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Created / Updated	28.04.2022 / 11.05.2022
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Are cambered aerofoils much more "sensitive" to contamination than laminar profiles?

No.

No, but only for small angles of attack.

Yes.

Yes, but only at high angles of attack.

To prevent airleron flutter it is necessary to:

Increase the bending rigidity of the wing and apply mass balance to the aileron.

Apply aerodynamic balance - move the wing CoG closest to the axis of torsion.

Apply balance tab and increase the torsional rigidity of the wing.

Apply anti-balance tab and aileron mass balance.

To prevent bending-torsional flutter it is necessary to:

Increase the torsional rigidity of the wing and move the wing CoG closest to the axis of torsion.

Apply aerodynamic balance - move the wing CoG closest to the axis of torsion.

Apply balance tab and increase the torsional rigidity of the wing.

Apply anti-balance tab and aileron mass balance.

To prevent airleron reversal it is necessary to:

Increase the torsional rigidity of the wing.

Apply aerodynamic ballance.

Apply balance tab.

Apply anti-balance tab.

To prevent buffeting it is necessary to:

Use the T-tail configuration and carefully design wing-fuselage joint.

Use the T-tail configuration and trim tab.

Use trim tab and carefully design wing-fuselage joint.

Increase the bending and torsional rigidity of the tailplane.

An aerodynamic leading edge is a line joining the points of airfoil where:

Airflow velocity is zero and the pressure equals stagnation pressure.

Airflow velocity is zero.

The pressure is greater than the stagnation pressure.

Airflow velocity is zero and the pressure is at its minimum value.

Lack of airlerons mass balance during high-speed flight is a direct cause of:

Aileron flutter.

Bending- torsional flutter.

Airleron reversal.

Wing torsional divergence.

Buffeting means:

Shaking of control surfaces.

Bending- torsional vibrations.

Aileron flatter.

Tailplane flatter.

An object moves with the speed V on a circular track. A double increase of the object's speed will cause the following:

Angular speed "Omega" doubles - centripetal accelaration "ar" increases four times.

Angular speed "Omega" doubles - centripetal accelaration "ar" doubles.

Angular speed "Omega" increases four times - centripetal accelaration "ar" increases four times.

Angular speed "Omega" increases four times - centripetal accelaration "ar" doubles.

An object moves with the speed V on a circular track. A double increase of the track's radius will cause the following:

Angular speed "Omega" decreases by half - the object's full period path doubles - centripetal accelaration "ar" decreases by half.

Angular speed "Omega" decreases by half - the object's full period path decreases by half - centripetal accelaration "ar" decreases by half.

Angular speed "Omega" decreases by half - the object's full period path doubles - centripetal accelaration "ar" doubles.

Angular speed "Omega" decreases by half - the object's full period path double - centripetal accelaration "ar" stays constant.

An object moves with the speed "V" on a circular track with radius "R". The resultant acceleration vector is always directed:

Towards the track center.

Towards the outside of the track.

Tangent to the circle.

Static pressure at the separation point (change from laminar flow to turbulent flow) is:

Minimal on the upper surface and maximal on the bottom surface.

Maximal on the upper surface and mnimal at the bottom surface.

Minimal on the upper surface ana minimal on the bottom surface.

Maximal on the upper surface and maximal on the bottom surface.

What does "the universal gas law" mean?

Relation between static pressure, density, temperature and gas constant p=rho*g*R*T [Pa].

Relation between the air pressure and its temperature

Equation of a balance between the air pressure and its humidity.

Equation of the balance between the air pressure and earth acceleration

What dose the term " controllability " of a flying object ( plane, helicopter, glider, hang-glider etc) mean?

Ability of the object to "respond" to control impulses induced by the pilot.

Assurance that acrobatic exercises are permitted.

Assurance that the object's performance is as designed.

Assurance that the object is statically and dynamically stable.

What does "stagnation pressure" mean?

The difference between the dynamic and static pressure.

The highest measured pressure.

The lowest measured pressure.

The sum of a dynamic and static pressure.

What is a "laminar flow"?

Undisturbed flow from the leading edge to the separation point.

Undisturbed flow along the entire chord, with air streams adhering to the profile.

Disturbed (turbulent) flow along the entire profile chord.

Disturbed (turbulent) flow along the entire profile chord, with maintained stream adherence to the profile.

What does the aircraft (helicopter, glider, etc.) "absolute ceiling" mean?

The highest theoretical altitude that the aircraft is able to climb.

An altitude calculated in the design project of an aircraft.

The altitude at which the aircraft still maintains the climbing ability of 0,5m/s.

The altitude of the atmospere surrounding the Earth.

What does "static stability" of an object mean? (aircraft, helicopter, grinder, hang-grinder etc.)

A tendency (in a form of force or a moment) to return to the former equilibrium after a disturbance.

Balance condition.

No reaction to balance disturbance.

Object static fluctuations around the lateral axis.

What does "airfoil Center of Pressure" mean?

An imaginable point on the chord of an aerofoil at with the resultant force (of all aerodynamic forces) act.

A drag force application point.

A point at which the pressure value is average.

A center of the profile chord line.

What does the boundary layer mean"

A layer of air flowing around an arbitrary aircraft element in which the stream velocity changes from zero to free stream velocity.

A turbulent air region in the area of fuslage and other aircraft elements joints.

