Principles of Flight Flashcards
Compared to trailing edge flaps, leading edge devices like Slots… (1,00 P.)
reduce the critical angle of attack at a given speed.
allow higher speeds at take-off and landing.
produce less drag while allowing a higher angle of attack.
increase the camber and allow a lower angle of attack.
produce less drag while allowing a higher angle of attack.
Stabilization around the lateral axis during cruise is achieved by the… (1,00 P.)
horizontal stabilizer.
airlerons.
wing flaps.
vertical rudder.
horizontal stabilizer.
Flying with speeds higher than the never-exceed-speed (vNE) may result in… (1,00 P.)
too high total pressure resulting in an unusable airspeed indicator.
flutter and mechanically damaging the wings.
an increased lift-to-drag ratio and a better glide angle.
reduced drag with increased control forces.
flutter and mechanically damaging the wings.
What effects typically result from propeller icing? (1,00 P.)
Reduced power output, decreasing RPM.
Increased power output, decreasing RPM.
Increased power output, increasing RPM.
Reduced power output, increasing RPM.
Reduced power output, decreasing RPM.
During a straight and steady climb, which force acts addionally, and in the same direction as the drag force, resulting in more power required for climb than for horizontal flight? (1,00 P.)
A component of the weight force along the rearward flight path.
The vertical component of the weight force.
A component of the thrust along the rearward flightpath.
A component of the lift force along the forward flightpath.
A component of the weight force along the rearward flight path.
The static pressure of gases work… (1,00 P.)
only vertical to the flow direction.
only in the direction of the total pressure.
in all directions.
only in flow direction.
in all directions.
Bernoulli’s equation for frictionless, incompressible gases states that… (1,00 P.)
static pressure = total pressure + dynamic pressure.
total pressure = dynamic pressure - static pressure.
dynamic pressure = total pressure + static pressure.
total pressure = dynamic pressure + static pressure.
total pressure = dynamic pressure + static pressure.
If surrounded by airflow (v>0), any arbitrarily shaped body produces… (1,00 P.)
lift without drag.
drag and lift.
constant drag at any speed.
drag.
drag.
All aerodynamic forces can be considered to act on a single point. This point is called… (1,00 P.)
center of gravity.
center of pressure.
lift point.
transition point.
center of pressure.
The center of pressure is the theoretical point of origin of… (1,00 P.)
only the resulting total drag.
all aerodynamic forces of the profile.
gravity forces of the profile.
gravity and aerodynamic forces.
all aerodynamic forces of the profile.
Number 2 in the drawing corresponds to the… See figure (PFA-010) (1,00 P.)
chord line.
chord.
angle of attack.profile
thickness.
https://cloud.wafa-sadri.de/s/Ns4pt7jRYLfTKQ6
chord
Number 3 in the drawing corresponds to the…
See figure (PFA-010) (1,00 P.)
chord.
thickness.
camber line.
chord line.
https://cloud.wafa-sadri.de/s/Ns4pt7jRYLfTKQ6
camber line.
The angle of attack is the angle between… (1,00 P.)
the undisturbed airflow and the longitudinal axis of an aeroplane.
the chord line and the longitudinal axis of an aeroplane.
the chord line and the oncoming airflow.
the wing and the fuselage of an aeroplane.
the chord line and the oncoming airflow.
The ratio of span and mean chord length is referred to as… (1,00 P.)
trapezium shape.
tapering.
aspect ratio.
wing sweep.
aspect ratio.
Which point on the aerofoil is represented by number 3? See figure (PFA-009) (1,00 P.)
Separation point
Center of pressure
Stagnation point
Transition point
https://cloud.wafa-sadri.de/s/Ns4pt7jRYLfTKQ6
Transition point
Which point on the aerofoil is represented by number 3? See figure (PFA-009) (1,00 P.)
? Separation point
? Center of pressure
? Stagnation point
? Transition point
Which point on the aerofoil is represented by number 4?
See figure (PFA-009) (1,00 P.)
Center of pressure
Separation point
Transition point
Stagnation point
https://cloud.wafa-sadri.de/s/Ns4pt7jRYLfTKQ6
Separation point
Wing tip vortex development begins during which phase of flight? (1,00 P.)
