B. By a factor of 4. Option C. Remains the same.
Correct Answer is. By a factor of 4. Explanation. Lift is proportional to the square of aircraft speed.
Question Number. 139. If the angle of attack of a wing is increased in flight, the. Option A. CofP will move aft. Option B. CofP will move forward. Option C. C of G will move aft.
Correct Answer is. CofP will move forward. Explanation. Increasing the AOA moves the CofP forward.
Question Number. 160. Under what conditions will an aircraft create best lift?. Option A. Hot damp day at 1200 ft. Option B. Cold dry day at 200 ft. Option C. Cold wet day at 1200 ft.
Correct Answer is. Cold dry day at 200 ft. Explanation. Cold dry air at low altitude provides maximum air density hence best lift.
Question Number. 32. What is a controlling factor of turbulence and skin friction?. Option A. Countersunk rivets used on skin exterior. Option B. Aspect ratio. Option C. Fineness ratio.
Correct Answer is. Countersunk rivets used on skin exterior. Explanation. Countersunk rivets increase skin friction and turbulence.
Question Number. 21. "What is the collective term for the fin and rudder and other surfaces aft of the centre of gravity that helps directional stability?." Option A. Empennage. Option B. Fuselage surfaces. Option C. Effective keel surface.
Correct Answer is. Effective keel surface. Explanation. All the side surfaces aft of the centre of gravity which aid the directional stability are collectively called the EFFECTIVE KEEL SURFACE.
Question Number. 101. Profile drag consists of what drag types?. Option A. Form, induced and interference. Option B. Form, induced and skin friction. Option C. Form, skin friction and interference.
Correct Answer is. Form, skin friction and interference. Explanation. Profile drag (known as Parasite drag in the USA) consists of Form Drag, Skin Friction Drag and Interference Drag.
Question Number. 86. Wing loading is. Option A. WING AREA * WING CHORD. Option B. GROSS WEIGHT divided by GROSS WING AREA. Option C. the ultimate tensile strength of the wing.
Correct Answer is. GROSS WEIGHT divided by GROSS WING AREA. Explanation. Wing loading is gross weight divided by wing area measured in Newtons per Square Metre.
Question Number. 191. What produces the most lift at low speeds?. Option A. High camber. Option B. Low aspect ratio. Option C. High aspect ratio.
Correct Answer is. High aspect ratio. Explanation. NIL.
Question Number. 35. What effect would a forward CG have on an aircraft on landing?. Option A. Increase stalling speed. Option B. Reduce stalling speed. Option C. No effect on landing.
Correct Answer is. Increase stalling speed. Explanation. A forward CG would require the tail of the aircraft to exert more download to keep the nose level. This will increase the wing loading and thus the aircraft would stall at a higher speed.
Question Number. 186. Which statement is true?. Option A. Both Induced drag and profile drag increase with the square of the airspeed. Option B. Profile drag increases with the square of the airspeed. Option C. Induced drag increases with the square of the airspeed.
Correct Answer is. Induced drag increases with the square of the airspeed. Explanation. Profile drag increases with the square of the airspeed but induced drag decreases with the square of the airspeed.
Question Number. 30. Which of the following types of drag increases as the aircraft gains altitude?. Option A. Interference drag. Option B. Parasite drag. Option C. Induced drag.
Correct Answer is. Induced drag. Explanation. As density decreases with altitude, the lift must be compensated by increasing angle of attack. Induced drag increases with angle of attack, therefore induced drag increases with altitude.
Question Number. 182. What happens to the wingtip stagnation point as the AOA increases?. Option A. It moves down and under the leading edge. Option B. It moves up and over the leading edge. Option C. It remains unchanged.
Correct Answer is. It moves down and under the leading edge. Explanation. It moves down and under the leading edge.
Question Number. 28. As the angle of attack decreases, what happens to the centre of pressure?. Option A. It moves rearwards. Option B. Centre of pressure is not affected by angle of attack decrease. Option C. It moves forward.
Correct Answer is. It moves rearwards. Explanation. The centre of pressure moves FORWARDS with an INCREASE in angle of attack. Therefore it moves REARWARDS with a DECREASE in angle of attack.
Question Number. 27. When does the angle of incidence change?. Option A. It never changes. Option B. When the aircraft attitude changes. Option C. When the aircraft is ascending or descending.
Correct Answer is. It never changes. Explanation. The angle of incidence is the angle at which the wing is 'set' into the fuselage. It never changes.
Question Number. 190. Which of the following is incorrect about induced drag?. Option A. It will increase inversely to the square of the airspeed. Option B. It will decrease in proportion to the square of the airspeed. Option C. It will increase when the angle of attack is reduced.
Correct Answer is. It will increase when the angle of attack is reduced. Explanation. Which is Incorrect.
Question Number. 114. Which of the following is true?. Option A. Lift acts at right angles to the relative airflow and weight acts vertically down. Option B. Lift acts at right angles to the wing chord line and weight acts vertically down. Option C. Lift acts at right angles to the relative air flow and weight acts at right angles to the aircraft centre line.
Correct Answer is. Lift acts at right angles to the relative air flow and weight acts vertically down. Explanation. Lift acts at right angles to the relative airflow and weight acts vertically down.
Question Number. 7. Which of the following is true?. Option A. Lift acts at right angles to the relative airflow and weight acts vertically down. Option B. Lift acts at right angles to the wing chord line and weight acts vertically down. Option C. Lift acts at right angles to the relative air flow and weight acts at right angles to the aircraft centre line.
Correct Answer is. Lift acts at right angles to the relative airflow and weight acts vertically down. Explanation. Lift acts at right angles to the relative airflow and weight acts vertically down.
Question Number. 83. Which of the following forces act on an aircraft in level flight?. Option A. Lift, drag, thrust. Option B. Lift, thrust, and weight. Option C. Lift, thrust, weight, and drag.
Correct Answer is. Lift, thrust, weight, and drag. Explanation. Lift, thrust, weight and drag act on an aircraft in level flight.
Question Number. 111. When an aircraft experiences induced drag. Option A. air flows under the wing span wise towards the root and on top of the wing span wise towards the tip. Option B. air flows under the wing span wise towards the tip and on top of the wing span wise towards the root. Option C. Neither a) or b) since induced drag does not cause span wise flow.
Correct Answer is. Neither a) or b) since induced drag does not cause span wise. OR air flows under the wing span wise towards the tip and on top of the wing span wise towards the root. Explanation. Induced drag causes air to flow under the wing span wise towards the tip and on top of the wing span wise towards the root.
Question Number. 56. The amount of thrust produced by a jet engine or a propeller can be calculated using. Option A. Newton's 3rd law. Option B. Newton's 2nd law. Option C. Newton's 1st law.
Correct Answer is. Newton's 2nd law. Explanation. Newton's second law is Force = Mass x Acceleration.
Question Number. 66. The concept of thrust is explained by. Option A. Bernoulli's theorem. Option B. Newton's 3rd law. Option C. Newton's 1st law.
Correct Answer is. Newton's 3rd law. Explanation. Newton's Third Law states 'Every action has an equal and opposite reaction'.
Question Number. 23. For a given aerofoil production lift, whereP = pressure and V = velocity. Option A. P1 is greater than P2, and V1 is less than V2. Option B. P1 is greater than P2, and V1 is greater than V2. Option C. P1 is less than P2 and V1 is greater than V2.
Correct Answer is. P1 is greater than P2, and V1 is less than V2. Explanation. Bernoulli's principle applies.
Question Number. 78. When airflow velocity over an upper cambered surface of an aerofoil decreases, what takes place?. Option A. Pressure decreases, lift increases. Option B. Pressure increases, lift decreases. Option C. Pressure increases, lift increases.
Correct Answer is. Pressure increases, lift decreases. Explanation. When airflow velocity over the upper cambered surface of an aerofoil DECREASES, the pressure increases and thus the lift decreases.
