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SELF-ASSESSMENT EXERCISE 8 181

Self-Assessment Exercise 8

Q8.1 One of the disadvantages of a swept wing is it’s stalling characteristics. At the stall
(i). . . . . . . . . . . . . . occurs first, which produces (ii). . . . . . . . . . .
(a) (i) wing root stall; (ii) a rolling moment
(b) (i) tip stall; (ii) a nose-down moment
(c) (i) leading edge stall; (ii) a nose-down moment
(d) (i) tip stall; (ii) a pitch-up moment
Q8.2 For any given configuration the stick shaker is activated when the IAS is:
(a) 1.3 Vs
(b) 1.12 Vs
(c) Greater than Vs
(d) 1.2 Vs
Q8.3 An aeroplane in level flight has a stalling speed of 100 kt. In a level turn with a load factor of 1.5
the stalling speed is:
(a) 150 kt
(b) 122 kt
(c) 141 kt
(d) 82 kt
Q8.4 Compared with level flight prior to the stall, the lift (i) and the drag (ii) at the stall change as
follows:
(a) (i) increases; (ii) decreases
(b) (i) decreases; (ii) increases
(c) (i) decreases; (ii) decreases
(d) (i) increases; (ii) increases
Q8.5 Which of the following statements regarding the stalling speed is correct?
(a) The stalling speed is decreased with a smaller angle of sweep.
(b) The stalling speed is increased with a smaller angle of sweep
(c) The stalling speed is decreased with T-tail.
(d) The stalling speed is decreased with increased anhedral.
Q8.6 The critical angle of attack:
(a) decreases as the CG moves aft
(b) alters with an increase of gross mass
(c) remains the same for all masses
(d) increases as the CG moves forward
Q8.7 Which of the following design features is most likely to cause an aeroplane to superstall?
(a) A T-tail.
(b) A canard wing.
(c) Swept wings.
(d) A low horizontal tail.
Q8.8 The stalling speed IAS changes in accordance with the following factors:
(a) It increases in a turn, with increased mass and an aft CG location.
(b) It decreases with a forward CG, lower altitude, increased mass.
(c) It increases with an increased load factor, in icing conditions and with increased flap
angle.
(d) It increases in a turn and may increase in turbulence.
Q8.9 All other factors remaining constant, the stalling speed increases when:
(a) spoilers are retracted
(b) pulling out of a dive
(c) the mass decreases
(d) altitude is increased
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182 STALLING

Q8.10 The percentage increase of the stalling speed for a level 45◦ banked turn is:
(a) 31%
(b) 41%
(c) 52%
(d) 19%
Q8.11 The angle of attack at which an aeroplane stalls may be increased by the use of:
(a) flaps
(b) spoilers
(c) speed brakes
(d) slats
Q8.12 Which of the following statements regarding the spin is correct?
(a) in a spin the airspeed continually increases
(b) all aeroplanes are designed so that they can never spin
(c) during spin recovery the ailerons should be in the neutral position
(d) an aeroplane is most likely to spin when the stall starts at the wing root
Q8.13 Which of the following devices together provide stall warning?
(a) Stick shaker and angle of attack indicator
(b) Angle of attack indicator and airspeed indicator
(c) Angle of attack sensor and stallstrip
(d) Stick shaker and angle of attack sensor
Q8.14 The IAS of the stall will change in accordance with the following factors. It will:
(a) increase during a turn, increase with increased mass and increase with a forward CG
(b) decrease with a forward CG, decrease with higher altitude and decrease with a forward-
mounted engine
(c) increase with an increased load factor, increase with ice accretion and increase with an aft
CG
(d) increase with an increased load factor, increase with a greater flap angle and decrease during
a turn
Q8.15 The effect on the stall that the downwash from a swept wing contacting a horizontal tail has is
that it causes:
(a) a nose-up tendency and/or lack of elevator response
(b) nose-down tendency
(c) increased sensitivity of elevator inputs
(d) a tendency to accelerate after the stall
Q8.16 On entering a stall the CP of a straight-winged aeroplane will (i) . . . . . . . . and of a swept-wing
aeroplane will (ii) . . . . . . . . . . .
(a) (i) move aft; (ii) not move
(b) (i) move aft; (ii) move forward
(c) (i) move aft; (ii) move aft
(d) (i) not move; (ii) move forward
Q8.17 The boundary layer of a wing is caused by:
(a) a layer of highly viscous air on the wing surfaces
(b) the normal shockwave at transonic speeds
(c) a turbulent stream pattern around the wing
(d) negative pressure above the upper surface
Q8.18 The vane of a stall-warning system with a flapper switch is activated by the movement of the:
(a) point of lowest pressure
(b) stagnation point
(c) centre of pressure
(d) centre of gravity
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SELF-ASSESSMENT EXERCISE 8 183