As soon as the aircraft starts moving
While setting take-off power during take-off run
While setting flaps to lower position
When lift is being generated during rotation
When lift is being generated during rotation
Which point on the aerofoil is represented by number 1? See figure (PFA-009) (1,00 P.)
Transition point
Stagnation point
Center of pressure
Separation point
https://cloud.wafa-sadri.de/s/Ns4pt7jRYLfTKQ6
Stagnation point
What pattern can be found at the stagnation point? (1,00 P.)
The boundary layer starts separating on the upper surface of the profile
The laminar boundary layer changes into a turbulent boundary layer
All aerodynamic forces can be considered as attacking at this single point
Streamlines are divided into airflow above and below the profile
Streamlines are divided into airflow above and below the profile
What pressure pattern can be observed at a lift-generating wing profile at positive angle of attack? (1,00 P.)
Low pressure is created above, higher pressure below the profile
High pressure is created above, lower pressure below the profile
Pressure above remains unchanged, higher pressure is created below the profile
Pressure below remains unchanged, lower pressure is created above the profile
Low pressure is created above, higher pressure below the profile
The position of the the center of pressure at a positively shaped profile… (1,00 P.)
moves to the leading edge while the angle of attack becomes smaller.
is located at approximately 25% of the chord, measured from the leading edge.
moves to the trailing edge while the angle of attack becomes smaller.
does not move since it is independent of the angle of attack.
moves to the trailing edge while the angle of attack becomes smaller.
In which way does the position of the center of pressure move at a positively shaped profile with increasing angle of attack? (1,00 P.)
It moves backward until reaching the critical angle of attack
It moves forward first, then backward
It moves forward until reaching the critical angle of attack
It moves to the wing tips
It moves forward until reaching the critical angle of attack
Which statement about lift and angle of attack is correct? (1,00 P.)
Too large angles of attack can lead to an exponential increase in lift
Increasing the angle of attack results in less lift being generated by the aerofoil
Increasing the angle of attack too far may result in a loss of lift and an airflow separation
Decreasing the angle of attack results in more drag being generated by the aerofoil
Increasing the angle of attack too far may result in a loss of lift and an airflow separation
Which statement about the airflow around an aerofoil is correct if the angle of attack increases? (1,00 P.)
The stagnation point moves down
The center of pressure moves down
The center of pressure moves up
The stagnation point moves up
The stagnation point moves down
Which statement about the airflow around an aerofoil is correct if the angle of attack decreases? (1,00 P.)
The center of pressure moves aft
The stagnation point remains constant
The stagnation point moves down
The center of pressure moves forward
The center of pressure moves aft
The angle (alpha) shown in the figure is referred to as…
See figure (PFA-003)
DoF: direction of airflow (1,00 P.)
lift angle.
angle of incidence.
angle of inclination.
angle of attack.
angle of attack.
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… (1,00 P.)
aerodynamic washout.
arrow shape.
V-form.
geometric washout.
geometric washout.
Which option states a benefit of wing washout? (1,00 P.)
Structurally the wing is made more rigid against rotation
With the washout the form drag reduces at high speeds
Greater hardness because the wing can withstand more torsion forces
At high angles of attack the effectiveness of the aileron is retained as long as possible
At high angles of attack the effectiveness of the aileron is retained as long as possible
Which statement concerning the angle of attack is correct? (1,00 P.)
The angle of attack cannot be negative
Increasing the angle of attack results in decreasing lift
The angle of attack is constant throughout the flight
A too large angle of attack may result in a loss of lift
A too large angle of attack may result in a loss of lift
When increasing the airflow speed by a factor of 2 while keeping all other parameters constant, how does the parasite drag change approximately? (1,00 P.)
It decreases by a factor of 2
It increases by a factor of 2
It decreases by a factor of 4
It increases by a factor of 4
It increases by a factor of 4
The drag coefficient… (1,00 P.)
increases with increasing airspeed.
is proportional to the lift coefficient.
cannot be lower than a non-negative, minimal value.
may range from zero to an infinite positive value.
cannot be lower than a non-negative, minimal value.
Pressure compensation on an wing occurs at the… (1,00 P.)
wing roots.
wing tips.
trailing edge.
leading edge.
wing tips.
