INDIGO AERODYNAMIC 5259-5689 - Dgca question bank for pilots

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#1. A laminar boundary layer is a layer, in which:

the velocity is constant

the vortices are weak

no velocity components exist, normal to the surface

the temperature varies constantly.

layer which is close to the surface

#2. Compared with level flight prior to the stall, the lift (1) and drag (2) in the stall change as follows :

(1) decreases (2) decreases.

(1) increases (2) increases

(1) increases (2) decreases.

(1) decreases (2) increases.

#3. Entering the stall the centre of pressure of a straight (1) wing and of a strongly swept back wing (2) will:

(1) move aft, (2) not move.

(1) move aft, (2) move forward.

(1) not move (2) move forward

(1) move aft, (2) move aft.

#4. Which of the following statements about the stall of a straight wing aeroplane is correct?

Buffeting is the result of flow separation on the tail plane

The horizontal tail will stall at a higher speed than the wing

The nose down effect is the result of increasing downwash, due to flow separation

Just before the stall the aeroplane will be have a nose-down tendency

#5. Which statement is correct about the laminar and turbulent boundary layer :

friction drag will be equal in both types of layers

friction drag is lower in the laminar layer

friction drag is lower in the turbulent layer

separation point will occur earlier in the turbulent layer

#6. After the transition point between the laminar and turbulent boundary layer

the mean speed and friction drag increases

the boundary layer gets thinner and the speed increases

the boundary layer gets thicker and the speed decreases

the mean speed increases and the friction drag decreases

#7. Which kind of boundary layer has the strongest change in velocity close to the surface?

Laminar boundary layer

No difference

Turbulent boundary layer

Transition boundary layer

#8. The stall speed in a 60° banked turn increases by the following factor:

1.41

1.07

2.00

1.30

#9. In a turn, the load factor n and the stalling speed VS will be:

n greater than 1, VS lower than in straight and level flight.

n smaller than 1, VS lower than in straight and level flight

n greater than 1, VS higher than in straight and level flight

n smaller than 1, VS higher than in straight and level flight.

#10. A jet aeroplane cruises buffet free at high constant altitude in significant turbulence. Which type of stall can occur if this aeroplane decelerates?

Low speed stall.

Shock stall.

Deep stall

Accelerated stall.

#11. Which of the following situations leads to a decreasing stall speed (IAS)?

increasing air density

decreasing weight

increasing load factor

increasing altitude

#12. Two identical aeroplanes A and B are flying horizontal steady turns. Further data are:A:W= 1500 kgBank= 20°TAS= 130 ktB:W= 1500 kgBank= 20°TAS= 200 ktWhich of the following statements is correct?

The load factor A is larger than the load factor B.

The rate of turn A is larger than the rate of turn B.

The turn radius A is larger than the turn radius B.

The lift coefficient A is smaller than the lift coefficient B.

#13. Increase of wing loading will:

increase CLmax

decrease take off speeds.

increase the stall speeds

decrease the minimum gliding angle.

#14. The stall speed :

increases with the length of the wingspan

decreases with an increased weight

does not depend on weight

increases with an increased weight

#15. When a pilot makes a turn in horizontal flight, the stall speed :

increases with the square root of load factor

increases with the load factor squared

increases with flap extension

decreases with increasing bank angle

#16. An aeroplane has a stall speed of 78 KCAS at its gross weight of 6850 Ibs. What is the stall speed when the weight is 5000 Ibs ?

91 KCAS

57 KCAS

78 KCAS

67 KCAS

#17. An aeroplane has a stall speed of 100 kt at a load factor n=1. In a turn with a load factor of n=2, the stall speed is:

70 kt

282 kt

141 kt

200 kt

#18. The following factors increase stall speed :

an increase in load factor, a forward c.g. shift, decrease in thrust.

a higher weight, selecting a higher flap setting, a forward c .g. shift.

a lower weight, decreasing bank angle, a smaller flapsetting

increasing bank angle, increasing thrust, slat extension.

#19. The wing of an aeroplane will never stall at low subsonic speeds as long as….

there is a nose-down attitude

the CAS exceeds the power-on stall speed

the IAS exceeds the power-on stall speed

the angle of attack is smaller than the value at which the stall occurs.

