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Created / Updated	28.04.2022 / 11.05.2022
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What is the "drag polar"?

A polar curve depicting the value of lift coefficient vs. drag coefficient.

A polar autorotation curve.

A chart of the power required.

A graph called "Titus Huber curve" in Poland.

The wing surface increasing devices are:

Fowler flap and the leading edge flaps.

Winglets and trailing edge flaps.

Slots and the split flaps.

Trainling edge flaps and the split flaps.

Devices that move the separation point aft on an airfoil upper surface are called:

Slats.

Trailing edge flaps.

Split flaps.

Fowler flap.

Devices that increace the camber of an airfoil are called:

Leading edge flaps.

Winglets.

Slots.

All answers are correct.

The backward sweep of a wing causes:

Increase in the lateral static stability.

Reduction of the lateral static stability

Reduction of the lateral static stability at positive angles of attack and the increase at negative.

Increase in the lateral static stability at positive angles of attack, and reduction at negative.

Aaerofoil glide ratio:

Depends on the angle of attack.

Is a constant characteristic for the profile and corresponds to the (CL/CD)max.

Always increases when increasing angle of attack.

Always increases when decreasing angle of attack.

Doubling an airflow velocity in a closed tunnel will result in:

A fourfold decrease of static pressure.

A fourfold increase of static pressure.

A twofold increase of static pressure.

A double decrease of static pressure.

Flatter is the name of a phenomenon associated with:

The occurrence of self-existing vibrations.

The formation of the lift force.

The formation of drag force.

Elevator/rudder/aileron reversal.

When air enters a channel with velocity "V" and the channel cross-sectional area changes, that velocity also changes:

The velocity "V" increases at reduced cross-sectional area .

The velocity "V" changes as the static pressure changes.

The velocity "V" does not change at all.

The velocity "V" decreases at reduced cross-sectional area and increases at increased cross-sectional area.

Aerofoil thickness is:

The greatest distance between the upper and the lower airfoil surfaces, perpendicular to its chord.

The average distance between the upper and lower airfoil surfaces.

The distance between the upper and the lower airfoil surfaces at 50% chord line (MAC).

The greatest distance between the upper airfoil surface and the chord line.

The greatest distance between. The bigger air viscosity:

The greater the drag and the thicker the boundary layer.

The smaller the drag and the thinner the boundary layer.

The greater the drag and the thinner the boundary layer.

The smaller the drag and the thicker the boundary layer.

The existence of steerring control surfaces on the airframe causes mainly:

Additional drag caused by slots between those surfaces and wings.

Induced drag.

Wave drag.

Skin friction drag.

What is a "flettner"?

Balance tab.

Anti-balance tab.

Trim tab.

Trimmer .

How does the speed have to change in a balanced turn in order to increase the radious four times (keeping the same bank angle)?

Double.

Increase 4 times.

Increase 8 times.

Reduce 4 times.

What is the name of a tab, which position may be independently changed during the flight?

Trim tab.

Flettner.

Anti-balance tab.

Balance tab.

What is the name of the point at which the airflow changes from laminar to turbulent?

Separation Point.

Stagnation Point.

Pressure Point.

Turbulent point.

What is the name of the graph showing the dependence between coefficients of lift CL and drag CD of the aircraft?

The Drag Polar.

Polar speed curve.

Chart performance.

What is the aircraft's VNE?

Never Exceed Speed.

Cruising speed.

Economic speed.

Optimal speed.

What are the SI units and symbols of mass, length and time?

Kilogram (kg), meter (m) and second (sec).

Kilogram (kg), kilometer (km) and second (sec).

Kilogram (kg), nautical mile (nm) and hour (h).

Ton (t), meter (m) and minutes (min).

What are the SI units and symbols of force, pressure and temperature?

Newton (N), Pascal (Pa), Kelvin (K).

Dyna (D), Bar (b), the degree Celsius (° C).

Pond (Po), atmosphere (at), degree Fahrenheit (° F).

Kilogram-force (kG), atmosphere (at), Kelvin (K).

What is the pressure of 1000 hPa in SI basic units?

100000 N/m.

1000000 N/m.

1000 N/m.

10000 N/m.

How will the radius of a balanced turn change if the speed doubles at the constant bank angle?