Which of the following options is likely to produce large induced drag? (1,00 P.)
Large aspect ratio
Tapered wings
Small aspect ratio
Low lift coefficients
Small aspect ratio
Which parts of an aircraft mainly affect the generation of induced drag? (1,00 P.)
the front part of the fuselage.
the wing tips.
the lower part of the gear.
the outer part of the ailerons.
the wing tips.
Where is interference drag generated? (1,00 P.)
At the wing root
At the ailerons
At the the gear
Near the wing tips
At the wing root
Which curve represents the induced drag?
See Appendix (PFA-011) (1,00 P.)
1
4
2
3
1
Pressure drag, interference drag and friction drag belong to the group of the… (1,00 P.)
induced drag.
parasite drag.
main resistance.
total drag.
parasite drag.
What kind of drag is NOT part of the parasite drag? (1,00 P.)
Interference drag
Skin-friction drag
Induced drag
Form drag
Induced drag
How do induced drag and parasite drag change with increasing airspeed during a horizontal and stable cruise flight? (1,00 P.)
Induced drag decreases and parasite drag increases
Parasite drag decreases and induced drag increases
Parasite drag decreases and induced drag decreases
Induced drag increases and parasite drag increases
Induced drag decreases and parasite drag increases
Which of the listed wing shapes has the lowest induced drag? (1,00 P.)
Elliptical shape
Double trapezoidal shape
Rectangular shape
Trapezoidal shape
Elliptical shape
Which effect does a decreasing airspeed have on the induced drag during a horizontal and stable cruise flight? (1,00 P.)
The induced drag will increase
The induced drag will collapse
The induced drag will remain constant
The induced drag will slightly decrease
The induced drag will increase
Which statement about induced drag during the horizontal cruise flight is correct? (1,00 P.)
Induced drag has a minimum at a certain speed and increases at higher as well as lower speeds
Induced drag has a maximum at a certain speed and decreases at higher as well as lower speeds
Induced drag increases with increasing airspeed
Induced drag decreases with increasing airspeed
Induced drag decreases with increasing airspeed
In which mentioned situation is the total drag at its minimum? (1,00 P.)
Induced drag is twice as much as parasite drag
Parasite drag is twice as much as induced drag
Parasite drag is equal to induced drag
Induced drag is smaller than parasite drag
Parasite drag is equal to induced drag
Which kinds of drag contribute to total drag? (1,00 P.)
Form drag, skin-friction drag, interference drag
Interference drag and parasite drag
Induced drag, form drag, skin-friction drag
Induced drag and parasite drag
Induced drag and parasite drag
How do lift and drag change when approaching a stall condition? (1,00 P.)
Lift and drag decrease
Lift and drag increase
Lift decreases and drag increases
Lift increases and drag decreases
Lift decreases and drag increases
In case of a stall it is important to… (1,00 P.)
increase the bank angle and reduce the speed.
increase the angle of attack and increase the speed.
decrease the angle of attack and increase the speed.
increase the angle of attack and reduce the speed.
decrease the angle of attack and increase the speed.
During a stall, the lift… (1,00 P.)
decreases and drag increases.
increases and drag decreases.
increases and drag increases.
decreases and drag decreases.
decreases and drag increases.
The critical angle of attack… (1,00 P.)
changes with increasing weight.
decreases with forward center of gravity position.
is independent of the weight.
increases with backward center of gravity position.
is independent of the weight.
What leads to a decreased stall speed Vs (IAS)? (1,00 P.)
Lower altitude
Lower density
Higher load factor
Decreasing weight
Decreasing weight
The stall warning will be activated just before reaching which speed? (1,00 P.)
VNE
VS
VX
VR
VS
In motorplanes the stall warning is usually activated by a change of… (1,00 P.)
the center of gravity.
the transition point.
the center of pressure.
the stagnation point.
the stagnation point.
How should the pilot react to an engaged stall warning? (1,00 P.)
Pull the elevator, increase power
Pull the elevator, decrease power
Push the elevator, increase power
Raise the nose to decrease airspeed
Push the elevator, increase power
Which statement regarding a spin is correct? (1,00 P.)