Question Number. 185. Which of the following is true about Profile drag?. Option A. Profile drag = Skin Drag + Form Drag. Option B. Profile drag = skin drag + induced drag. Option C. Profile drag = induced drag + Form drag.
Correct Answer is. Profile drag = Skin Drag + Form Drag. Explanation. Profile drag = Skin Drag + Form Drag.
Question Number. 85. Under the ICAO 'Q' code there are which three settings?. Option A. QEF, QNH, QEN. Option B. QE, QN, QQE. Option C. QFE, QNH, QNE.
Correct Answer is. QFE, QNH, QNE. Explanation. The ICAO 'Q' codes are QFE. QNE, QNH.
Question Number. 187. Which statement is true?. Option A. Rectangular wings stall at the root first. Option B. Both tapered and rectangular wings will stall at the tip first. Option C. Tapered wings stall at the root first.
Correct Answer is. Rectangular wings stall at the root first. Explanation. Rectangular wings stall at the root first.
Question Number. 77. What type of drag, depends on the smoothness of the body, and surface area over which the air flows?. Option A. Form drag. Option B. Parasite drag. Option C. Skin friction drag.
Correct Answer is. Skin friction drag. Explanation. Skin friction drag depends upon the smoothness of the body and the surface area.
Question Number. 20. What is Boundary Layer?. Option A. Separated layer of air forming a boundary at the leading edge. Option B. Sluggish low energy air that sticks to the wing surface and gradually gets faster until it joins the free stream flow of air. Option C. Turbulent air moving from the leading edge to trailing edge.
Correct Answer is. Sluggish low energy air that sticks to the wing surface and gradually gets faster until it joins the free stream flow of air. Explanation. The boundary layer is the layer of air immediately in contact with the aircraft skin which is slowed down by the skin friction.
Question Number. 103. Aspect ratio is given by the formula. Option A. Mean Chord / Span. Option B. Span2 / Area. Option C. Span2 / Mean Chord.
Correct Answer is. Span2 / Area. Explanation. Aspect Ratio is span/mean chord. Multiply top and bottom by span and you get span2/area.
Question Number. 75. Which of the following describes the 'Empennage'?. Option A. Tail section of the aircraft, including fin, rudder, tail plane and elevators. Option B. Nose section of an aircraft, including the cockpit. Option C. The wings, including the ailerons.
Correct Answer is. Tail section of the aircraft, including fin, rudder, tail plane and elevators. Explanation. Empannage' is the whole tail of the aircraft including fin, rudder, tailplane and elevator.
Question Number. 19. What is the definition of Angle of Incidence?. Option A. The angle the underside of the mainplane or tailplane makes with the horizontal. Option B. The angle the underside of the mainplane or tailplane makes with the longitudinal datum line. Option C. The angle the chord of the mainplane or tailplane makes with the horizontal.
Correct Answer is. The angle the chord of the mainplane or tailplane makes with the horizontal. Explanation. Angle of incidence is the 'wing setting angle'. That is the angle of the chord of the mainplane or tailplane with the horizontal - or aircraft centre line when in the rigging position.
Question Number. 183. What does the term 'wing washout' mean?. Option A. The design of the wing that gives the wing tip a lower angle of incidence. Option B. The design of the wing that gives the wing tip a much greater angle of incidence. Option C. The airflow moves toward the end of the wing.
Correct Answer is. The design of the wing that gives the wing tip a lower angle of incidence. Explanation. Wing is twisted such that incidence is lower at the tip.
Question Number. 108. Given 2 wings, the first with a span of 12m and a chord of 2 m. The second has a span of 6m and a chord of 1m. How do their Aspect Ratios compare?. Option A. The first is higher. Option B. They are the same. Option C. The second is higher.
Correct Answer is. They are the same. Explanation. Aspect ratio = Span/Chord.
Question Number. 9. "What happens to air flowing at the speed of sound when it enters a converging duct?." Option A. Velocity increases, pressure and density decreases. Option B. Velocity, pressure and density increase. Option C. Velocity decreases, pressure and density increase.
Correct Answer is. Velocity decreases, pressure and density increase. Explanation. Subsonic air in incompressible, so density does not change. But this is sonic speed, and everything (P and V) change opposite to what they would if it were subsonic air. Density increases, as does pressure, and velocity decreases. See Mechanics of Flight by AC Kermode.
Question Number. 69. As air flows over the upper cambered surface of an aerofoil, what happens to velocity and pressure?. Option A. Velocity increases, pressure increases. Option B. Velocity increases, pressure decreases. Option C. Velocity decreases, pressure decreases.
Correct Answer is. Velocity increases, pressure decreases. Explanation. As air flows over the upper cambered surface of an aerofoil, velcity increases and pressure decreases. This is Bernoulli's effect.
Question Number. 44. With an increase in aircraft weight. Option A. Vmd will be at a higher speed. Option B. Vmd will be at the same speed. Option C. Vmd will be at a lower speed.
Correct Answer is. Vmd will be at a higher speed. Explanation. Sketch the drag curves (drag against speed). Induced drag decreases exponentially with speed. Profile drag increases exponentially with speed. The induced drag is elevated with weight (since it is lift dependant) and so cuts the profile drag further to the right (higher Vmd).
Question Number. 70. What is the force that tends to pull an aircraft down towards the earth?. Option A. Thrust. Option B. Weight. Option C. Drag.
Correct Answer is. Weight. Explanation. Weight tends to pull the aircraft down towards the earth.
Question Number. 193. When is the angle of incidence the same as the angle of attack?. Option A. Never. Option B. In descent. Option C. When relative airflow is parallel to longitudinal axis.
Correct Answer is. When relative airflow is parallel to longitudinal axis. Explanation. NIL.
Question Number. 150. If the C of G is calculated after loading as within limits for take off. Option A. a further calculation is required prior to landing to allow for fuel and oil consumption. Option B. a further calculation is required prior to landing to allow for flap deployment. Option C. no further calculation is required.
Correct Answer is. a further calculation is required prior to landing to allow for fuel and oil consumption. Explanation. If the CG of the fuel is not directly on the empty aircraft CG, the loaded aircraft CG must be calculated twice (with and without fuel).
Question Number. 123. A delta wing has. Option A. a lower stall angle than a straight wing. Option B. a higher stall angle than a straight wing. Option C. the same stall angle than a straight wing.
Correct Answer is. a higher stall angle than a straight wing. Explanation. A delta wing has a much higher stall angle than a normal wing (some as much as 40 degrees).
Question Number. 155. The boundary layer over an aerofoil is. Option A. a layer of air close to the aerofoil which is moving at a velocity less than free stream air. Option B. a layer of turbulent air close to the aerofoil which is moving at a velocity less than free stream air. Option C. a layer of air close to the aerofoil that is stationary.
Correct Answer is. a layer of air close to the aerofoil which is moving at a velocity less than free stream air. Explanation. Boundary layer air consists of turbulent and laminar airflow.
Question Number. 102. An aircraft in straight and level flight is subject to. Option A. a load factor of 1. Option B. a load factor of ½. Option C. zero load factor.
Correct Answer is. a load factor of 1. Explanation. An aircraft in straight and level flight is subject to a load factor of 1 (i.e. 1g).
Question Number. 53. The boundary layer of a body in a moving airstream is. Option A. a layer of air over the surface where the airspeed is changing from free stream speed to zero speed. Option B. a layer of separated flow where the air is turbulent. Option C. a thin layer of air over the surface where the air is stationary.
Correct Answer is. a thin layer of air over the surface where the air is stationary. OR a layer of air over the surface where the airspeed is changing from free stream speed to zero speed. Explanation. The boundary layer is a thin layer of slowed air in contact with the surface of the skin which is slowed by friction. Speed ranging from stationary to free stream speed.
Question Number. 4. When an aircraft experiences induced drag. Option A. air flows under the wing span wise towards the root and on top of the wing span wise towards the tip. Option B. Neither a) or b) since induced drag does not caused by span wise flow. Option C. air flows under the wing span wise towards the tip and on top of the wing span wise towards the root.