#20. The stall speed increases, when: (all other factors of importance being constant)

minor altitude changes occur e.g. 0-10.000 ft.

spoilers are selected from OUT to IN.

pulling up from a dive

weight decreases

#21. By what approximate percentage will the stall speed increase in a horizontal coordinated turn with a bank angle of 45° ?

19%

52%

31%

41%

#22. An aeroplane has a stalling speed of 100 kt in a steady level flight. When the aeroplane is flying a level turn with a load factor of 1.5, the stalling speed is:

141 kt

150 kt.

82 kt.

122 kt.

#23. The stalling speed in IAS will change according to the following factors:

May increase when the c.g. moves forward, with higher altitude and due to the slip stream from a propellor on an engine located forward of the wing

May increase with altitude, especially high altitude, will increase during icing conditions and will increase when the c.g. moves forward

Will increase with increased load factor, more flaps and increased bank angle in a turn

Will increase in a turn, higher temperature and will increase when the c.g. moves aft

#24. The stalling speed in IAS will change according to the following factors:

Increase during turn, increased mass and forward c.g. location

Decrease in a forward c.g. location, higher altitude and due to the slip stream from a propeller on an engine located forward of the wing

Increase with increased load factor, icing conditions and an aft c.g. location

Increase with increased load factor, more flaps but will not increase due to the bank angle in a turn

#25. The stalling speed in IAS will change according to the following factors:

Will increase during turn, increased mass and an aft c.g. location

May increase during turbulence and will always increase when banking in a turn

Will increase with increased load factor, icing conditions and more flaps

Will decrease with a forward c.g. location, lower altitude and due to the slip stream from a propeller on an engine located forward of the wing

#26. A boundary layer fence on a swept wing will:

improve the lift coefficient of the trailing edge flap

increase the critical Mach Number

improve the low speed characteristics

improve the high speed characteristics

#27. Which of the following are used as stall warning devices?

Stick shaker and stallstrip

Angle of attack sensor and stallstrip

Stick shaker and angle of attack indicator

Angle of attack indicator and speed indicator

#28. The vane of a stall warning system with a flapper switch is activated by the change of the:

point of lowest pressure.

stagnation point

centre of pressure.

centre of gravity

#29. The normal stall recovery procedure for a light single engined aeroplane is:

full power and stick roll-neutral nose-down, correction for angle of bank with stick.

idle power and stick neutral, waiting for the natural nose-down tendency.

full power and stick roll-neutral nose-down, correcting for angle of bank with rudder.

idle power and stick roll-neutral nose-down and no other corrections

#30. Compared with stalling airspeed (VS) in a given configuration, the airspeed at which stick shaker will be triggered is:

1.12 VS

1.30 VS.

1.20 VS.

greater than VS

#31. The sensor of a stall warning system can be activated by a change in the location of the

centre of lift.

stagnation point

transition region

centre of gravity

#32. On a swept wing aeroplane at low airspeed, the “”pitch up”” phenomenon:

is caused by boundary layer fences mounted on the wings

is caused by wingtip stall.

is caused by extension of trailing edge lift augmentation devices

never occurs, since a swept wing is a ""remedy"" to pitch up

#33. Low speed pitch up is caused by the:

spanwise flow on a swept forward wing

Mach trim system

wing tip vortex

spanwise flow on a swept back wing.

#34. The most important problem of ice accretion on an aeroplane during flight is:

blocking of control surfaces.

reduction in CLmax

increase in drag

increase in weight.

#35. The effects of very heavy rain (tropical rain) on the aerodynamic characteristics of an aeroplane are:

increase of CLmax and decrease of drag

decrease of CLmax and decrease of drag

decrease of CLmax and increase of drag

increase of CLmax and increase of drag

#36. Which of the following statements about stall speed is correct ?

Use of a T-tail will decrease the stall speed

Decreasing the angle of sweep of the wing will decrease the stall speed

Increasing the anhedral of the wing will decrease the stall speed

Increasing the angle of sweep of the wing will decrease the stall speed.

#37. Which of the following statements about the spin is correct?

During spin recovery the ailerons should be kept in the neutral position

In the spin, airspeed continuously increases

An aeroplane is prone to spin when the stall starts at the wing root

Every aeroplane should be designed such that it can never enter a spin

#38. During an erect spin recovery:

the control stick is moved side ways, in the direction of the angle of bank

the control stick is moved side ways, against the angle of bank.

the ailerons are held in the neutral position

the control stick is pulled to the most aft position

#39. Which combination of design features is known to be responsible for deep stall?