During recovery the ailerons should be kept neutral
Only very old aeroplanes have a risk of spinning
During recovery the ailerons should be crossed
During the spin the speed constantly increases
During recovery the ailerons should be kept neutral
When extending the flaps for landing at constant angle of attack, in which way does the lift coefficient change far before reaching the maximum lift coefficient? (1,00 P.)
It decreases
It is not possible to define
It increases
It remains constant
It increases
With regard to flaps, which of the following options provides a lift-increasing effect? (1,00 P.)
Decreasing the angle of attack
Increasing the aerofoil camber
Decreasing the form drag
Lowering the induced drag
Increasing the aerofoil camber
Which factor can be changed by deploying flaps for landing? (1,00 P.)
The position of the center of gravity
The effectiveness of the ailerons
The twist effect of the engine
The trim condition
The trim condition
What is the principle of a Fowler flap? (1,00 P.)
A profile-like flap is extended from the trailing edge of the wing
A flap from the rear bottom side of the wing is folded down
At high angles of attack a part of the leading edge lifts
The rear part of the wing is folded down
A profile-like flap is extended from the trailing edge of the wing
A take-off with flaps in take-off position causes… (1,00 P.)
an increased rate of climb.
an increased acceleration.
a shortening of the take-off run.
a decrease in drag.
a shortening of the take-off run.
Provided that no other procedure is described in the Aircraft Operating Handbook, after increasing the engine power in a go-around, the flaps may… (1,00 P.)
not be operated up to the minimum safe altitude.
be retracted to a middle position.
be fully retracted without any delay.
remain fully extended until reaching the traffic pattern.
be retracted to a middle position.
How do lift and drag change when setting flaps to a lower position? (1,00 P.)
Lift increases, drag decreases
Lift increases, drag increases
Lift decreases, drag decreases
Lift decreases, drag increases
Lift increases, drag increases
The laminar boundary layer on the aerofoil is located between… (1,00 P.)
the transition point and the separation point.
the stagnation point and the transition point.
the transition point and the center of pressure.
the stagnation point and the center of pressure.
the stagnation point and the transition point.
What types of boundary layers can be found on an aerofoil? (1,00 P.)
Laminar layer at the leading wing areas, turbulent boundary layer at the trailing areas
Turbulent boundary layer along the complete upper surface with separated airflow
Turbulent layer at the leading wing areas, laminar boundary layer at the trailing areas
Laminar boundary layer along the complete upper surface with non-separated airflow
Laminar layer at the leading wing areas, turbulent boundary layer at the trailing areas
How does a laminar boundary layer differ from a turbulent boundary layer? (1,00 P.)
The laminar boundary layer produces lift, the turbulent boundary layer produces drag
The turbulent boundary layer is thicker and provides less skin-friction drag
The laminar boundary layer is thinner and provides more skin-friction drag
The turbulent boundary layer can follow the airfoil camber at higher angles of attack
The turbulent boundary layer can follow the airfoil camber at higher angles of attack
What structural item provides lateral stability to an airplane? (1,00 P.)
Differential aileron deflection
Wing dihedral
Vertical tail
Elevator
Wing dihedral
Which statement describes a situation of static stability? (1,00 P.)
An aircraft distorted by external impact will tend to an even more deflected position
An aircraft distorted by external impact will return to the original position
An aircraft distorted by external impact can return to its original position by rudder input
An aircraft distorted by external impact will maintain the deflected position
An aircraft distorted by external impact will return to the original position
Which constructive feature is shown in the figure?
See figure (PFA-006)
L: Lift (1,00 P.)
Longitudinal stability by wing dihedral
Lateral stability by wing dihedral
Differential aileron deflection
Directional stability by lift generation
https://cloud.wafa-sadri.de/s/ZbzBP755yqdegZE
Lateral stability by wing dihedral
“Longitudinal stability” is referred to as stability around which axis? (1,00 P.)
Propeller axis
Vertical axis
Longitudinal axis
Lateral axis
Lateral axis
Stability around which axis is mainly influenced by the center of gravity’s longitudinal position? (1,00 P.)
Vertical axis
Longitudinal axis
Gravity axis
Lateral axis
Lateral axis
What structural item provides directional stability to an airplane? (1,00 P.)