Correct Answer is. air flows under the wing span wise towards the tip and on top of the wing span wise towards the root. OR Neither a) or b) since induced drag does not caused by. Explanation. The high pressure under the wing flows around the tip to the low pressure on top of the wing. The resulting vortex is what causes induced drag. Since air is viscous it drags the air underneath the wing towards the tip, and pushes the air on top of the wing towards the root.
Question Number. 39. QFE is. Option A. airfield pressure. Option B. difference between sea level and airfield pressure. Option C. sea level pressure.
Correct Answer is. airfield pressure. Explanation. Q' is the mathematical symbol for pressure. 'FE' stands for Field Elevation. QFE refers to setting airfield pressure so the altimeter indicates zero on the runway.
Question Number. 36. QNH refers to. Option A. quite near horizon. Option B. setting the altimeter to zero. Option C. setting the mean sea level atmospheric pressure so an altimeter reads the aerodrome altitude above mean sea level.
Correct Answer is. altimeter reads the aerodrome altitude above mean sea level. Explanation. Q' is the mathematical symbol for pressure. 'NH' stands for Nautical Height. QNH refers to the setting of actual sea level atmospheric pressure so the altimeter indicates the actual altitude above sea level of the non-standard day.
Question Number. 166. The airflow behind a normal shockwave will. Option A. always be subsonic and in the same direction as the original airflow. Option B. always be supersonic and in the same direction as the original airflow. Option C. always be subsonic and deflected from the direction of the original airflow.
Correct Answer is. always be subsonic and in the same direction as the original airflow. Explanation. The airflow behind a normal shock is subsonic, and in the same direction. It is supersonic behind an oblique shock (and slightly deflected).
Question Number. 45. For a given IAS an increase in altitude will result in. Option A. an increase in induced drag. Option B. no change in the value of induced drag. Option C. an increase in profile drag.
Correct Answer is. an increase in induced drag. Explanation. With a decrease in density the aircraft must fly with a greater angle of attack (CL) to compensate for the loss of lift. Induced drag is dependant upon AOA, therefore induced drag increases with altitude.
Question Number. 165. The lift on a wing is increased with. Option A. an increase in temperature. Option B. an increase in pressure. Option C. an increase in humidity.
Correct Answer is. an increase in pressure. Explanation. Lift depends on density. Increases in humidity and temperature reduce density. Increase in pressure increases density.
Question Number. 92. All the factors that affect the lift produced by an aerofoil are. Option A. angle of attack, velocity, wing area, aerofoil shape, air density. Option B. angle of attack, air temperature, velocity, wing area. Option C. angle of attack, air density, velocity, wing area.
Correct Answer is. angle of attack, velocity, wing area, aerofoil shape, air density. Explanation. Lift formula is CL (includes aerofoil shape and angle of attack) * 1/2 * air density * velocity squared.
Question Number. 71. The angle at which the chord line of the aerofoil is presented to the airflow is known as. Option A. angle of attack. Option B. resultant. Option C. angle of incidence.
Correct Answer is. angle of attack. Explanation. Angle of Attack is the angle at which the chord line of the aerofoil is presented to the airflow.
Question Number. 97. The stalling of an aerofoil is affected by the. Option A. transition speed. Option B. airspeed. Option C. angle of attack.
Correct Answer is. angle of attack. Explanation. The stall position of an aerofoil is determined by its angle of attack only.
Question Number. 26. The 'wing setting angle' is commonly known as. Option A. angle of dihedral. Option B. angle of incidence. Option C. angle of attack.
Correct Answer is. angle of incidence. Explanation. The wing setting angle is commonly known as the 'angle of incidence'.
Question Number. 29. A decrease in pressure over the upper surface of a wing or aerofoil is responsible for. Option A. approximately 2/3 (two thirds) of the lift obtained. Option B. approximately 1/2 (one half) of the lift obtained. Option C. approximately 1/3 (one third) of the lift obtained.
Correct Answer is. approximately 2/3 (two thirds) of the lift obtained. Explanation. Look at a diagram of the lift distributions on the top and bottom surfaces of a wing. 2/3rds of the lift is provided by the top surface.
Question Number. 47. Stall inducers may be fitted to a wing. Option A. at the root to cause the root to stall first. Option B. at the tip to cause the root to stall first. Option C. at the root to cause the tip to stall first.
Correct Answer is. at the root to cause the root to stall first. Explanation. Stall inducers (or stall strips) are placed at the root of the wing to trip up the airflow just before full stall to ensure the wing stalls first at the root (and maintains the aileron authority even with a partially stalled wing).
Question Number. 120. The trailing vortex on a pointed wing (taper ratio = 0) is. Option A. at the tip. Option B. equally all along the wing span. Option C. at the root.
Correct Answer is. at the root. Explanation. The vortex of a pointed wing concentrated at the root of the wing - exactly opposite to straight wings.
Question Number. 31. The layer of air over the surface of an aerofoil which is slower moving, in relation to the rest of the airflow, is known as. Option A. none of the above. Option B. camber layer. Option C. boundary layer.
Correct Answer is. boundary layer. Explanation. The boundary layer is the layer of air in immediate contact with the skin of the aircraft which is slowed down by skin friction.
Question Number. 65. All the lift can be said to act through the. Option A. centre of pressure. Option B. centre of gravity. Option C. normal axis.
Correct Answer is. centre of pressure. Explanation. All the lift is said to act through the centre of pressure.
Question Number. 33. If the C of G is aft of the Centre of Pressure. Option A. when the aircraft yaws the aerodynamic forces acting forward of the Centre of Pressure. Option B. changes in lift produce a pitching moment which acts to increase the change in lift. Option C. when the aircraft sideslips, the C of G causes the nose to turn into the sideslip thus applying a restoring moment.
Correct Answer is. changes in lift produce a pitching moment which acts to increase the change in lift. Explanation. If the C of G is aft of the centre of pressure (not normal, but possible), an increase in lift will pitch the aircraft nose-up, which will increase the lift even further etc. etc.
Question Number. 177. The total drag of an aircraft. Option A. changes with speed. Option B. increases with speed. Option C. increases with the square of speed.
Correct Answer is. changes with speed. Explanation. The graph of TOTAL drag against airspeed is 'U' shaped. c can be the only correct answer.
Question Number. 118. The angle of attack of an aerofoil section is the angle between the. Option A. underside of the wing surface and the mean airflow. Option B. chord line and the relative airflow. Option C. chord line and the centre line of the fuselage.
Correct Answer is. chord line and the relative airflow. Explanation. Angle of attack of an aerofoil is the angle between the chord line and the relative air flow.
Question Number. 109. The C of G moves in flight. The most likely cause of this is. Option A. movement of passengers. Option B. consumption of fuel and oils. Option C. movement of cargo.
Correct Answer is. consumption of fuel and oils. Explanation. Consumption of fuel and oil causes the C of G to move in flight.
Question Number. 151. Helicopter rotor blades create lift by. Option A. pushing the air down. Option B. working like a screw. Option C. creating low pressure above the blades.
Correct Answer is. creating low pressure above the blades. Explanation. A pure aerodynamicist would say all three are correct. But probably a) is technically most correct.
Question Number. 135. Flexure of a rearward swept wing will. Option A. increase the lift and hence increase the flexure. Option B. increase the lift and hence decrease the flexure. Option C. decrease the lift and hence decrease the flexure.
Correct Answer is. decrease the lift and hence decrease the flexure. Explanation. Flexure of a rearward swept wing will decrease the lift (since the wing presents its upper surface to the airflow and the angle of attack reduces) and so the wing flexes back.
Question Number. 164. If the wing loading of an aircraft were reduced the stalling speed would. Option A. increase. Option B. not be affected. Option C. decrease.
Correct Answer is. decrease. Explanation. An increase in wing loading increases the stall speed. And vice versa.
Question Number. 40. For any given speed, a decrease in aircraft weight, the induced drag will. Option A. decrease. Option B. remain the same. Option C. increase.