Straight wings and aft fuselage mounted engines

Straight wings and a T-tail

Swept back wings and wing mounted engines

Swept back wings and a T-tail

#40. A strongly swept back wing stalls. If the wake of the wing contacts the horizontal tail, the effect on the stall behaviour can be:

nose up tendency and/or lack of elevator response

increase sensitivity of elevator inputs

nose down tendency

tendency to increase speed after initial stall

#41. The function of the stick pusher is:

to vibrate the controls

to activate and push the stick forward at or beyond a certain value of angle of attack.

to activate and push the stick forward prior to stick shaker

to pull the stick, to avoid a high speed stall

#42. Stick pushers must be installed in aeroplanes with dangerous stall characteristics. Dangerous stall characteristics include:

Excessive wing drop and deep stall

pitch down and increase in speed

pitch down and minor wing drop

pitch down and yaw

#43. Which type of stall has the largest associated angle of attack?

Shock stall.

Accelerated stall

Low speed stall.

Deep stall.

#44. Which aeroplane design has the highest probability of a super stall?

A low horizontal tail

Swept wings

A canard wing

A T-tail

#45. The pitch up effect of an aeroplane with swept wing in a stall is due to the

aft movement of the centre of gravity

forward movement of the centre of gravity

wing tip stalling first.

wing root stalling first

#46. One disadvantage of the swept back wing is it’s stalling characteristics. At the stall :

tip stall will occur first, which produces a pitch-up moment.

wing root stall will occur first, which produces a rolling moment

tip stall will occur first, which produces a nose-down moment

leading edge stall will occur first, which produces a nose-down moment

#47. Trailing edge flap extension will:

decrease the critical angle of attack and increase the value of CLmax.

increase the critical angle of attack and increase the value of CLmax.

increase the critical angle of attack and decrease the value of CLmax

decrease the critical angle of attack and decrease the value of CLmax.

#48. Which of the following series of configurations has an increasing critical angle of attack ?

slats only extended, clean wing, flaps only extended

slats only extended, flaps only extended, clean wing

flaps only extended, clean wing, slats only extended

clean wing, flaps only extended, slats only extended

#49. An aeroplane with swept back wings is equipped with slats and/or leading edge (L.E.) flaps. One possible efficient way to arrange the leading edge devices on the wings is:

Wing roots: slatsWing tips: L.E. flaps

Wing roots: L.E. flapsWing tips: slats

Wing roots: slatsWing tips: no devices

Wing roots: L.E. flapsWing tips: no devices

#50. An aeroplane has the following flap settings : 0°, 15°, 30° and 45°. Slats can be selected too. Which of the above selections will produce the greatest negative influence on the CL/CD ratio?

Flaps from 0° to 15°.

Flaps from 15° to 30°.

Flaps from 30° to 45°.

The slats

#51. After take-off the slats (when installed) are always retracted later than the flaps. Why ?

Because SLATS EXTENDED provides a better view from the cockpit than FLAPS EXTENDED

Because SLATS EXTENDED gives a large decrease in stall speed with relatively less drag

Because VMCA with SLATS EXTENDED is more favourable compared to the FLAPS EXTENDED situation

Because FLAPS EXTENDED gives a large decrease in stall speed with relatively less drag.

#52. Which statement is correct?

Spoiler extension decreases the stall speed and the minimum rate of descent, but increases the minimum descent angle

Extension of flaps will increase (CL/CD)max, causing the minimum rate of descent to decrease.

Extension of flaps causes a reduction of the stall speed, the maximum glide distance also reduces

Extension of flaps has no influence on the minimum rate of descent, as only the TAS has to be taken into account

#53. The trailing edge flaps when extended :

significantly lower the drag

significantly increase the angle of attack for maximum lift

worsen the best angle of glide

increase the zero lift angle of attack

#54. When the trailing edge flaps are deflected in level flight, the change in pitch moment will be:

dependent on c.g. location

zero.

nose up

nose down

#55. Extension of FOWLER type trailing edge lift augmentation devices, will produce:

a force which reduces drag.

no pitching moment

a nose-down pitching moment

a nose-up pitching moment

#56. On a wing fitted with a “”fowler”” type trailing edge flap, the “”Full extended”” position will produce:

an unaffected CD, at a given angle of attack

an unaffected wing area and increase in camber

an increase in wing area and camber

an increase in wing area only

#57. When flaps are extended in a straight and level flight at constant IAS, the lift coefficient will eventually :

remain the same

increase.

first increase and then decrease

decrease.

