Exam quiz Principles of Flight (Aeroplane) - SPL - Sailplane Pilot License

Question 1

What types of boundary layers can be found on an aerofoil?

Accepted Answer

Laminar layer at the leading wing areas, turbulent boundary layer at the trailing areas

Answer

Laminar boundary layer along the complete upper surface with non-separated airflow

Answer

Turbulent layer at the leading wing areas, laminar boundary layer at the trailing areas

Answer

Turbulent boundary layer along the complete upper surface with separated airflow

Question 2

Which parts of an aircraft mainly affect the generation of induced drag?

Accepted Answer

The wing tips.

Answer

The front part of the fuselage.

Answer

The outer part of the ailerons.

Answer

The lower part of the gear.

Question 3

Which design feature can compensate for adverse yaw?

Accepted Answer

Differential aileron defletion

Answer

Which design feature can compensate for adverse yaw?

Answer

Full deflection of the aileron

Answer

Wing dihedral

Question 4

What pressure pattern can be observed at a lift-generating wing profile at positive angle of attack?

Accepted Answer

Low pressure is created above, higher pressure below the profile

Answer

Pressure above remains unchanged, higher pressure is created below the profile

Answer

High pressure is created above, lower pressure below the profile

Answer

Pressure below remains unchanged, lower pressure is created above the profile

Question 5

What is the function of the horizontal tail (among other things)?

Accepted Answer

To stabilise the aeroplane around the lateral axis

Answer

To stabilise the aeroplane around the longitudinal axis

Answer

To initiate a curve around the vertical axis

Answer

To stabilise the aeroplane around the vertical axis

Question 6

Through which factor listed below does the load factor increase during cruise flight?

Accepted Answer

An upward gust

Answer

Lower air density

Answer

A forward centre of gravity

Answer

Higher aeroplane weight

Question 7

What engine design at a Touring Motor Glider (TMG) results in least drag?

Accepted Answer

Engine and propeller mounted stowable on the fuselage

Answer

Engine and propeller mounted fix on the fuselage

Answer

Engine and propeller mounted fix at the aircraft's nose

Answer

Engine and propeller mounted fix at the horizontal stabilizer

Question 8

The laminar boundary layer on the aerofoil is located between...

Accepted Answer

The stagnation point and the transition point.

Answer

The stagnation point and the center of pressure.

Answer

The transition point and the separation point.

Answer

The transition point and the center of pressure.

Question 9

Which of the listed wing shapes has the lowest induced drag?

Accepted Answer

Elliptical shape

Answer

Rectangular shape

Answer

Trapezoidal shape

Answer

Double trapezoidal shape

Question 10

In a co-ordinated turn, how is the relation between the load factor (n) and the stall speed (Vs)?

Accepted Answer

N is greater than 1, Vs is greater than in straight and level flight.

Answer

N is smaller than 1, Vs is greater than in straight and level flight.

Answer

N is greater than 1, Vs is smaller than in straight and level flight.

Answer

N is smaller than 1, Vs is smaller than in straight and level flight.

Question 11

Which point on the aerofoil is represented by number 1? See figure (PFA-009) Siehe Anlage 2

Accepted Answer

Stagnation point

Answer

Center of pressure

Answer

Transition point

Question 12

Bernoulli's equation for frictionless, incompressible gases states that...

Accepted Answer

Total pressure = dynamic pressure + static pressure.

Answer

Total pressure = dynamic pressure - static pressure.

Answer

Static pressure = total pressure + dynamic pressure

Answer

Dynamic pressure = total pressure + static pressure.

Question 13

The angle (alpha) shown in the figure is referred to as... See figure (PFA-003) DoF: direction of airflow Siehe Anlage 3

Accepted Answer

Angle of attack.

Answer

Lift angle.

Answer

Angle of incidence.

Answer

Angle of inclination

Question 14

Where is interference drag generated?

Accepted Answer

At the wing root

Answer

At the ailerons

Answer

At the the gear

Answer

Near the wing tips

Question 15

Flying with speeds higher than the never-exceed-speed (vNE) may result in...

Accepted Answer

Flutter and mechanically damaging the wings.

Answer

Reduced drag with increased control forces.

Answer

An increased lift-to-drag ratio and a better glide angle.

Answer

Too high total pressure resulting in an unusable airspeed indicator.

Question 16

The ratio of span and mean chord length is referred to as...

Accepted Answer

Aspect ratio.

Answer

Trapezium shape.

Answer

Tapering.

Answer

Wing sweep.