Correct Answer is. decrease. Explanation. Induced drag is 'lift dependant drag'. Less lift and there will be less induced drag.
Question Number. 24. Low wing loading. Option A. increases stalling speed, landing speed and landing run. Option B. increases lift, stalling speed and maneuverability. Option C. decreases stalling speed, landing speed and landing run.
Correct Answer is. decreases stalling speed, landing speed and landing run. Explanation. Wing loading is aircraft weight divided by wing area, therefore an aircraft with a low wing loading will require less landing speed, less landing run and have a decreased stalling speed.
Question Number. 94. The induced drag of an aircraft. Option A. increases if aspect ratio is increased. Option B. decreases with increasing speed. Option C. increases with increasing speed.
Correct Answer is. decreases with increasing speed. Explanation. Induced drag decreases with increasing speed.
Question Number. 34. The upper part of the wing in comparison to the lower. Option A. develops less lift. Option B. develops the same lift. Option C. develops more lift.
Correct Answer is. develops more lift. Explanation. Look at the lift distribution diagram of an aerofoil and see how approximately 2/3rds of the lift is derived from the top surface.
Question Number. 82. Upward and outward inclination of a mainplane is termed. Option A. dihedral. Option B. sweep. Option C. stagger.
Correct Answer is. dihedral. Explanation. Upward and outward inclination of a mainplane is termed dihedral.
Question Number. 58. Wing loading is calculated by weight. Option A. divided by lift. Option B. divided by gross wing area. Option C. multiplied by gross wing area.
Correct Answer is. divided by gross wing area. Explanation. Wing loading is weight divided by wing area and measured in Newtons per square metre.
Question Number. 173. To produce lift, an aerofoil must be. Option A. symmetrical. Option B. asymmetrical. Option C. either (a) or (b).
Correct Answer is. either (a) or (b). Explanation. A symmetrical wing will produce lift if presented at a suitable positive angle of attack.
Question Number. 145. To produce lift, an aerofoil must be. Option A. asymmetrical. Option B. symmetrical. Option C. either symmetrical or asymmetrical.
Correct Answer is. either symmetrical or asymmetrical. Explanation. To produce lift, the aerofoil can be either symmetrical or asymmetrical.
Question Number. 43. Induced Drag is. Option A. never equal to profile drag. Option B. equal to profile drag at Vmd. Option C. equal to profile drag at stalling angle.
Correct Answer is. equal to profile drag at Vmd. Explanation. Sketch the drag curves (drag against speed). Induced drag decreases exponentially with speed. Profile drag increases exponentially with speed. Vmd (minimum drag speed) is where they meet.
Question Number. 168. Interference drag can be reduced by the use of. Option A. fairings at junctions between fuselage and wings. Option B. high aspect ratio wings. Option C. streamlining.
Correct Answer is. fairings at junctions between fuselage and wings. Explanation. Interference drag occurs as a result of turbulence at wing body joints.
Question Number. 134. The thickness/chord ratio of the wing is also known as. Option A. fineness ratio. Option B. mean chord ratio. Option C. aspect ratio.
Correct Answer is. fineness ratio. Explanation. The thickness/chord ratio of the wing is also known as the fineness ratio. (Technically, thickness/chord ratio = 1/fineness ratio).
Question Number. 89. Airflow over the upper surface of the wing generally. Option A. flows towards the tip. Option B. flows towards the root. Option C. flows straight from leading edge to trailing edge.
Correct Answer is. flows towards the root. Explanation. Due to wing tip vortices there is a general flow of air from tip to root on the top surface, and root to tip on the lower surface.
Question Number. 157. Streamlining will reduce. Option A. induced drag. Option B. skin friction drag. Option C. form drag.
Correct Answer is. form drag. Explanation. Form drag is a function of shape.
Question Number. 126. For a given angle of attack, induced drag is. Option A. greater on a high aspect ratio wing. Option B. greater towards the wing root. Option C. greater on a low aspect ratio wing.
Correct Answer is. greater on a low aspect ratio wing. Explanation. A low aspect ratio wing (short-stubby wing) has a greater induced drag.
Question Number. 41. The amount of lift generated by a wing is. Option A. greatest at the tip. Option B. constant along the span. Option C. greatest at the root.
Correct Answer is. greatest at the root. Explanation. See a diagram of the lift distribution of the wing (viewed from the front) and you will see it is parabolic. The wing tip vortices decrease the lift at the tips.
Question Number. 42. Induced Drag is. Option A. greatest towards the tip and downwash decreases from tip to root. Option B. greatest towards the wing tip and downwash is greatest towards the root. Option C. greatest towards the wing root and downwash is greatest at the tip.
Correct Answer is. greatest towards the tip and downwash decreases from tip to root. Explanation. Induced drag is associated with wingtip vortices. The greater the vortices at the tip, the greater is the induced drag.
Question Number. 169. Gliding angle is the angle between. Option A. ground and the glide path. Option B. aircraft and flight path. Option C. aircraft and airflow.
Correct Answer is. ground and the glide path. Explanation. The greater the L/D angle the less the glide angle is- therefore you can glide further.
Question Number. 105. A high aspect ratio wing. Option A. has a higher stall angle than a low aspect ratio wing. Option B. is stiffer than a low aspect ratio wing. Option C. has less induced drag than a low aspect ratio wing.
Correct Answer is. has less induced drag than a low aspect ratio wing. Explanation. A long slender wing (high aspect ratio) has less induced drag than a short stubby wing.
Question Number. 107. A straight rectangular wing, without any twist, will. Option A. have less angle of attack at the tip. Option B. have greater angle of attack at the tip. Option C. have the same angle of attack at all points along the span.
Correct Answer is. have the same angle of attack at all points along the span. OR have less angle of attack at the tip. Explanation. Due to wingtip vortices, there is more downwash at the tip, and therefore there is less angle of attack at the tip.
Question Number. 167. Induced drag can be reduced by the use of. Option A. streamlining. Option B. high aspect ratio wings. Option C. fairings at junctions between fuselage and wings.
Correct Answer is. high aspect ratio wings. Explanation. High aspect ratio wings have low induced drag (IE a glider wing).
Question Number. 16. A high aspect ratio wing will give. Option A. high profile and low induced drag. Option B. low profile and high induced drag. Option C. low profile and low induced drag.
Correct Answer is. high profile and low induced drag. Explanation. A high aspect ratio has a lower induced drag (due to less wing tip effect) and a higher frontal area therefore greater profile drag.
Question Number. 64. With the ailerons away from the neutral, induced drag is. Option A. higher on the lower wing plus profile drag increases. Option B. unchanged but profile drag is higher. Option C. higher on the upper wing plus profile drag increases.
Correct Answer is. higher on the upper wing plus profile drag increases. Explanation. Induced drag is 'lift dependant drag'. The upper wing has more lift and hence more induced drag. It also has more profile drag due to the aileron's protrusion into the airflow.
Question Number. 156. On a swept wing aircraft, the fineness ratio of an aerofoil is. Option A. highest at the root. Option B. equal throughout the span. Option C. highest at the tip.
Correct Answer is. highest at the tip. Explanation. Fineness ratio (chord/thickness) is greatest at the tip. Fineness ratio is the inverse of thickness/chord ratio. Some textbooks differ on the definition of 'fineness ratio' but most state FR = chord/thickness. Quote A&P Mechanics Airframe Handbook Page 32 'If a wing has a high fineness ratio, it is a very thin wing. A thick wing has low fineness ratio'.
Question Number. 176. Airflow at sub-sonic speed is taken to be. Option A. incompressible. Option B. compressible. Option C. either (a) or (b) depending on altitude.
Correct Answer is. incompressible. Explanation. NIL.
Question Number. 142. Airflow at subsonic speed is taken to be. Option A. compressible. Option B. either a or b depending on altitude. Option C. incompressible.
Correct Answer is. incompressible. Explanation. Subsonic airflow is always considered to be incompressible.
Question Number. 91. If the density of the air is increased, the lift will. Option A. remain the same. Option B. increase. Option C. decrease.
