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

Question 1

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

Accepted Answer

Inverted flight

Answer

Slow flight

Answer

Stall

Answer

Best gliding angle

Question 2

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 3

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

Accepted Answer

Separation point

Answer

Transition point

Answer

Stagnation point

Answer

Center of pressure

Question 4

Rotation around the lateral axis is called...

Accepted Answer

Pitching

Answer

Yawing

Answer

Rolling

Answer

Stalling

Question 5

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 6

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 7

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 8

What has to be considered when operating a sailplane with water ballast?

Accepted Answer

It should stay below freezing level

Answer

Best glide angle decreases

Answer

Significant CG shifts

Answer

Best glide speed decreases

Question 9

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

Accepted Answer

Decreasing weight

Answer

Lower density

Answer

Lower altitude

Answer

Higher load factor

Question 10

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 11

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

Accepted Answer

Slow flight

Answer

Best gliding angle

Answer

Inverted flight

Answer

Stall

Question 12

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 13

Rotation around the vertical axis is called...

Accepted Answer

Yawing

Answer

Slipping

Answer

Pitching

Answer

Rolling

Question 14

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 15

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 16

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

Accepted Answer

The stagnation point moves down

Answer

The center of pressure moves down

Answer

The center of pressure moves up

Answer

The stagnation point moves up

Question 17

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 18

How do lift and drag change when approaching a stall condition?

Accepted Answer

Lift decreases and drag increases

Answer

Lift and drag increase

Answer

Lift increases and drag decreases

Answer

Lift and drag decrease

Question 19

Pressure drag, interference drag and friction drag belong to the group of the...

Accepted Answer

Parasite drag

Answer

Main resistance

Answer

Induced drag

Answer

Total drag

Question 20

Which kinds of drag contribute to total drag?

Accepted Answer

Induced drag and parasite drag

Answer

Interference drag and parasite drag

Answer

Induced drag, form drag, skin-friction drag

Answer

Form drag, skin-friction drag, interference drag

Question 21

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 22

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

Accepted Answer

Angle of attack

Answer

Lift angle

Answer

Angle of incidence

Answer

Angle of inclination

Question 23

Pressure compensation on a wing occurs at the...

Accepted Answer

Wing tips

Answer

Leading edge

Answer

Trailing edge

Answer

Wing roots

Question 24

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 25

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 26

What is meant by "ground effect"?

Accepted Answer

Increase of lift and decrease of induced drag close to the ground

Answer

Decrease of lift and increase of induced drag close to the ground

Answer

Increase of lift and increase of induced drag close to the ground

Answer

Decrease of lift and decrease of induced drag close to the ground

Question 27

Which design feature can compensate for adverse yaw?

Accepted Answer

Differential aileron deflection

Answer

Wing dihedral

Answer

Full deflection of the aileron

Answer

Aileron trim

Question 28

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 fixed on the fuselage

Answer

Engine and propeller mounted fixed at the aircraft's nose

Answer

Engine and propeller mounted fixed at the horizontal stabilizer

Question 29

Which effect does a decreasing airspeed have on the induced drag during a horizontal and stable cruise flight?

Accepted Answer

The induced drag will increase

Answer

The induced drag will slightly decrease

Answer

The induced drag will collapse

Answer

The induced drag will remain constant

Question 30

The static pressure of gases work...

Accepted Answer

In all directions

Answer

Only in flow direction

Answer

Only in the direction of the total pressure

Answer

Only vertical to the flow direction

Question 31

If surrounded by airflow (v > 0), any arbitrarily shaped body produces...

Accepted Answer

Drag

Answer

Drag and lift

Answer

Lift without drag

Answer

Constant drag at any speed

Question 32

The center of pressure is the theoretical point of origin of...

Accepted Answer

All aerodynamic forces of the profile

Answer

Only the resulting total drag

Answer

Gravity forces of the profile

Answer

Gravity and aerodynamic forces

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

In which way does the position of the center of pressure move at a positively shaped profile with increasing angle of attack?

Accepted Answer

It moves forward until reaching the critical angle of attack

Answer

It moves to the wing tips

Answer

It moves backward until reaching the critical angle of attack

Answer

It moves forward first, then backward

Question 35

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 36

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 decreases, 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 37

What has to be considered when operating a sailplane equipped with camber flaps?

Accepted Answer

During approach and landing, camber must not be changed from positive to negative

Answer

During approach and landing, camber must not be changed from negative to positive

Answer

During winch launch, camber must be set to full negative

Answer

During winch launch, camber must be set to full positive

Question 38

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 permissible C.G. limits

Answer

Position far back within permissible C.G. limits

Question 39

All aerodynamic forces can be considered to act on a single point. This point is called...

Accepted Answer

Center of pressure

Answer

Center of gravity

Answer

Lift point

Answer

Transition point

Question 40

Differential aileron deflection is used to...

Accepted Answer

Keep the adverse yaw low

Answer

Reduce wake turbulence

Answer

Avoid a stall at low angles of attack

Answer

Increase the rate of descent

Question 41

Where is interference drag generated?

Accepted Answer

At the wing root

Answer

At the ailerons

Answer

At the gear

Answer

Near the wing tips

Question 42

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 43

Which statement concerning the angle of attack is correct?

Accepted Answer

A too large angle of attack may result in a loss of lift

Answer

Increasing the angle of attack results in decreasing lift

Answer

The angle of attack cannot be negative

Answer

The angle of attack is constant throughout the flight

Question 44

What describes "wing loading"?

Accepted Answer

Weight per wing area

Answer

Wing area per weight

Answer

Drag per weight

Answer

Drag per wing area

Question 45

With regard to the forces acting, how can stationary gliding be described?

Accepted Answer

The sum of air forces compensates the gravity force

Answer

The sum of air forces acts along the direction of air flow

Answer

The sum of the air forces acts along with the lift force

Answer

The lift force compensates the drag force

Question 46

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 47

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 48

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 49

What structural item provides lateral stability to an airplane?

Accepted Answer

Wing dihedral

Answer

Vertical tail

Answer

Differential aileron deflection

Answer

Elevator

Question 50

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 51

Which constructive feature has the purpose to reduce steering forces?

Accepted Answer

Aerodynamic rudder balance

Answer

T-tail

Answer

Differential aileron deflection

Answer

Vortex generators

Question 52

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 53

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 54

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 55

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 56

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 57

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

Accepted Answer

Lateral stability by wing dihedral

Answer

Differential aileron deflection

Answer

Directional stability by lift generation

Answer

Longitudinal stability by wing dihedral

Question 58

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 59

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 60

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 61

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

Accepted Answer

Camber line

Answer

Thickness

Answer

Chord

Answer

Chord line

Question 62

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 63

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 64

What is the difference between spin and spiral dive?

Accepted Answer

Spin: stall at inner wing, speed constant; Spiral dive: airflow at both wings, speed increasing rapidly

Answer

Spin: stall at inner wing, speed increasing rapidly; Spiral dive: airflow at both wings, speed constant

Answer

Spin: stall at outer wing, speed constant; Spiral dive: airflow at both wings, speed increasing rapidly

Answer

Spin: stall at outer wing, speed increasing rapidly; Spiral dive: airflow at both wings, speed constant

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

Exam simulation SPL Principles of Flight (Aeroplane) 120 questions on 120 minutes