Question 17

Which constructive feature is shown in the figure? See figure (PFA-006) L: Lift Siehe Anlage 4

Accepted Answer

Lateral stability by wing dihedral

Answer

Differential aileron deflection

Answer

Directional stability by lift generation

Answer

Longitudinal stability by wing dihedral

Question 18

What effect is referred to as "adverse yaw"?

Accepted Answer

Aileron operation results in a yaw to the opposite side due to more drag at the down-deflected aileron

Answer

Aileron operation results in a yaw to the desired side due to less drag at the down-deflected aileron

Answer

Rudder operation results in a rolling moment to the opposite side due to more lift generated by the faster moving wing.

Answer

Aileron operation results in a yaw to the opposite side due to more drag at the up-deflected aileron

Question 19

The angle of attack is the angle between...

Accepted Answer

The chord line and the oncoming airflow.

Answer

The chord line and the longitudinal axis of an aeroplane.

Answer

The wing and the fuselage of an aeroplane

Answer

The undisturbed airflow and the longitudinal axis of an aeroplane.

Question 20

Which statement about lift and angle of attack is correct?

Accepted Answer

Increasing the angle of attack too far may result in a loss of lift and an airflow separation

Answer

Increasing the angle of attack results in less lift being generated by the aerofoil

Answer

Decreasing the angle of attack results in more drag being generated by the aerofoil

Answer

Too large angles of attack can lead to an exponential increase in lift

Question 21

Point number 1 in the figure indicates which flight state? See figure (PFA-008) Siehe Anlage 5

Accepted Answer

Inverted flight

Answer

Slow flight

Answer

Stall

Answer

Best gliding angle

Question 22

In case of a stall it is important to...

Accepted Answer

Decrease the angle of attack and increase the speed.

Answer

Increase the angle of attack and increase the speed.

Answer

Increase the angle of attack and reduce the speed.

Answer

Increase the bank angle and reduce the speed.

Question 23

Which of the following options is likely to produce large induced drag?

Accepted Answer

Small aspect ratio

Answer

Large aspect ratio

Answer

Low lift coefficients

Answer

Tapered wings

Question 24

The glide ratio of a sailplane can be improved by which measures?

Accepted Answer

Cleaning, correct speed, retractable gear, taped gaps between wing and fuselage

Answer

Higher airplane mass, thin airfoil, taped gaps between wing and fuselage

Answer

Lower airplane mass, correct speed, retractable gear

Answer

Forward C.G. position, correct speed, taped gaps between wing and fuselage

Question 25

Number 3 in the drawing corresponds to the... See figure (PFA-010) Siehe Anlage 1

Accepted Answer

Camber line.

Answer

Thickness.

Answer

Chord.

Answer

Chord line.

Question 26

What structural item provides lateral stability to an airplane?

Accepted Answer

Wing dihedral

Answer

Vertical tail

Answer

Differential aileron deflection

Answer

Elevator

Question 27

Rotation around the vertical axis is called...

Accepted Answer

Yawing.

Answer

Slipping.

Answer

Pitching.

Answer

Rolling.

Question 28

The critical angle of attack...

Accepted Answer

Is not changed by different aircraft weights.

Answer

Increases with a front centre of gravity

Answer

Is changed by different aircraft weights.

Answer

Decreases with a rear centre of gravity.

Question 29

During a stall, the lift...

Accepted Answer

Decreases and drag increases.

Answer

Increases and drag increases.

Answer

Decreases and drag decreases

Answer

Increases and drag decreases.

Question 30

Pressure compensation on an wing occurs at the...

Accepted Answer

Wing tips.

Answer

Leading edge.

Answer

Trailing edge.

Answer

Wing roots

Question 31

Which statement regarding a spin is correct?

Accepted Answer

During recovery the ailerons should be kept neutral

Answer

During the spin the speed constantly increases

Answer

During recovery the ailerons should be crossed

Answer

Only very old aeroplanes have a risk of spinning

Question 32

The trim tab at the elevator is defelected upwards. In which position is the corresponding indicator?

Accepted Answer

Nose-down position

Answer

Neutral position

Answer

Nose-up position

Answer

Laterally trimmed

Question 33

How does a laminar boundary layer differ from a turbulent boundary layer?

Accepted Answer

The turbulent boundary layer can follow the airfoil camber at higher angles of attack

Answer

The laminar boundary layer is thinner and provides more skin-friction drag

Answer

The laminar boundary layer produces lift, the turbulent boundary layer produces drag

Answer

The turbulent boundary layer is thicker and provides less skin-friction drag

Question 34

Considering longitudinal stability, which C.G. position is most dangerous with a normal gliding plane?