Correct Answer is. increase. Explanation. See the formula for lift. Lift is directly proportional to air density.
Question Number. 115. The airflow over the upper surface of a cambered wing. Option A. increases in velocity and reduces in pressure. Option B. increases in velocity and pressure. Option C. reduces in velocity and increases in pressure.
Correct Answer is. increases in velocity and reduces in pressure. Explanation. Airflow flowing over the upper surface of an aerofoil increases in velocity and decreases in pressure.
Question Number. 124. The airflow over the upper surface of a cambered wing. Option A. reduces in velocity and increases in pressure. Option B. increases in velocity and reduces in pressure. Option C. increases in velocity and pressure.
Correct Answer is. increases in velocity and reduces in pressure. Explanation. Airflow over the upper surface of a cambered surface of the wing increases in velocity and decreases in pressure.
Question Number. 2. Lift on a delta wing aircraft. Option A. increases with an increased angle of incidence (angle of attack). Option B. does not change with a change in angle of incidence (angle of attack). Option C. decreases with an increase in angle of incidence (angle of attack).
Correct Answer is. increases with an increased angle of incidence (angle of attack). OR does not change with a change in angle of incidence (angle of. Explanation. This question is much easier than it looks at first read. All wing types (straight, swept, delta etc.) increase lift with an increase in angle of attack (up to the stall angle).
Question Number. 88. Induced drag. Option A. increases with increase in aircraft weight. Option B. increases with an increase in speed. Option C. reduces with an increase in angle of attack.
Correct Answer is. increases with increase in aircraft weight. Explanation. Induced drag increase with aircraft weight because it is 'lift dependant drag'.
Question Number. 95. As the speed of an aircraft increases, the profile drag. Option A. decreases at first then increase. Option B. increases. Option C. decreases.
Correct Answer is. increases. Explanation. Profile drag increases with increasing speed.
Question Number. 170. Propeller Solidity can be increased by. Option A. increasing the number of blades. Option B. decreasing the length of the blades. Option C. increasing the blade angle.
Correct Answer is. increasing the number of blades. Explanation. A C Kermode Mechanics of Flight CH 4 Page 138 shows methods of increasing solidity.
Question Number. 74. Wing tip vortices create a type of drag known as. Option A. form drag. Option B. profile drag. Option C. induced drag.
Correct Answer is. induced drag. Explanation. Induced drag is associated with wingtip vortices.
Question Number. 59. Induced drag is. Option A. nothing to do with speed. Option B. proportional to speed. Option C. inversely proportional to the square of speed.
Correct Answer is. inversely proportional to the square of speed. Explanation. Induced drag is inversely proportional to the square of the speed - i.e. it reduces with the square of the speed.
Question Number. 18. The relationship between induced drag and airspeed is, induced drag is. Option A. directly proportional to the square of the speed. Option B. directly proportional to speed. Option C. inversely proportional to the square of the speed.
Correct Answer is. inversely proportional to the square of the speed. Explanation. Induced drag decreases proportionally with the square of the speed.
Question Number. 128. Induced drag. Option A. is equal to the profile drag at Vmd. Option B. is equal to the profile drag at the stalling speed. Option C. is never equal to the profile drag.
Correct Answer is. is equal to the profile drag at Vmd. Explanation. Induced drag is equal to profile drag at Vmd.
Question Number. 137. Stall commencing at the root is preferred because. Option A. it provides the pilot with a warning of complete loss of lift. Option B. the ailerons become ineffective. Option C. it will cause the aircraft to pitch nose up.
Correct Answer is. it provides the pilot with a warning of complete loss of lift. Explanation. Stall commencing at the root causes turbulent air to hit the tailplane. The resulting 'buffet' warns the pilot just before complete stall.
Question Number. 152. The span wise component of the airflow is. Option A. greater at higher speeds. Option B. unaffected by speed. Option C. less at higher speeds.
Correct Answer is. less at higher speeds. Explanation. The tip vortices are less at high speed (due to lower AOA at high speed). The tip vortices cause the span wise flow.
Question Number. 57. An engine which produces an efflux of high speed will be. Option A. less efficient. Option B. more efficient. Option C. speed of efflux has no affect on the engine efficiency.
Correct Answer is. less efficient. Explanation. A pure turbojet accelerates a low mass of air at a high rate and is less efficient than a turbo fan or turbo prop. This is because the wasted energy is 1/2mV2 of the jet efflux.
Question Number. 129. 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. Option A. more lift. Option B. less lift. Option C. the same lift.
Correct Answer is. less lift. Explanation. A delta wing aircraft at any given angle of attack and speed will produce less lift than any other type of wing.
Question Number. 54. A laminar boundary layer will produce. Option A. more skin friction drag than a turbulent one. Option B. the same skin friction drag as a turbulent one. Option C. less skin friction drag than a turbulent one.
Correct Answer is. less skin friction drag than a turbulent one. Explanation. Skin friction drag is greater in a turbulent boundary layer than in a laminar boundary layer.
Question Number. 121. The lift curve for a delta wing is. Option A. more steep than that of a high aspect ratio wing. Option B. less steep than that of a high aspect ratio wing. Option C. the same as that of a high aspect ratio wing.
Correct Answer is. less steep than that of a high aspect ratio wing. Explanation. A delta wing produces less lift for any given angle of attack than any other type of wing.
Question Number. 140. The Rams Horn Vortex on a forward swept wing will be. Option A. more than a rearward swept wing. Option B. less than a rearward swept wing. Option C. the same as a rearward swept wing.
Correct Answer is. less than a rearward swept wing. Explanation. A forward swept wing does not suffer from the Rams Horn Vortex.
Question Number. 127. In straight and level flight, the angle of attack of a swept wing is. Option A. less than the aircraft angle to the horizontal. Option B. more than the aircraft angle to the horizontal. Option C. the same as the aircraft angle to the horizontal.
Correct Answer is. less than the aircraft angle to the horizontal. Explanation. Since the 'effective' velocity vector over a swept wing is not parallel with the forward direction of the aircraft, a change in pitch of the aircraft has lesser effect upon the AOA of the wing.
Question Number. 125. The speed of air over a swept wing which contributes to the lift is. Option A. less than the aircraft speed. Option B. the same as the aircraft speed. Option C. more than the aircraft speed.
Correct Answer is. less than the aircraft speed. Explanation. If aircraft speed is V, speed of airflow over wing which contributes to lift is Vcos(sweepangle). Cos(sweepangle) < 1. See AC Kermode, Mechanics of Flight (10th edition). Pg 359 Fig 11.16.
Question Number. 79. When an aircraft stalls. Option A. lift increases and drag decreases. Option B. lift and drag increase. Option C. lift decreases and drag increases.
Correct Answer is. lift decreases and drag increases. Explanation. When an aircraft stalls the drag increases and the lift decreases.
Question Number. 17. Aerofoil efficiency is defined by. Option A. lift over drag. Option B. lift over weight. Option C. drag over lift.
Correct Answer is. lift over drag. Explanation. At plus 4degrees AOA the lift weight ratio is greatest. This is the optimum AOA therefore the wing is at its most efficient when lift is greatest and drag is at a minimum.
Question Number. 162. During a glide the following forces act on an aircraft. Option A. lift and weight only. Option B. lift, drag, weight. Option C. lift, weight, thrust.
Correct Answer is. lift, drag, weight. Explanation. No thrust in a glide. The weight provides the forward motion.
Question Number. 136. A High Aspect Ratio wing is a wing with. Option A. short span, long chord. Option B. long span, long chord. Option C. long span, short chord.
Correct Answer is. long span, short chord. Explanation. Aspect ratio is the ratio of span to chord.
Question Number. 61. The term pitch-up is due to. Option A. compressibility effect. Option B. ground effect. Option C. longitudinal instability.
Correct Answer is. longitudinal instability. Explanation. Pitch-up' is a longitudinal instability. It is caused by wingtip stall on swept wings, resulting ina drop of the tail.
