Tidligere eksamen Flashcards
When considering the ICAO International Standard Atmosphere, which of the
following statements is correct?
1 - The temperature lapse rate is assumed to be uniform at 2°C per 1000 ft (1.98°C)
up to a height of 11000 ft.
2 - Sea level temperature is assumed to be 15°C.
3 - Sea level static pressure is assumed to be 1.225 kg/m3
4 - Sea level density is assumed to be 1013.25 hPa.
2 Only (note til nr1 den eneste forskel fra bogen og svar 1 er at der i bogen står at højden går fra MSL)
Dynamic pressure is equal to:
Half the density times the indicated airspeed squared.
What effect does landing at high altitude airports have on ground speed with comparable conditions relative to temperature, wind and aeroplane weight?
Higher than at low altitude.
If the angle of attack and other factors remain constant and airspeed is doubled, lift will be:
four times greater.
To avoid the wing tip vortices of a departing jet aeroplane during take-off, the pilot should:
climb above and stay upwind of the jet aeroplane’s flight path. (note: randhvivler falder med ca.500’/min og spreder sig til siden med ca. 5kt)
A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have:
A lower stall speed.
Which aircraft has the highest aspect ratio?
2
Air density is:
mass per unit volume. (kg/m3)
A moving mass of air possesses kinetic energy. An object placed in the path of
such a moving mass of air will be subject to what?
Static pressure and dynamic pressure.
The definition of lift is:
the aerodynamic force which acts at 90° to the relative airflow
The point on an aerofoil section through which lift acts is the:
centre of pressure.
Why does increasing speed also increase lift?
The increased speed of the air passing over an aerofoil’s upper surface
decreases the static pressure, thus creating a greater pressure differential
between the upper and lower surface.
A line drawn from the leading edge to the trailing edge of an aerofoil section and equidistant at all points from the upper and lower contours is called the:
mean camber line.
By changing the angle of attack of a wing, the pilot can control the aeroplane’s:
lift, airspeed, and drag.
What effect would a light crosswind have on the wing tip vortices generated by a large aeroplane that has just taken off?
The upwind vortex will tend to remain on the runway longer than the
downwind vortex.
Which flight conditions of a large jet aeroplane create the most severe flight hazard by generating wing tip vortices of the greatest strength?
Heavy, slow, gear and flaps up.
Determine the correct aspect ratio and wing area:
aircraft B has an aspect ratio of 13.7, and has a smaller wing area than aircraft A.
In theory, if the airspeed of an aeroplane is doubled while in level flight, parasite drag will become:
four times greater.
At a given True Airspeed, what effect will increased air density have on the lift and drag of an aircraft?
Lift and drag will increase.
Which aircraft has the lowest aspect ratio?
1.
What happens to total drag when accelerating from C_LMAX to maximum speed?
Decreases then increases.
At the airspeed represented by point B, in steady flight, the aeroplane will:
have its maximum L/D ratio
An aircraft has a L/D ratio of 15:1 at 50 kt in calm air. What would the L/D ratio be with a direct headwind of 25 kt?
15 : 1
If the same angle of attack is maintained in ground effect as when out of ground effect, lift will:
increase, and induced drag will decrease.
At a given Indicated Airspeed, what effect will an increase in air density have on lift and drag?
Lift and drag will remain the same.
Why do the lower layers contain the greater proportion of the whole mass of the atmosphere?
Because air is compressible.
On an aerofoil section, the force of lift acts perpendicular to, and the force of drag acts parallel to the:
flight path.
A static pressure vent must be positioned:
on a part of the structure where the airflow is undisturbed, in a surface
parallel to the airflow direction.
The angle between the chord line of an aerofoil section and the relative wind is
known as the angle of:
attack
Wing tip vortices created by large aircraft tend to:
sink below the aircraft generating the turbulence.
Lift on a wing is most properly defined as the:
force acting perpendicular to the relative wind.
To maintain altitude, what must be done as Indicated Airspeed (IAS) is reduced?
Increase angle of attack to maintain the correct lift force.
What flight condition should be expected when an aircraft leaves ground effect?
An increase in induced drag and a requirement for a higher angle of attack.
The angle between the chord line of the aerofoil section and the longitudinal axis of the aircraft is known as:
The angle of incidence.
Which statement is true, regarding the opposing forces acting on an aeroplane in steady-state level flight?
b. These forces are equal.
An aeroplane leaving ground effect will:
experience an increase in induced drag and require more thrust.
In theory, if the angle of attack and other factors remain constant and the airspeed is doubled, the lift produced at the higher speed will be:
four times greater than at the lower speed.
A symmetrical aerofoil section at CL
= 0 will produce?
Zero pitching moment.
When considering the properties of a laminar and turbulent boundary layer, which of the following statements is correct?
Friction drag higher in turbulent.
When compared to a laminar boundary layer:
a turbulent boundary layer has more kinetic energy.