Differential aileron deflection
Large vertical tail
Wing dihedral
Large elevator
Large vertical tail
Rotation around the vertical axis is called… (1,00 P.)
rolling.
pitching.
yawing.
slipping.
yawing
Rotation around the lateral axis is called… (1,00 P.)
rolling.
stalling.
yawing.
pitching.
pitching
The critical angle of attack… (1,00 P.)
increases with a front centre of gravity.
decreases with a rear centre of gravity.
is changed by different aircraft weights.
is not changed by different aircraft weights.
is not changed by different aircraft weights.
In straight and level flight with constant performance of the engine, the angle of attack at the wing is… (1,00 P.)
greater than in a climb.
greater than at take-off.
smaller than in a descent.
smaller than in a climb.
smaller than in a climb.
What is the function of the horizontal tail (among other things)? (1,00 P.)
To stabilise the aeroplane around the lateral axis
To initiate a curve around the vertical axis
To stabilise the aeroplane around the longitudinal axis
To stabilise the aeroplane around the vertical axis
To stabilise the aeroplane around the lateral axis
The elevator deflection during take-off rotation… (1,00 P.)
is increased for a front centre of gravity.
is increased for a rear centre of gravity.
is increased at high speeds.
is independent of the speed.
is increased for a front centre of gravity.
The elevator moves an aeroplane around the… (1,00 P.)
lateral axis.
elevator axis.
longitudinal axis.
vertical axis.
lateral axis.
What has to be considered with regard to the center of gravity position? (1,00 P.)
The center of gravity’s position can only be determined during flight.
Only correct loading can assure a correct and safe center of gravity position.
By moving the elevator trim tab, the center of gravity can be shifted into a correct position.
By moving the aileron trim tab, the center of gravity can be shifted into a correct position.
Only correct loading can assure a correct and safe center of gravity position.
Rudder deflections result in a turn of the aeroplane around the… (1,00 P.)
rudder axis.
lateral axis.
vertical axis.
longitudinal axis.
vertical axis.
Deflecting the rudder to the left causes… (1,00 P.)
pitching of the aircraft to the right.
yawing of the aircraft to the right.
yawing of the aircraft to the left.
pitching of the aircraft to the left.
yawing of the aircraft to the left.
What is the advantage of differential aileron movement? (1,00 P.)
The ratio of the drag coefficient to lift coefficient is increased
The adverse yaw is higher
The drag of the downwards deflected aileron is lowered and the adverse yaw is smaller
The total lift remains constant during aileron deflection
The drag of the downwards deflected aileron is lowered and the adverse yaw is smaller
Which design feature can compensate for adverse yaw? (1,00 P.)
Wing dihedral
Full deflection of the aileron
Aileron trim
Differential aileron defletion
Differential aileron defletion
Differential aileron deflection is used to… (1,00 P.)
keep the adverse yaw low.
avoid a stall at low angles of attack.
increase the rate of descent.
reduce wake turbulence.
keep the adverse yaw low.
The right aileron deflects upwards, the left downwards. How does the aircraft react? (1,00 P.)
Rolling to the left, no yawing
Rolling to the right, yawing to the right
Rolling to the right, yawing to the left
Rolling to the left, yawing to the right
Rolling to the right, yawing to the left
The aerodynamic rudder balance… (1,00 P.)
improves the rudder effectiveness.
reduces the control surfaces.
reduces the control stick forces.
delays the stall.
reduces the control stick forces.
Which constructive feature has the purpose to reduce stearing forces? (1,00 P.)
T-tail
Vortex generators
Differential aileron deflection
Aerodynamic rudder balance
Aerodynamic rudder balance
What is the function of the static rudder balance? (1,00 P.)
To trim the controls almost without any force
To increase the control stick forces
To limit the control stick forces
To prevent control surface flutter
To prevent control surface flutter
During cruise flight with constant power setting, an aircraft shows a permanent tendency to raise the nose.
How can this tendency be eliminated? (1,00 P.)
By deflecting the elevator trim tab upwards
By shifting the center of gravity backwards
By elevator deflection upwards
By deflecting the elevator trim tab downwards
By deflecting the elevator trim tab upwards
The trim tab at the elevator is defelected upwards.
In which position is the corresponding indicator? (1,00 P.)
Neutral position
Nose-up position
Nose-down position
Laterally trimmed
Nose-down position
What describes “wing loading”? (1,00 P.)