Question Number. 11. Vapour trails from the wingtips of an aircraft in flight are caused by. Option A. low pressure above the wing and high pressure below the wing causing vortices. Option B. low pressure above the wing and high pressure below the wing causing a temperature rise. Option C. high pressure above the wing and low pressure below the wing causing vortices.
Correct Answer is. low pressure above the wing and high pressure below the wing causing vortices. Explanation. Vapour trails are caused by wing tip vortices which are caused by low pressure above the wing and high pressure below the wing.
Question Number. 179. Induced drag is ________ at root. Option A. lowest. Option B. greatest. Option C. neutral.
Correct Answer is. lowest. Explanation. NIL.
Question Number. 174. If fluid flow through a venturi is said to be incompressible, the speed of the flow increases at the throat to. Option A. allow for a reduction in static pressure. Option B. allow for an increase in static pressure. Option C. maintain a constant volume flow rate.
Correct Answer is. maintain a constant volume flow rate. Explanation. Continuity of flow principle.
Question Number. 144. If fluid flow through a venturi is said to be incompressible, the speed of the flow increases at the throat to. Option A. allow for a reduction in static pressure. Option B. maintain a constant volume flow rate. Option C. allow for an increase in static pressure.
Correct Answer is. maintain a constant volume flow rate. Explanation. Volume flow rate is constant at all parts of the flow (if fluid in incompressible) regardless of cross sectional area.
Question Number. 87. Weight is equal to. Option A. mass * acceleration. Option B. mass * gravity. Option C. volume * gravity.
Correct Answer is. mass * gravity. Explanation. Weight = mass * gravity in straight and level flight. In a manoeuvre, additional accelerations are present, which are sometimes considered to increase weight. The question can therefore be answered in two ways.
Question Number. 138. An aircraft flying in 'ground effect' will produce. Option A. the same lift as a similar aircraft outside of ground effect. Option B. less lift than a similar aircraft outside of ground effect. Option C. more lift than a similar aircraft outside of ground effect.
Correct Answer is. more lift than a similar aircraft outside of ground effect. Explanation. An aircraft flying in ground effect will have more lift than an aircraft not flying in ground effect (which is why seagulls glide close to the water surface).
Question Number. 62. In a steady climb at a steady IAS, the TAS is. Option A. more than IAS. Option B. the same. Option C. less than IAS.
Correct Answer is. more than IAS. Explanation. IAS = TAS x square root of sigma. Sigma is the ratio of density at altitude to density at sea- level. Sigma is always less than 1.
Question Number. 171. Lift is generated by a wing. Option A. mostly on the bottom surface. Option B. mostly on the top surface. Option C. equally on the top and bottom surfaces.
Correct Answer is. mostly on the top surface. Explanation. 2/3 of lift is produced by the top surface.
Question Number. 25. As a general rule, if the aerodynamic angle of incidence (angle of attack) of an aerofoil is slightly increased, the centre of pressure will. Option A. move towards the tip. Option B. move forward towards the leading edge. Option C. never move.
Correct Answer is. move forward towards the leading edge. Explanation. As the angle of attack increases the centre of pressure moves towards the leading edge.
Question Number. 10. As the angle of attack of an airfoil increases the centre of pressure. Option A. remains stationary. Option B. moves aft. Option C. moves forward.
Correct Answer is. moves forward. Explanation. As the angle of attack of the aerofoil increases, the centre of pressure moves forward.
Question Number. 5. At stall, the wingtip stagnation point. Option A. doesn't move. Option B. moves toward the lower surface of the wing. Option C. moves toward the upper surface of the wing.
Correct Answer is. moves toward the lower surface of the wing. Explanation. At stall the angle of attack is high (all along the wing) and the stagnation point moves towards the lower surface of the wing.
Question Number. 60. As the angle of attack increases the stagnation point. Option A. moves towards the upper surface. Option B. does not move. Option C. moves towards the lower surface.
Correct Answer is. moves towards the lower surface. Explanation. The stagnation point is the stationary air at the leading edge of the wing. As the angle of attack increases the stagnation point moves towards the lower surface.
Question Number. 1. An aircraft is travelling at a speed of 720 nautical miles per hour. To calculate speed in MPH you. Option A. divide by 0.83. Option B. multipy by 0.83. Option C. multiply by 1.15.
Correct Answer is. multiply by 1.15. Explanation. 1nmph = 1.15mph 1mph = 0.83nmph.
Question Number. 112. An aeroplane wing is designed to produce lift resulting from relatively. Option A. positive air pressure below and above the wing's surface. Option B. positive air pressure below the wing's surface an negative air pressure above the wing's surface. Option C. negative air pressure below the wing's surface and positive air pressure above the wing's surface. OR negative air pressure below the wing's surface and positive air.
Correct Answer is. negative air pressure below the wing's surface and positive air. Explanation. The wing is designed to produce lift resulting from relatively positive air pressure below the wing surface and negative air pressure above the wing surface.
Question Number. 141. For a cambered wing section the zero lift angle of attack will be. Option A. 4 degrees. Option B. zero. Option C. negative.
Correct Answer is. negative. Explanation. A non symmetrical wing will produce some lift at zero degrees. Therefore it must have a negative angle of attack to produce zero lift.
Question Number. 148. The angle of attack is. Option A. related to angle of incidence. Option B. always kept below 15 degrees. Option C. not related to the angle of incidence.
Correct Answer is. not related to the angle of incidence. Explanation. See definitions of angle of attack and angle of incidence.
Question Number. 149. The difference between the mean camber line and the chord line of an aerofoil is. Option A. neither are straight. Option B. they both may be curved. Option C. one is always straight and the other may be straight.
Correct Answer is. one is always straight and the other may be straight. Explanation. See the definitions of mean camber and chord line.
Question Number. 13. The angle of incidence of a wing is an angle formed by lines. Option A. parallel to the chord line and longitudinal axis. Option B. parallel to the chord line and the vertical axis. Option C. parallel to the chord line and the lateral axis.
Correct Answer is. parallel to the chord line and longitudinal axis. Explanation. The angle of incidence is the angle between the chord line and the longitudinal axis.
Question Number. 8. The vertical fin of a single engined aircraft is. Option A. parallel with the longitudinal axis but not the vertical axis. Option B. parallel with both the longitudinal axis and vertical axis. Option C. parallel with the vertical axis but not the longitudinal axis.
Correct Answer is. parallel with both the longitudinal axis and vertical axis. OR parallel with the vertical axis but not the longitudinal axis. Explanation. Single engined aircraft fin is offset to left to counter torque...i.e. chord of fin is at an angle to.longitudinal axis.
Question Number. 133. If a swept wing stalls at the tips first, the aircraft will. Option A. pitch nose up. Option B. roll. Option C. pitch nose down.
Correct Answer is. pitch nose up. Explanation. Since the tips are behind the Centre of Gravity, losing the lift at the tips will cause the nose to rise.
Question Number. 117. An aeroplane wing is designed to produce lift resulting from relatively. Option A. positive air pressure below the wing's surface and negative air pressure above the wing's surface. Option B. negative air pressure below the wing's surface and positive air pressure above the wing's surface. Option C. positive air pressure below and above the wing's surface.
Correct Answer is. positive air pressure below and above the wing's surface. Explanation. The wing is designed to produce lift resulting from relatively positive air pressure below the wing surface and negative air pressure above the wing surface.".
Question Number. 132. With increased speed in level flight. Option A. induced drag increases. Option B. profile drag increases. Option C. profile drag remains constant.
Correct Answer is. profile drag increases. Explanation. Profile drag increases with speed, induced drag decreases with speed.
Question Number. 116. With increased speed in level flight. Option A. profile drag increases. Option B. induced drag increases. Option C. profile drag remains constant.
Correct Answer is. profile drag increases. Explanation. With increased speed in level flight, the profile drag increases and the induced drag decreases.
Question Number. 180. Profile drag is _______ to speed. Option A. neutral. Option B. inversely proportional. Option C. proportional.
Correct Answer is. proportional. Explanation. NIL.