Q8.19 The percentage lift increase in a 45◦ banked turn compared with straight and level flight is:
(a) 41%
(b) 19%
(c) 31%
(d) 52%
Q8.20 At high altitudes, the stalling speed (IAS):
(a) increases
(b) decreases
(c) remains constant
(d) decreases up to the tropopause and then increases
Q8.21 An aeroplane in straight and level flight has a stalling speed of 100 kt. If the load factor in a turn
is 2 then the stalling speed is:
(a) 70 kt
(b) 200 kt
(c) 141 kt
(d) 282 kt
Q8.22 The pitch-up effect of an aeroplane with swept wings in a stall is due to:
(a) aft movement of the CG
(b) forward movement of the CG
(c) the wing root stalling first
(d) the wing tip stalling first
Q8.23 The function of the stick pusher is:
(a) beyond a predetermined angle of attack to activate and push the stick forward
(b) to activate and push the stick forward before the stick shaker
(c) to vibrate the controls
(d) to pull the stick, to avoid a high-speed stall
Q8.24 During an erect spin recovery:
(a) the control column is moved to the most aft position
(b) the ailerons are held in the neutral position
(c) the control column is moved sideways in the opposite direction to the bank
(d) the control column is moved sideways in the same direction as the bank
Q8.25 The normal stall recovery procedure for a light single-engined aeroplane is:
(a) idle thrust and stick roll neutral and no other corrections
(b) idle thrust and stick roll neutral waiting for the natural nose-down tendency
(c) full thrust and stick roll-neutral nose-down, correcting for angle of bank with rudder
(d) full thrust and stick-roll neutral nose-down, correcting for angle of bank with stick
Q8.26 The type of stall that has the largest associated angle of attack is:
(a) accelerated
(b) low speed
(c) deep
(d) shock
Q8.27 At low speed, the pitch-up phenomenon experience by swept-wing aeroplanes:
(a) is caused by a boundary-layer fence on the wings
(b) is caused by a wing tip stall
(c) never occurs, because swept wings prevent pitch-up
(d) is caused by the extension of trailing edge lift augmentation devices
Q8.28 Vortex generators on the upper surface of a wing will:
(a) increase the magnitude of the shockwave
(b) decrease the intensity of the shockwave induced air separation
(c) increase the critical Mach number
(d) decrease the spanwise flow at high Mach numbers
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184 STALLING

Q8.29 If the stalling speed in straight and level flight is 100 kt the Vs in a 45◦ banked turn
will be:
(a) 119 kt
(b) 100 kt
(c) 80 kt
(d) 140 kt
Q8.30 The cause of swept-wing aeroplanes pitching up at the stall is:
(a) the rearward movement of the CP
(b) separated airflow at the wing root
(c) negative camber at the wing root
(d) spanwise flow
Q8.31 The effect on the stalling speed of a constant IAS climb as the altitude increases is that it:
(a) is initially constant and then increases at high altitude due to compressibility
(b) is initially constant and decreases at high altitude due to compressibility
(c) remains constant throughout the climb
(d) increases throughout the climb
Q8.32 At which of the following speeds should the stick shaker operate?
(a) 1.15 Vs
(b) 1.2 Vs
(c) 1.5 Vs
(d) 1.05 Vs
Q8.33 In a 15◦ banked turn the stalling speed is 60 kt. For the same aeroplane the stalling speed in a
60◦ banked turn is:
(a) 60 kt
(b) 83 kt
(c) 70 kt
(d) 85 kt
Q8.34 In straight and level flight an aeroplane has a Cl of 0.40. A 1◦ increase/decrease of angle of
attack increases/decreases the Cl by 0.15. A gust of wind causes the angle of attack to decrease
by 2◦ . What is the change to the load factor caused by this event?
(a) +1.65
(b) +0.65
(c) −0.75
(d) −0.35
Q8.35 In straight and level flight an aeroplane has a Cl of 0.40. A 1◦ increase/decrease of angle of
attack increases/decreases the Cl by 0.15. A gust of wind causes the angle of attack to decrease
by 2◦ . What is the revised load factor caused by this event?
(a) 1.65
(b) 0.25
(c) −0.35
(d) 0.65
Q8.36 In straight and level flight an aeroplane has a Cl of 0.40. A 1◦ increase/decrease of angle of
attack increases/decreases the Cl by 0.15. A gust of wind causes the angle of attack to increase
by 2◦ . What is the revised load factor caused by this event?
(a) 1.75
(b) 0.7
(c) 1.4
(d) 1.0
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SELF-ASSESSMENT EXERCISE 8 185