#58. When flaps are deployed at constant angle of attack the lift coefficient will:

increase.

vary as the square of IAS

decrease.

remain the same

#59. What is the most effective flap system?

Split flap.

Single slotted flap

Plain flap

Fowler flap

#60. Deploying a Fowler flap, the flap will:

just turn down

turn down, then move aft.

just move aft

move aft, then turn down

#61. A slotted flap will increase the CLmax by:

increasing the camber of the aerofoil and improving the boundary layer

decreasing the skin friction

increasing only the camber of the aerofoil.

increasing the critical angle of attack

#62. In order to maintain straight and level flight at a constant airspeed, whilst the flaps are being retracted, the angle of attack will:

increase.

increase or decrease depending on type of flap.

remain constant.

decrease.

#63. Flap selection at constant IAS in straight and level flight will increase the :

stall speed

lift and the drag

lift coefficient and the drag

maximum lift coefficient (CLmax) and the drag

#64. During flap down selection in a continuous straight and level flight at constant IAS and weight:

the lift coefficient and the drag coefficient increase.

the centre of pressure moves aft

the total boundary layer becomes laminar

the stall speed increases

#65. A plain flap will increase CLmax by

increasing the camber of the aerofoil

increasing angle of attack

boundary layer control.

centre of lift movement

#66. During the retraction of the flaps at a constant angle of attack the aeroplane starts to (all other factors of importance being constant)

sink suddenly

climb.

bank.

yaw.

#67. During the extension of the flaps at a constant angle of attack the aeroplane starts to (all other factors of importance being constant)

yaw.

bank.

sink suddenly

climb.

#68. Compared with the flap up configuration the maximum angle of attack for the flaps down configuration is

larger.

smaller.

smaller or larger depending on flap deflection.

unchanged.

#69. Deflection of leading edge flaps will:

decrease drag

decrease CLmax

increase critical angle of attack

not affect critical angle of attack

#70. Slat extension will:

increase critical angle of attack.

create gaps between leading edge and engine nacelles.

reduce tip vortices.

decrease the energy in the boundary layer on the upperside of the wing

#71. Which of the following statements about the difference between Krueger flaps and slats is correct?

Deploying a Krueger flap will form a slot, deploying a slat does not.

Deploying a slat will increase critical angle of attack, deploying a Krueger flap does not

Deploying a Krueger flap will increase critical angle of attack, deploying a slat does not.

Deploying a slat will form a slot, deploying a Krueger flap does not.

#72. What is the purpose of an auto-slat system ?

extend automatically when a certain value of angle of atttack is exceeded.

ensures that the slats are always extended when the ground/flight system is in the ""ground"" position.

provide automatically slat IN selection after take-off.

assist the ailerons during rolling.

#73. The function of the slot between an extended slat and the leading edge of the wing is to:

cause a venturi effect which energizes the boundary layer

allow space for vibration of the slat

slow the air flow in the slot so that more pressure is created under the wing

reduce the wing loading

#74. A deployed slat will:

increase the camber of the aerofoil and increase the effective angle of attack, so that CLmax is reached at higher angles of attack.

decrease the boundary layer energy and decrease the suction peak on the slat, so that CLmax is reached at lower angles of attack.

increase the boundary layer energy and increase the suction peak on the fixed part of the wing, so that the stall is postponed to higher angles of attack.

increase the boundary layer energy, move the suction peak from the fixed part of the wing to the slat, so that the stall is postponed to higher angles of attack.

#75. What increases the stalling angle of attack ? Use of :

flaps

slats

fuselage mounted speed-brakes

spoilers

#76. The use of a slot in the leading edge of the wing enables the aeroplane to fly at a slower speed because :

it delays the stall to a higher angle of attack

the laminar part of the boundary layer gets thicker

it changes the camber of the wing

it decelerates the upper surface boundary layer air

#77. A slat will

increase the lift by increasing the wing area and the camber of the aft portion of the wing.

provide a boundary layer suction on the upper side of the wing.

increase the camber of the aerofoil and divert the flow around the sharp leading edge

increase the boundary layer energy and prolongs the stall to a higher angle of attack.