Question Number. 90. With an increase in aspect ratio for a given IAS, induced drag will. Option A. reduce. Option B. remain constant. Option C. increase.
Correct Answer is. reduce. Explanation. A long slender wing (high aspect ratio) has a low induced drag.
Question Number. 153. A wing fence. Option A. acts as a lift dumping device. Option B. reduces span wise flow on a swept wing thus reducing induced drag. Option C. increases lateral control.
Correct Answer is. reduces span wise flow on a swept wing thus reducing induced drag. Explanation. A wing fence reduces span wise flow. Refer : Barnard and Phillpott Page 78.
Question Number. 106. Induced downwash. Option A. reduces the effective angle of attack of the wing. Option B. increases the effective angle of attack of the wing. Option C. has no effect on the angle of attack of the wing.
Correct Answer is. reduces the effective angle of attack of the wing. Explanation. Induced downwash reduces the effective angle of attack of the wing.
Question Number. 68. Induced drag. Option A. is caused by skin friction. Option B. is associated with the lift generated by an aerofoil. Option C. results from disturbed airflow in the region of mainplane. OR is associated with the lift generated by an aerofoil.
Correct Answer is. results from disturbed airflow in the region of mainplane attachments. Explanation. Induced drag is often called 'lift dependant drag' because it increases with increasing lift (due to increased AOA).
Question Number. 22. "A decrease in incidence toward the wing tip may be provided to." Option A. prevent adverse yaw in a turn. Option B. retain lateral control effectiveness at high angles of attack. Option C. prevent span wise flow in maneuvers.
Correct Answer is. retain lateral control effectiveness at high angles of attack. Explanation. A decrease in incidence towards the wingtip (known as washout) causes the wing root to stall before the wing tip. So, even after the wing roots have stalled, the wing tips are still flying and full aileron control is provided.
Question Number. 84. With reference to altimeters, QFE is. Option A. the manufacturers registered name. Option B. quite fine equipment. Option C. setting aerodrome atmospheric pressure so that an altimeter reads zero on landing and take off.
Correct Answer is. setting aerodrome atmospheric pressure so that an altimeter reads zero on landing and take off. Explanation. Q is the mathematical symbol for pressure. FE stands for Field Elevation. QFE refers to setting the altimeter to aerodrome atmospheric pressure so the altimeter reads zero on landing and takeoff.
Question Number. 37. QNE refers to. Option A. setting the mean sea level atmospheric pressure in accordance with ICAO standard atmosphere i.e. 1013 millibars. Option B. Setting an altimeter to read aerodrome altitude above sea level. Option C. quite new equipment.
Correct Answer is. setting the mean sea level atmospheric pressure in accordance with ICAO standard atmosphere i.e. 1013 millibars. Explanation. Q' is the mathematical symbol for pressure. 'NE' stands for Nautical Elevation. QNE refers to the setting of the standard sea level atmospheric pressure (i.e. 1013mb) so the altimeter indicates the elevation above mean sea level. (Although it is not the 'true' elevation, if it is not a standard day).
Question Number. 181. A shock stall occurs at. Option A. large angles of attack. Option B. small angles of attack. Option C. equally both large and small angles of attack.
Correct Answer is. small angles of attack. Explanation. An arguable point. Shock stall is due to shock induced separation which can occur at any angle of attack, but it would be difficult to achieve the high speed necessary with a high angle of attack.
Question Number. 38. An aspect ratio of 8 : 1 would mean. Option A. span 64, mean chord 8. Option B. mean chord 64, span 8. Option C. span squared 64, chord 8.
Correct Answer is. span 64, mean chord 8. Explanation. Aspect Ratio is the ratio of the span to the chord.
Question Number. 159. Ice formed on the leading edge will cause the aircraft to. Option A. stall at a higher speed. Option B. stall at a lower speed. Option C. stall at the same stall speed and AOA.
Correct Answer is. stall at a higher speed. Explanation. Ice change the wing section shape and hence lift (CL) is less and stall speed is greater.
Question Number. 63. An untapered straight wing will. Option A. have no yaw effect in banking. Option B. stall at the root first. Option C. have no change in induced drag in the bank.
Correct Answer is. stall at the root first. Explanation. The straight wing will always stall at the root first. This is the desired stall characteristic.
Question Number. 110. A straight rectangular wing, without any twist, will. Option A. stall equally along the span of the wing. Option B. stall first at the tip. Option C. stall first at the root.
Correct Answer is. stall first at the root. Explanation. A straight rectangular wing will stall first at the root. This is because the effective angle of attack is reduced at the tips because of the greater downwash at the tips.
Question Number. 130. The stagnation point is. Option A. static pressure minus dynamic pressure. Option B. dynamic pressure only. Option C. static pressure plus dynamic pressure.
Correct Answer is. static pressure plus dynamic pressure. Explanation. At stagnation, the pressure is total (static plus dynamic).
Question Number. 46. As the angle of attack of a wing is increased in level flight. Option A. the C of G moves aft and the CofP forward. Option B. the CofP and transition point move forward. Option C. the CofP moves forward and the stagnation point aft over the upper surface.
Correct Answer is. the CofP and transition point move forward. OR the CofP moves forward and the stagnation point aft over the. Explanation. As AOA increases in level flight, CofP moves forward and the Transition Point (the point at which the laminar flow breaks away and forms into turbulent flow) also moves forward.
Question Number. 96. The stagnation point on an aerofoil is the point where. Option A. the boundary layer changes from laminar to turbulent. Option B. the suction pressure reaches a maximum. Option C. the airflow is brought completely to rest.
Correct Answer is. the airflow is brought completely to rest. Explanation. The stagnation point on the aerofoil is the point where the airflow is brought completely to rest on the leading edge.
Question Number. 6. The rigging angle of incidence of an elevator is. Option A. the angle between the bottom surface of the elevator and the longitudinal datum. Option B. the angle between the bottom surface of the elevator and the horizontal in the rigging position. Option C. the angle between the mean chord line and the horizontal in the rigging position.
Correct Answer is. the angle between the mean chord line and the horizontal in the rigging position. Explanation. The angle of incidence of any surface is measured from the mean chord line.
Question Number. 172. Lift is dependent on. Option A. the area of the wing, the density of the fluid medium and the square of the velocity. Option B. the net area of the wing, the density of the fluid medium and the velocity. Option C. the frontal area of the wing, the density of the fluid medium and the velocity. Correct Answer is. the area of the wing, the density of the fluid medium and the square of the velocity.
Correct Answer is. the area of the wing, the density of the fluid medium and the square of the velocity. Explanation. Lift = Lift Coefficient x 1/2 x density x velocity2 x wing area (Lift formula).
Question Number. 146. Lift is dependent on. Option A. the net area of the wing ,the density of the fluid medium and the velocity. Option B. the area of the wing, the density of the fluid medium, and the square of the velocity. Option C. the frontal area of the wing, the density of the fluid medium and the velocity.
Correct Answer is. the area of the wing, the density of the fluid medium, and the square of the velocity. Explanation. See the formula for lift.
Question Number. 52. The transition point on a wing is the point where. Option A. the boundary layer flow changes from laminar to turbulent. Option B. the flow divides to pass above and below the wing. Option C. the flow separates from the wing surface.
Correct Answer is. the boundary layer flow changes from laminar to turbulent. Explanation. The transition point is a point on the surface of the wing where the boundary layer changes from laminar to turbulent.
Question Number. 12. The chord line of a wing is a line that runs from. Option A. the centre of the leading edge of the wing to the trailing edge. Option B. half way between the upper and lower surface of the wing. Option C. one wing tip to the other wing tip.
Correct Answer is. the centre of the leading edge of the wing to the trailing edge. Explanation. The chord line is a STRAIGHT line which goes from the leading edge of the wing to the trailing.
Question Number. 72. The imaginary straight line which passes through an aerofoil section from leading edge to trailing edge is called. Option A. the chord line. Option B. the direction of relative airflow. Option C. centre of pressure.