Accepted Answer

Position beyond the rear C.G. limit

Answer

Position beyond the front C.G. limit

Answer

Position too far aside permissable C.G. limits.

Answer

Position far back within permissable C.G. limits

Question 35

The pressure compensation between wind upper and lower surface results in ...

Accepted Answer

Induced drag by wing tip vortices

Answer

Laminar airflow by wing tip vortices.

Answer

Profile drag by wing tip vortices.

Answer

Lift by wing tip vortices.

Question 36

At stationary glide and the same mass, what is the difference when using a thick airfoild instead of a thinner airfoil?

Accepted Answer

More drag, same lift

Answer

Less drag, less lift

Answer

More drag, less lift

Answer

Less drag, same lift

Question 37

How do induced drag and parasite drag change with increasing airspeed during a horizontal and stable cruise flight?

Accepted Answer

Induced drag decreases and parasite drag increases

Answer

Parasite drag decreases and induced drag increases

Answer

Parasite drag decreases and induced drag decreases

Answer

Induced drag increases and parasite drag increases

Question 38

Which point on the aerofoil is represented by number 4? See figure (PFA-009) Siehe Anlage 2

Accepted Answer

Separation point

Answer

Transition point

Answer

Stagnation point

Answer

Center of pressure

Question 39

Deflecting the rudder to the left causes...

Accepted Answer

Yawing of the aircraft to the left.

Answer

Pitching of the aircraft to the left

Answer

Pitching of the aircraft to the right.

Answer

Yawing of the aircraft to the right.

Question 40

Rotation around the lateral axis is called...

Accepted Answer

Pitching.

Answer

Yawing.

Answer

Rolling.

Answer

Stalling.

Question 41

What is shown by a profile polar?

Accepted Answer

Ratio of cA and cD at different angles of attack

Answer

Ratio between minimum rate of descent and best glide

Answer

Ratio between total lift and drag depending on angle of attack

Answer

Lift coefficient cA at different angles of attack

Question 42

The elevator moves an aeroplane around the...

Accepted Answer

Lateral axis.

Answer

Vertical axis.

Answer

Longitudinal axis.

Answer

Elevator axis.

Question 43

What structural item provides directional stability to an airplane?

Accepted Answer

Large vertical tail

Answer

Differential aileron deflection

Answer

Wing dihedral

Answer

Large elevator

Question 44

A sailplane is operated with additional water ballast. How do best gliding angle and speed of best glide change, when compared to flying without water ballast?

Accepted Answer

Best gliding angle remains unchanged, best glide speed increases.

Answer

Best gliding angle descreases, best glide speed decreases.

Answer

Best gliding angle remains increases, best glide speed increases.

Answer

Best gliding angle remains unchanged, best glide speed decreases.

Question 45

Which statement about the airflow around an aerofoil is correct if the angle of attack decreases?

Accepted Answer

The center of pressure moves aft

Answer

The center of pressure moves forward

Answer

The stagnation point moves down

Answer

The stagnation point remains constant

Question 46

During approch to the next updraft, the vertical speed indicator reads 3 m/s descent. Within the updraft you expect a mean rate of climb of 2 m/s. According McCready, how should you adjust the speed during approach of the updraft?

Accepted Answer

The McCready ring should be set to 2 m/s, the recommended speed can be read at the McCready scale next to the current rate of descent (3 m/s).

Answer

The McCready ring should be set to 2 m/s, the recommended speed can be read at the McCready scale next to the sum of current rate of descent at expected rate of climb (5 m/s).

Answer

The McCready ring should be set to 3 m/s, the recommended speed can be read at the McCready scale next to the expected rate of climb (2 m/s).

Answer

Outside of thermal cells, the McCready ring should be set to 0 m/s, the recommended speed can be read at the McCready scale next to the current rate of descent (3 m/s).

Question 47

The drag coefficient...

Accepted Answer

Cannot be lower than a non-negative, minimal value.

Answer

Is proportional to the lift coefficient

Answer

Increases with increasing airspeed.

Answer

May range from zero to an infinite positive value

Question 48

The critical angle of attack...

Accepted Answer

Is independent of the weight.

Answer

Decreases with forward center of gravity position.

Answer

Changes with increasing weight.

Answer

Increases with backward center of gravity position.