Q8.37 An aeroplane mass 250 000 N stalls at 140 kt. The stalling speed at a mass of 350 000 N is:
(a) 172 kt
(b) 108 kt
(c) 88 kt
(d) 166 kt
Q8.38 If the stalling speed of an aeroplane in straight and level flight is 120 kt. The stalling speed in a
1.5g turn will be:
(a) 81 kt
(b) 147 kt
(c) 100 kt
(d) 150 kt
Q8.39 The stalling speed in a turn is proportional to:
(a) Lift
(b) Mass
√
(c) Load Factor
(d) TAS2
Q8.40 The percentage increase to the straight and level stalling speed in a 55◦ banked turn is:
(a) 32%
(b) 10%
(c) 41%
(d) 45%
Q8.41 The percentage increase to the straight and level load factor in a 55◦ banked turn is:
(a) 45%
(b) 74%
(c) 19%
(d) 10%
Q8.42 The V speed that indicates the straight and level stalling speed in the landing configuration is:
(a) Vs1g
(b) Vs1
(c) Vs0
(d) Vsl
Q8.43 Which of the following design features makes an aeroplane more likely to superstall?
(a) Swept forward wing
(b) Swept-back wing
(c) Engines mounted below the wing
(d) Swept-back wing and a ‘T’ tail
Q8.44 When an aerofoil stalls the lift (i) . . . . . . . . and the drag (ii). . . . . . . . . . .
(a) (i) decreases; (ii) decreases
(b) (i) remains constant; (ii) decreases
(c) (i) decreases; (ii) remains constant
(d) (i) decreases; (ii) increases
Q8.45 The effect that tropical rain has on the drag is (i) . . . . . . . . and on the stalling speed is
(ii) . . . . . . . . . . . . .
(a) (i) increase; (ii) decrease
(b) (i) decrease; (ii) decrease
(c) (i) increase; (ii) increase
(d) (i) decrease; (ii) increase
Q8.46 The forward movement of the CP on a swept-wing aeroplane is caused by:
(a) boundary-layer fences and spanwise flow
(b) tip stalling of the wing
(c) flow separation at the wing root due to spanwise flow
(d) a change in the angle of incidence of the wing
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186 STALLING

Q8.47 The recovery procedure from a stall in a light single-engined aeroplane is:
(a) maximum power; stick forward roll neutral; correct for bank with rudder
(b) maximum power; stick neutral and forward, correct for bank with stick
(c) idle power; stick neutral; wait for normal nose-down tendency
(d) idle power; stick-roll neutral and forward
Q8.48 When entering a stall the CP of a straight wing aeroplane will (i) . . . . . . . . . . . and for a highly
swept wing will (ii) . . . . . . . . . . . . . .
(a) (i) move aft; (ii) move aft
(b) (i) move aft; (ii) not move
(c) (i) move aft; (ii) move forward
(d) (i) not move; (ii) move aft
Q8.49 When an aeroplane wing stalls:
(a) A swept wing will stall from the wing root and the CP will move aft.
(b) A swept wing will stall from the tip and the CP will move forward.
(c) A straight wing will stall from the wing tip and the CP will move aft.
(d) A straight wing will stall from the wing root and the CP will move forward.
Q8.50 If the critical angle of attack is exceeded then lift will (i) . . . . . . . . . and drag will (ii) . . . . . . . . .
(a) (i) decrease; (ii) decrease
(b) (i) increase; (ii) increase
(c) (i) decrease; (ii) remain constant
(d) (i) decrease; (ii) increase
Q8.51 Where does flow separation commence at high angles of attack?
(a) upper surface towards the trailing edge
(b) upper surface towards the leading edge
(c) lower surface towards the trailing edge
(d) lower surface towards the leading edge
Q8.52 The stall behaviour of a swept-wing aeroplane as a result of the turbulent downwash contacting
the horizontal tail is:
(a) nose-down
(b) nose-up
(c) tendency to accelerate after the stall
(d) nose-up and/or elevator ineffectiveness
Q8.53 Stalling speed increases when:
(a) recovering from a steep dive
(b) the mass decreases
(c) the flaps are deployed
(d) there are minor height changes in the lower atmosphere
Q8.54 The combination of characteristics most likely to make an aeroplane more susceptible to a deep
stall are:
(a) swept wing and wing-mounted engines
(b) swept wing and ‘T’ tailplane
(c) straight wing and wing-mounted engines
(d) straight wing and ‘T’ tailplane
Q8.55 The IAS of a stall:
(a) increases with increased altitude; increased flaps; slats
(b) increases with altitude; forward CG and icing
(c) aft CG and increasing altitude
(d) altitude does not affect the stall speed IAS
Q8.56 An aeroplane at low subsonic speed will never stall if the:
(a) CAS is kept above the power-on stalling speed
(b) IAS is kept above the power-on stalling speed
(c) critical angle of attack is not exceeded
(d) pitch angle is negative
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SELF-ASSESSMENT EXERCISE 8 187

