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

Question 1

Stabilization around the lateral axis during cruise is achieved by the...

Accepted Answer

Horizontal stabilizer

Answer

Wing flaps

Answer

Ailerons

Answer

Vertical rudder

Question 2

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 3

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 4

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 5

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 6

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 7

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 8

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 9

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 10

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 11

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 12

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 13

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 14

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 15

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

Accepted Answer

Chord line

Answer

Profile thickness

Answer

Chord

Answer

Angle of attack

Question 16

What pattern can be found at the stagnation point?

Accepted Answer

Streamlines are divided into airflow above and below the profile

Answer

The boundary layer starts separating on the upper surface of the profile

Answer

All aerodynamic forces can be considered as attacking at this single point

Answer

The laminar boundary layer changes into a turbulent boundary layer

Question 17

"Longitudinal stability" is referred to as stability around which axis?

Accepted Answer

Lateral axis

Answer

Propeller axis

Answer

Longitudinal axis

Answer

Vertical axis

Question 18

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 centre of pressure

Answer

The transition point and the separation point

Answer

The transition point and the centre of pressure

Question 19

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

Accepted Answer

The centre of pressure moves aft

Answer

The centre of pressure moves forward

Answer

The stagnation point moves down

Answer

The stagnation point remains constant

Question 20

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

Centre of pressure

Question 21

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

Accepted Answer

Stagnation point

Answer

Centre of pressure

Answer

Separation point

Answer

Transition point

Question 22

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

Question 23

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 24

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 25

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 26

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

Accepted Answer

Nose-down position

Answer

Neutral position

Answer

Nose-up position

Answer

Laterally trimmed

Question 27

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

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 28

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 29

In which way does the position of the centre 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 30

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 31

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 32

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 33

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 34

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 35

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 36

How does aircraft weight affect the critical angle of attack?

Accepted Answer

Is independent of the weight

Answer

Decreases with forward centre of gravity position

Answer

Changes with increasing weight

Answer

Increases with backward centre of gravity position

Question 37

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 38

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 39

Rotation around the lateral axis is called...

Accepted Answer

Pitching

Answer

Yawing

Answer

Rolling

Answer

Stalling

Question 40

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 41

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 42

Rotation around the vertical axis is called...

Accepted Answer

Yawing

Answer

Slipping

Answer

Pitching

Answer

Rolling

Question 43

Extending airbrakes results in ...

Accepted Answer

More drag and less lift

Answer

Less drag and more lift

Answer

More drag and more lift

Answer

Less drag and less lift

Question 44

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

Accepted Answer

Camber line

Answer

Thickness

Answer

Chord

Answer

Chord line

Question 45

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 46

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 47

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 48

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

Accepted Answer

Only correct loading can assure a correct and safe centre of gravity position

Answer

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

Answer

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

Answer

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

Question 49

The pressure compensation between wing upper and lower surfaces 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 50

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 51

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 52

Stability around which axis is mainly influenced by the centre of gravity's longitudinal position?

Accepted Answer

Lateral axis

Answer

Longitudinal axis

Answer

Gravity axis

Answer

Vertical axis

Question 53

What is the function of the static rudder balance?

Accepted Answer

To prevent control surface flutter

Answer

To trim the controls almost without any force

Answer

To increase the control stick forces

Answer

To limit the control stick forces

Question 54

At stationary glide and the same mass, what is the difference when using a thick airfoil 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 55

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 56

The elevator moves an aeroplane around the...

Accepted Answer

Lateral axis

Answer

Vertical axis

Answer

Longitudinal axis

Answer

Elevator axis

Question 57

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 58

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 59

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 60

During approach 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 to 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 61

The centre 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 62

Which point on the aerofoil is represented by number 3? See figure (PFA-009)

Accepted Answer

Transition point

Answer

Stagnation point

Answer

Separation point

Answer

Centre of pressure

Question 63

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 64

What describes "wing loading"?

Accepted Answer

Weight per wing area

Answer

Wing area per weight

Answer

Drag per weight

Answer

Drag per wing area

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

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