Increases 4 times.

Increases 2 times.

Increases 8 times.

Does not change.

How does the density altitude change when the air temperature is higher than ISA ?

Increases.

Slightly decreases.

Does not change.

Decreases inversly proportional to the relative density sigma.

What is the difference between flat and steep spin?

Greater angular change of direction in a flat spin.

Greater angular change of direction in a steep spin.

Higher rate of descent in a flat spin.

During the spin the pilot does not see any difference.

What is the standard ISA air pressure at sea level expressed in mmHg (corresponds to po = 1013.25 hPa)?

760 mm Hg.

800 mm Hg.

750 mm Hg.

860 mm Hg.

What is the name of a ratio of static pressure at any height to the standard ISA pressure at sea level - delta = p/po?

Relative pressure.

Standard pressure.

Modulal pressure.

The Hypocrite's Number.

What is the name of a the ratio of air density at any height to the standard (standard) density at sea level - sigma = rho/ rho o?

The relative air density.

Laplace's constant.

The M/S ratio.

The Piccard's ratio.

What is the name of a ratio of air temperature at any altitude, expressed in Kelvin (K) to the reference temperature at sea level, also expressed in Kelvin (K) - Theta = T / To?

The dimensionless relative temperature.

The absolute temperature.

The Don Pedro's constant.

The d'Amore coefficient.

What is the reference (standard) static pressure at sea level?

After = 101325 N / m = 1013.25 hPa.

After = 100000 N / m = 1000.00 hPa.

After = 111325 N / m = 1113.25 hPa.

After = 100025 N / m = 1000.25 hPa.

What is the reference (standard) air temperature at sea level expressed in Kelvins (K)?

To = 288 K.

To = 258 K.

To = 277 K.

To = 301 K.

What is the reference (standard) air density at sea level expressed in kg/m2?

rho o = 1.2255 kg/m2.

rho o = 1.0000 kg/m2.

rho o = 1.0255 kg/m2.

rho o = 1.2000 kg/m2.

What is the reference (standard) air temperature at sea level expressed in degrees Celsius (deg. C) ?

t = 15 deg. C

t = 10 deg. C

t = 20 deg. C

t = 16.5 deg. C

What relationship exists between the air temperature t expressed in degrees Celsius (deg. C) and temperature T expressed in Kelvins (K)?

T = t + 273.

T = t + 233.

T = t + 283.

T = t + 373.

What are the main features of a thick profile compared to a thinner one at the same velocity of an airflow?

Higher drag and higher lift coefficient.

Higher drag and lower lift coefficient.

Higher drag and the same lift coefficient.

The same drag and higher lift coefficient.

What are the parameters used to describe the physical condition of the air?

Static pressure, temperature and density.

Humidity and dynamic pressure.

Temperature, density and kinematic viscosity.

The content proportions of nitrogen and oxygen.

What are the prefixes of the SI units that mean the multiplication by 10, 100 and 1000?

Deka- (da), hecto-(h), kilo-(k).

Kilo- (k), mega-(m), deca-(da).

The decision-(dc), hecto-(h), mega- (M).

Mega- (M), giga-(G), pico-(p).

What data is needed to calculate the load factor "n" in a balanced turn?

It is enough to know the bank angle.

We need to know the speed and bank angle.

We need to know the turn radius and bank angle.

We need to know the speed, turn radius and bank angle.

What is purpose of "lift ugmentation systems" (flaps, slats, spoilers, etc.)?

They change the aerodynamic coefficients in order to change the aircraft's performance (eg. approach speed).

They increase the maximum lift.

They increase the aicraft's airspeed.

They improve the aircraft's performance and therefore the economy of an aircraft.

What is the name of the instrument that measures the actual height or distance of an aircraft from the ground?

The Radio altimeter (radar).

The pressure altimeter.

The optical rangefinder.

The DME.

One of the measurement of dynamic stability of an object (airplane, helicopter, glider, hang-glider, etc.) is so called "half-time". What is it?

The time that elapses from the disturbance from equilibrium until it decreases in half (50%).

The half-period time of fugoidal flucutations caused by the disturbance.

Absolute stability

Absolute instability.

PL080 - Principles of Flight PPL(A)

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