Correct Answer is. the chord line. Explanation. The Chord Line is the imaginary straight line which passes through the aerofoil from leading edge to trailing edge.
Question Number. 67. The camber of an aerofoil section is. Option A. the angle which the aerofoil makes with the relative airflow. Option B. the curvature of the median line of the aerofoil. Option C. the angle of incidence towards the tip of a wing.
Correct Answer is. the curvature of the median line of the aerofoil. Explanation. Aerofoil camber is the curvature of the median line of the aerofoil.
Question Number. 49. A high aspect ratio wing has a. Option A. increased induced drag. Option B. decreased skin friction drag. Option C. decreased induced drag.
Correct Answer is. the highest lift/drag ratio is produced. Explanation. Induced drag decreases with increasing aspect ratio. (However, skin friction drag also reduces with an increased chord length due to thickening of the boundary layer - but this is less significant.).
Question Number. 48. The optimum angle of attack of an aerofoil is the angle at which. Option A. the aerofoil produces maximum lift. Option B. the aerofoil produces zero lift. Option C. the highest lift/drag ratio is produced.
Correct Answer is. the highest lift/drag ratio is produced. Explanation. The optimum angle of attack is the angle at which the highest lift/drag ratio is produced.
Question Number. 15. Compressibility effect is. Option A. drag associated with the form of an aircraft. Option B. the increase in total drag of an aerofoil in transonic flight due to the formation of shock waves. Option C. drag associated with the friction of the air over the surface of the aircraft.
Correct Answer is. the increase in total drag of an aerofoil in transonic flight due to the formation of shock waves. Explanation. Compressibility effect is associated with an increase in drag during the transonic flight stage.
Question Number. 122. An increase in the speed at which an aerofoil passes through the air increases lift because. Option A. the increased speed of the airflow creates a greater pressure differential between the upper and lower surfaces. Option B. the increased speed of the airflow creates a lesser pressure differential between the upper and lower surfaces. Option C. the increased velocity of the relative wind increases the angle of attack.
Correct Answer is. the increased velocity of the relative wind increases the angle. OR the increased speed of the airflow creates a greater pressure differential between the upper and lower surfaces. Explanation. Increasing the speed of an aerofoil increases the pressure differential between the upper and lower surface.
Question Number. 3. The CofP is the point where. Option A. the lift can be said to act. Option B. the three axis of rotation meet. Option C. all the forces on an aircraft act.
Correct Answer is. the lift can be said to act. Explanation. NIL.
Question Number. 80. Wing loading is. Option A. the maximum all up weight multiplied by the total wing area. Option B. the maximum all up weight divided by the total wing area. Option C. the ratio of the all up weight of the aircraft to its basic weight.
Correct Answer is. the ratio of the all up weight of the aircraft to its basic weight. OR the maximum all up weight divided by the total wing area. Explanation. Wing Loading is weight divided by wing area. Measured in Newtons per Square Metre.
Question Number. 104. An aspect ratio of 8 means. Option A. the mean chord is 8 times the span. Option B. the span is 8 times the mean chord. Option C. the area is 8 times the span.
Correct Answer is. the span is 8 times the mean chord. Explanation. An Aspect Ratio of 8 means the span is 8 times the chord.
Question Number. 163. If an aileron is moved downward. Option A. the stalling angle of that wing is increased. Option B. the stalling angle is not affected but the stalling speed is decreased. Option C. the stalling angle of that wing is decreased.
Correct Answer is. the stalling angle of that wing is decreased. Explanation. The aileron increases the 'local' AOA and provides a greater camber. Both will cause the stalling angle of the wing to decrease.
Question Number. 100. Forward motion of a glider is provided by. Option A. the weight. Option B. the drag. Option C. the engine.
Correct Answer is. the weight. Explanation. The weight provides forward motion of a glider.
Question Number. 81. An aircraft wing with an aspect ration of 6 : 1 is proportional so that. Option A. the wing area is six times the span. Option B. the mean chord is six times the thickness. Option C. the wing span is six times the mean chord.
Correct Answer is. the wing span is six times the mean chord. Explanation. If aspect ratio is 6 : 1 the wing span is 6 times the mean chord.
Question Number. 55. The boundary layer is. Option A. thickest at the leading edge. Option B. thickest at the trailing edge. Option C. constant thickness from leading to trailing edges.
Correct Answer is. thickest at the trailing edge. Explanation. The boundary layer is thickest at the trailing edge.
Question Number. 93. A wing section suitable for high speed would be. Option A. thin with high camber. Option B. thick with high camber. Option C. thin with little or no camber.
Correct Answer is. thin with little or no camber. Explanation. A high speed wing is thin with little camber.
Question Number. 119. A swept wing tends to stall first at the. Option A. centre section. Option B. root. Option C. tip.
Correct Answer is. tip. Explanation. A swept wing tends to stall first at the tip.
Question Number. 131. On a swept wing aircraft, due to the adverse pressure gradient, the boundary layer on the upper surface of the wing tends to flow. Option A. towards the root. Option B. towards the tip. Option C. directly from leading edge to trailing edge.
Correct Answer is. towards the tip. Explanation. Due to adverse pressure gradient on a swept wing, the boundary layer slides towards the tip and thickens at the tip. This is why swept wings stall first at the tips.
Question Number. 184. The point at which airflow ceases to be laminar and becomes turbulent is the. Option A. boundary point. Option B. transition point. Option C. separation point.
Correct Answer is. transition point. Explanation. transition point.
Question Number. 98. The most fuel efficient of the following types of engine is the. Option A. turbo-jet engine. Option B. turbo-fan engine. Option C. rocket.
Correct Answer is. turbo-fan engine. Explanation. The turbo fan is the most fuel efficient engine.
Question Number. 99. The quietest of the following types of engine is the. Option A. turbo-jet engine. Option B. rocket. Option C. turbo-fan engine.
Correct Answer is. turbo-fan engine. Explanation. The turbo fan is the quietest engine.
Question Number. 50. Minimum total drag of an aircraft occurs. Option A. when induced drag is least. Option B. at the stalling speed. Option C. when profile drag equals induced drag.
Correct Answer is. when profile drag equals induced drag. Explanation. Sketch the drag curves (drag against speed). Induced drag decreases exponentially with speed. Profile drag increases exponentially with speed. Vmd (minimum drag speed) is where they meet.
Question Number. 51. If the weight of an aircraft is increased, the induced drag at a given speed. Option A. will increase. Option B. will decrease. Option C. will remain the same.
Correct Answer is. will increase. Explanation. If weight is increased, for a given speed the aircraft must fly at a greater angle of attack (CL). Induced drag increases with increased AOA.
Question Number. 192. If the angle of attack is zero, but lift is produced, the. Option A. wing is symmetrical. Option B. wing is cambered. Option C. wing has positive angle of incidence.
Correct Answer is. wing is cambered. Explanation. NIL.
Question Number. 113. Aspect ratio of a wing is defined as the ratio of the. Option A. wingspan to the mean chord. Option B. wingspan to the wing root. Option C. square of the chord to the wingspan.
Correct Answer is. wingspan to the mean chord. Explanation. Aspect ratio is defined as the ratio of the wing span to mean chord.
Question Number. 143. Bernoulli's equation shows that. Option A. at constant velocity the kinetic energy of the air changes with a change of height. Option B. with a change in velocity at constant height the static pressure will change. Option C. with a change in speed at constant height both kinetic and potential energies change.
Correct Answer is. with a change in velocity at constant height the static pressure will change. Explanation. Bernoulli's theorem states that if velocity increases, the static pressure decreases, and vice versa.
Question Number. 175. Bernoulli's equation shows that. Option A. at constant velocity the total energy of the air changes with a change in height. Option B. with a change in speed at constant height both kinetic and potential energies change. Option C. with a change in velocity at constant height the static pressure will change.
Correct Answer is. with a change in velocity at constant height the static pressure will change. Explanation. Bernoulli's theorem states that if velocity increases, the static pressure decreases, and vice versa.