#78. Vortex generators:

transfer energy from the free airflow into the boundary layer.

take kinetic energy out of the boundary layer to reduce separation.

reduce the spanwise flow on swept wing

change the turbulent boundary layer into a laminar boundary layer

#79. Spoiler deflection causes :

decrease in lift and drag

an increase in lift and drag

an increase in lift only

an increase in drag and decrease in lift

#80. Upon extension of a spoiler on a wing:

only CL is decreased (CD remains unaffected).

CD is increased, while CL remains unaffected.

CD is increased and CL is decreased

both CL and CD are increased

#81. When “”spoilers”” are used as speed brakes:

at same angle of attack, CD is increased and CL is decreased.

CLmax of the polar curve is not affected

they do not affect wheel braking action during landing.

at same angle of attack, CL remains unaffected

#82. There are two types of boundary layer: laminar and turbulent. One important advantage the turbulent boundary layer has over the laminar type is that :

energy is less

it has less tendency to separate from the surface

it is thinner

skin friction drag is less

#83. In which phase of the take-off is the aerodynamic effect of ice located on the wing leading edge most critical?

The last part of the rotation

The take-off run.

During climb with all engines operating.

All phases of the take-off are equally critical.

#84. The formula for the Mach Number is:(a= speed of sound)

M= TAS*a

M= TAS / a

M= a / TAS

M= IAS / a

#85. The Mach number:

increases at a given TAS, when the temperature rises.

is the ratio between the TAS of the aeroplane and the local speed of sound

is the ratio between the IAS of the aeroplane and the local speed of sound

is the ratio between the TAS of the aeroplane and the speed of sound at sea level.

#86. Climbing at a constant Mach Number up to FL 350 the TAS will:

decrease.

remain constant

increase.

first increase, then decrease.

#87. The flight Mach number is 0.8 and the TAS is 400 kts. The speed of sound is:

500 kts

320 kts

480 kts

#88. Which statement with respect to the speed of sound is correct ?

Varies with the square root of the absolute temperature.

Is independent of altitude

Doubles if the temperature increases from 9° to 36° Centigrade.

Increases always if the density of the air decreases

#89. If the altitude is increased and the TAS remains constant in the standard troposphere the Mach Number will

not change.

increase or decrease, depends of the type of aeroplane

increase.

decrease.

#90. The speed of sound is affected by the:

pressure of the air

density of the air

humidity of the air.

temperature of the air.

#91. An aeroplane is descending at a constant Mach number from FL 350. What is the effect on true airspeed ?

It decreases as pressure increases

It increases as temperature increases

It remains constant

It decreases as altitude decreases

#92. To be able to predict compressibility effects you have to determine the:

IAS.

TAS.

Mach Number

EAS.

#93. A normal shock wave:

is a discontinuity plane in an airflow, in which the pressure drops suddenly

is a discontinuity plane in an airflow, in which the temperature drops suddenly.

is a discontinuity plane in an airflow, which is always normal to the surface

can occur at different points on the aeroplane in transonic flight.

#94. Which statement is correct about a normal shock wave ?

The airflow changes from supersonic to subsonic

The airflow changes direction

The airflow expands when passing the aerofoil

The airflow changes from subsonic to supersonic

#95. Compared with an oblique shock wave at the same Mach number a normal shock wave has a

higher compression

smaller compression

higher expansion

smaller expansion

#96. Compared with an oblique shock wave at the same Mach number a normal shock wave has a

higher total temperature

lower static temperature

higher loss in total pressure

higher total pressure

#97. The regime of flight from the critical Mach number up to M = 1.3 is called the

supersonic range

transonic range

subsonic range

hypersonic range

#98. Mcrit is the free stream Mach Number at which:

somewhere about the airframe Mach 1 is reached locally

the critical angle of attack is reached

Mach buffet occurs.

shockstall occurs

#99. When the Mach number is slowly increased in straight and level flight the first shockwaves will occur:

somewhere on the fin

somewhere on the hoizontal tail.

at the wing root segment, upperside

on the underside of the wing

#100. The critical Mach Number of an aeroplane is the free stream Mach Number, which produces the first evidence of :

supersonic flow.

shock wave

local sonic flow

buffet.