Drag per wing area
Drag per weight
Wing area per weight
Weight per wing area
Weight per wing area
Through which factor listed below does the load factor increase during cruise flight? (1,00 P.)
A forward centre of gravity
Higher aeroplane weight
An upward gust
Lower air density
An upward gust
Which statement regarding the “constant-speed propeller” is correct? (1,00 P.)
The propeller keeps the airspeed constant
The pitch of the propeller rises with higher speeds
The RPM decreases with lower speeds
The set RPM is kept constant by the motor power (MAP)
The pitch of the propeller rises with higher speeds
The change in pitch at a propeller blade from the root to the tip ensures… (1,00 P.)
that the most thrust is produced at the blade tip.
that the most thrust is produced at the blade root.
a nearly constant load by a constant effective angle of attack over the entire length of the blade.
the largest possible angle of attack at the blade tip.
a nearly constant load by a constant effective angle of attack over the entire length of the blade.
After an engine failure, the windmilling propeller… (1,00 P.)
generates neither thrust nor drag.
has a greater pitch in feathered position.
generates drag rather than thrust.
improves the properties of the glide.
generates drag rather than thrust.
During a descent at idle power with constant speed, the propeller lever is moved backwards.
How do the propeller pitch and sink rate change? (1,00 P.)
Propeller pitch is increased, sink rate is increased
Propeller pitch is increased, sink rate is decreased
Propeller pitch is decreased, sink rate is increased
Propeller pitch is decreased, sink rate is decreased
Propeller pitch is increased, sink rate is decreased
Point number 1 in the figure indicates which flight state? See figure (PFA-008) (1,00 P.)
Stall
Inverted flight
Best gliding angle
Slow flight
https://cloud.wafa-sadri.de/s/3jFAajBE6myiSoL
Inverted flight
Point number 5 in the figure indicates which flight state?
See figure (PFA-008) (1,00 P.)
Best gliding angle
Slow flight
Stall
Inverted flight
https://cloud.wafa-sadri.de/s/3jFAajBE6myiSoL
Slow flight
The bank in a two-minute turn (rate one turn) depends on the… (1,00 P.)
weight.
wind.
load factor.
TAS.
TAS.
In a co-ordinated turn, how is the relation between the load factor (n) and the stall speed (Vs)? (1,00 P.)
n is smaller than 1, Vs is greater than in straight and level flight.
n is greater than 1, Vs is greater than in straight and level flight.
n is smaller than 1, Vs is smaller than in straight and level flight.
n is greater than 1, Vs is smaller than in straight and level flight.
n is greater than 1, Vs is greater than in straight and level flight.
How is the balance of forces affected during a turn? (1,00 P.)
Lift force must be increased to compensate for the sum of centrifugal and gravitational force
The net force results from superposition of gravity and centripetal forces
The horizontal component of the lift force during a turn is the centrifugal force
A lower lift force compensates for a lower net force as compared to level flight
Lift force must be increased to compensate for the sum of centrifugal and gravitational force
The pressure compensation between wind upper and lower surface results in … (1,00 P.)
laminar airflow by wing tip vortices.
profile drag by wing tip vortices.
induced drag by wing tip vortices.
lift by wing tip vortices.
induced drag by wing tip vortices.
What is meant by “ground effect”? (1,00 P.)
Increase of lift and increase of induced drag close to the ground
Decrease of lift and increase of induced drag close to the ground
Decrease of lift and decrease of induced drag close to the ground
Increase of lift and decrease of induced drag close to the ground
Increase of lift and decrease of induced drag close to the ground
What is the diffeence between spin and spiral dive? (1,00 P.)
Spin: stall at outer wing, speed constant;
Spiral dive: airflow at both wings, speed increasing rapidly
Spin: stall at inner wing, speed constant;
Spiral dive: airflow at both wings, speed increasing rapidly
Spin: stall at outer wing, speed increasing rapidly;
Spiral dive: airflow at both wings, speed constant
Spin: stall at inner wing, speed increasing rapidly;
Spiral dive: airflow at both wings, speed constant
Spin: stall at inner wing, speed constant;
Spiral dive: airflow at both wings, speed increasing rapidly