Question 49

Which statement about induced drag during the horizontal cruise flight is correct?

Accepted Answer

Induced drag decreases with increasing airspeed

Answer

Induced drag has a minimum at a certain speed and increases at higher as well as lower speeds

Answer

Induced drag has a maximum at a certain speed and decreases at higher as well as lower speeds

Answer

Induced drag increases with increasing airspeed

Question 50

What is the result of extending flaps with increasing aerofoil camber?

Accepted Answer

Minimum speed decreases

Answer

Maximum permissable speed increases

Answer

Minimum speed increases

Answer

C.G. position moves forward

Question 51

What is the advantage of differential aileron movement?

Accepted Answer

The drag of the downwards deflected aileron is lowered and the adverse yaw is smaller

Answer

The total lift remains constant during aileron deflection

Answer

The ratio of the drag coefficient to lift coefficient is increased

Answer

The adverse yaw is higher

Question 52

How is the balance of forces affected during a turn?

Accepted Answer

Lift force must be increased to compensate for the sum of centrifugal and gravitational force

Answer

A lower lift force compensates for a lower net force as compared to level flight

Answer

The horizontal component of the lift force during a turn is the centrifugal force

Answer

The net force results from superposition of gravity and centripetal forces

Question 53

In straight and level flight with constant performance of the engine, the angle of attack at the wing is...

Accepted Answer

Smaller than in a climb.

Answer

Smaller than in a descent.

Answer

Greater than in a climb.

Answer

Greater than at take-off.

Question 54

What has to be considered with regard to the center of gravity position?

Accepted Answer

Only correct loading can assure a correct and safe center of gravity position.

Answer

By moving the elevator trim tab, the center of gravity can be shifted into a correct position.

Answer

The center of gravity's position can only be determined during flight.

Answer

By moving the aileron trim tab, the center of gravity can be shifted into a correct position.

Question 55

Number 2 in the drawing corresponds to the... See figure (PFA-010) Siehe Anlage 1

Accepted Answer

Chord line.

Answer

Profile thickness.

Answer

Angle of attack.

Question 56

In order to improve the stall characteristics of an aircraft, the wing is twisted outwards (the angle of incidence varies spanwise). This is known as...

Accepted Answer

Geometric washout.

Answer

Arrow shape.

Answer

V-form

Answer

Aerodynamic washout.

Question 57

Rudder deflections result in a turn of the aeroplane around the...

Accepted Answer

Vertical axis.

Answer

Rudder axis.

Answer

Lateral axis

Answer

Longitudinal axis.

Question 58

Which option states a benefit of wing washout?

Accepted Answer

At high angles of attack the effectiveness of the aileron is retained as long as possible

Answer

With the washout the form drag reduces at high speeds

Answer

Greater hardness because the wing can withstand more torsion forces

Answer

Structurally the wing is made more rigid against rotation

Question 59

The aerodynamic rudder balance...

Accepted Answer

Reduces the control stick forces.

Answer

Reduces the control surfaces.

Answer

Delays the stall.

Answer

Improves the rudder effectiveness.

Question 60

The right aileron deflects upwards, the left downwards. How does the aircraft react?

Accepted Answer

Rolling to the right, yawing to the left

Answer

Rolling to the left, no yawing

Answer

Rolling to the left, yawing to the right

Answer

Rolling to the right, yawing to the right

Question 61

What leads to a decreased stall speed Vs (IAS)?

Accepted Answer

Decreasing weight

Answer

Lower density

Answer

Lower altitude

Answer

Higher load factor

Question 62

Which statement describes a situation of static stability?

Accepted Answer

An aircraft distorted by external impact will return to the original position

Answer

An aircraft distorted by external impact will tend to an even more deflected position

Answer

An aircraft distorted by external impact will maintain the deflected position

Answer

An aircraft distorted by external impact can return to its original position by rudder input

Question 63

Following a single-wing stall and pitch-down moment, how can a spin be prevented?

Accepted Answer

Rudder opposite lower wing, releasing elevator to build up speed

Answer

Deflect all rudders opposite to lower wing

Answer

Pushing the elevator to build up speed to re-attach airflow on wings

Answer

Pulling the elevator to bring the plane back to normal attitude

Question 64

Point number 5 in the figure indicates which flight state? See figure (PFA-008) Siehe Anlage 5

Accepted Answer

Slow flight

Answer

Best gliding angle

Answer

Inverted flight

Answer

Stall

Exam simulation Principles of Flight (Aeroplane) SPL - Sailplane Pilot License

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