A part of an airstream flowing a part of aircraft with A-type flow.

A part of an airstream which changes from laminar to A-type flow.

What is an "Aspect Ratio" of an aircraft or glider wing (or a propeller blade)?

The ratio of wingspan to average chord length.

The ratio of wing or blade length to the chord length at the base of it.

The ratio of wingspan (rotor diameter) to the aircraft (helicopter) length.

The ratio of mean aerodynamic chord to the wing or blade length.

What is the elevation of the airport?

The physical elevation (altitude) of an airport apron above mean sea level according to ISA.

The facade of an airport building.

The surface of the runway.

The slope of the main runway surface.

What is the air density?

An air mass contained in a volume of 1m3.

The opposite of the atmospheric viscosity.

The number of molecules of oxygen and nitrogen in a 1cm3 volume.

The weight of 1 m3 air.

What is this the International Standard Atmosphere (ISA)?

A set of values considered as standard of static pressure (p), temperatures (t/T) and the air density (rho) at different heights.

A set of intormation about atmospheric parameters held at the UN headquarters in New York.

A set of intormation about atmospheric parameters held at the ICAO headquarters in Montreal.

A collection of air chemical composition at different heights.

What is it a pressure altitude above the airport level?

A reading of a pressure altimeter which is set to an airport pressure QFE.

A reading of a pressure altimeter which is set to sea level pressure QNH.

A reading of a radio altimeter.

The airport elevation.

What is pressure altitude above sea level?

A reading of a pressure altimeter when it is set to the current sea level pressure QNH.

The airport elevation.

A reading of a pressure altimeter when it is set to the current airport pressure QFE.

A reading of a radio altimeter.

What is density altitude?

Theoretical height, where the air density is equal to the standard density according to ISA.

The height according to international standard atmosphere (ISA).

The airport elevation height corrected for the current air density.

The pressure altitude corrected for humidity.

What is the standard height?

A reading of a pressure altimeter when it is set to the standard value at sea level (QNH) this is 1013.25 hPa or 760 mm Hg.

A reading of a standard radio altimeter.

The airport elevation.

Density altitude, corrected for ambient temperature.

Is there any connection between air static pressure (p), the absolute temperature (T) and density (rho)? Czy między ciśnieniem statycznym powietrza p, jego temperaturą bezwzględną T i gęstością rho; istnieje jakiś związek?

Yes, expressed as the Universal Gas Law p=rho*g*R*T [Pa], where g is the gravity constant g = 9.81 m/s2 and gas constant R = 29.2746 m/K.

Yes, expressed in Mallets Law p=R*g*rho*dT [Pa], where g is the gravity constant g = 9.81 m/s2 and air gas constant R = 29.2746 m/K.

Yes, expressed as a Crakow's form f [A, g, p, rho, T]

There is no connection

Does the object (aircraft, helicopter, glider, hang-glider, etc.) statically unstable can be dynamically stable?

No.

Yes.

Static stability is not important for the dynamic stability.

Fixed-wing aircraft - yes, Rotorcraft - no.

Does increase of stability affect controlability?

Yes, controlability decreases.

Yes, controlability increses.

No, changes of stability do not affect controlability.

Yes, at large angles of attack the controlability increases and at small decreases.

What is the difference between static stability and dynamic stability of an object (airplane, helicopter, glider, hang-glider etc.)?

The static stability takes into account only tendency to return to the equilibrium state, the dynamic stability takes into account objects's movement type.

There is no difference, the phenomenon is the same, just different names.

They differ in the importance - dynamic stability is more important.

The static stability concerns only balance on the ground, the dynamic stability - in-flight balance.

What is the "static instability" of an object (airplane, helicopter, glider, hang-glider etc.)?

A tendency (in a form of force or a moment) to continue moving in the direction of displacement following a disturbance.

Lack of any object reaction following a disturbance.

Static fluctuations around the object lateral axis.

Trim balance condition.

What is the "neutral static stability" of an object (airplane, helicopter, glider, hang-glider etc.)?

Lack of any object reacton following a disturbance.

A tendency (in a form of force or a moment) to return to equilibrium state following a disturbance.

Static fluctuations around the object lateral axis.

Trim balance condition.

What kind of profile doesn't create induced drag at zero angle of attack?

Double convex symmetrical.

Plano-convex.

Concave-convex.

Double convex asymmetrical.

For a constant accelerated motion, double increase of time at a constant acceleration causes:

A fourfold increase of the distance.

A double increase of the distance.

A double reduction of the distance.

A fourfold reduction of the distance.

For a constant accelerated motion, double increase of acceleration within a constant time causes:

A double increase in the distance.

A fourfold increase in the distance.

A double reduction in the distance.

A fourfold reduction in the distance.

For a rectangular planform wing it is true that:

The chord does not change along the wingspan.

The chord decreases along the wingspan.

The chord increases along the wingspan.

The chord at first increases and then decreases along the wingspan.

For the three wings with the same surface and the same wingspan, but with different planform (rectangular, tapered and elliptical), the Aspect Ratio is:

The same for all planforms.

Highest for an elliptical planform and the smallest for a rectangular.

Highest for the rectangular planform and the smallest for an elliptical.

Highest for an elliptical planform and the smallest for the tapered.

For an established descent the following equation is true:

Px=Q

Pz=Q

Q=Q

Pz=Px

PL080 - Principles of Flight PPL(A)

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