Q8.57 The angle of attack at the stall:

(a) increases with a forward CG
(b) increases with an aft CG
(c) decreases with a decrease of mass
(d) is not affected by mass changes
Q8.58 The stall-warning device is activated by movement of:
(a) CG
(b) CP
(c) stagnation point
(d) AC
Q8.59 Which of the following increases the stalling angle?
(a) flaps
(b) slats
(c) spoilers
(d) ailerons
Q8.60 The stalling speed increases when:
(a) mass decreases
(b) spoilers are retracted
(c) altitude is decreased
(d) pulling out of a dive
Q8.61 Vortex generators are fitted to:
(a) de-energise the boundary layer
(b) prevent tip stalling
(c) prevent spanwise airflow
(d) reduce the severity of the shock-induced airflow separation
Q8.62 The method by which vortex generators achieve their purpose is that they:
(a) transfer energy from the free airstream to the boundary layer
(b) decrease the kinetic energy to delay the separation
(c) diminish the adverse pressure gradient
(d) redirect the spanwise flow
Q8.63 The stalling speed in a 60◦ banked turn increases by a factor of:
(a) 1.30
(b) 2.00
(c) 1.41
(d) 1.07
Q8.64 The stalling speed in a 60◦ banked turn at a constant altitude will be . . . . . . . . . . times greater
than the level flight stalling speed.
(a) 1.60
(b) 1.19
(c) 1.41
(d) 2.00
Q8.65 At high altitude an aeroplane encounters severe turbulence but no high-speed buffet. In these
conditions if the aeroplane decelerates the type of stall most likely to be experienced first is:
(a) low-speed
(b) accelerated
(c) deep
(d) shock
Q8.66 Vortex generators:
(a) transfer the energy from the free airflow to the boundary layer
(b) change the turbulent boundary layer into a laminar boundary layer
(c) reduce the spanwise flow of a swept wing
(d) take kinetic energy out of the boundary layer to reduce the separation
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188 STALLING

Q8.67 Vortex generators on the upper surface of the wing will:

(a) decrease the stalling speed by increasing the tangential velocity of the swept wing
(b) increase the effectiveness of the spoiler due to the increase of parasite drag
(c) decrease the shock-wave-induced separation
(d) decrease the interference drag of the trailing-edge flaps
Q8.68 Vortex generators:
(a) induce laminar flow by using the free-stream flow
(b) prevent spanwise flow
(c) increase the energy of the turbulent boundary layer by using the free-stream flow
(d) induce boundary-layer separation using the energy of the laminar flow
Q8.69 An aeroplane at take-off has a mass of 10 000 kg and a basic stalling speed of 150 kt. On approach
to land the aeroplane has a mass of 7500 kg, 30◦ angle of bank and land flap selected that doubles
the value of Clmax. The stalling speed in this configuration is:
(a) 112 kt
(b) 99 kt
(c) 130 kt
(d) 158 kt
Q8.70 In steady horizontal flight the Cl of an aeroplane is 0.35. A one-degree increase in the AoA
increases the Cl by 0.079. A vertical gust of air instantly changes the AoA by three degrees. The
increase of the load factor is:
(a) 1.9
(b) 1.68
(c) 0.9
(d) 0.68
Q8.71 The cause of swept-wing aeroplanes having a tendency to pitch nose-up is:
(a) using devices that augment lift
(b) wing-tip stalling
(c) wing fences
(d) vortex generators
Q8.72 The reason that swept-wing aeroplanes are more likely to deep stall is:
(a) the CP moves aft
(b) the CP moves forward
(c) the wing root stalls first
(d) The upper surface spanwise flow is from tip to root