Aeroplanlære 40 spørgsmål

Question 1

Dynamic pressure is equal to:

Answer 1

Half the density times the true airspeed squared.
q = 1/2P * v^2

Question 1

When considering the ICAO international Standard Atmosphere, wich of the following statements is correct?

1) The temperature lapse rate is assumed to be uniform at 2C per 1000ft (1.98C) up to a height of 11.000ft.
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.

Answer 1

2 only

Explanation:
1) Er 36.000ft eller 11.000m
2) correct
3) Pressure is in hPa
4) Density is in kg/m3

Question 2

What effect does landing at high altitude airsports have on ground speed with comparable conditions relative to temperature, wind and aeroplane weight?

Answer 2

Higher than at low altitude

Question 3

If the angle of attack and other factors remain constant and the airspeed is doubled, lift will be:

Answer 3

Four times greater

Question 4

To avoid the wing tip vortices of a departing jet aeroplane during take-off, the pilot should…

Answer 4

Climb above and stay upwind of the jet aeroplane’s flight path

Bonus:
Rundvirvler falder med ca. 500’/min og spreder sig til siden med ca. 5 kt.

Question 5

A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have…

Answer 5

A lower stall speed

Bonus:
High aspect ratio = svævefly
–> de flyver meget langsomt, derfor vil det også kræve at de har en lav stall speed.

Question 6

Which aircraft has the highest aspect ratio?

1)
Span: 22.5 metres
chord: 4 metres

2)
Wing area: 90 square metres
Span: 45 metres

3)
Span: 30 metres
Chord: 3 metres

4)
Wing area: 90 square metres
Span: 40 metres

Answer 6

Number 2

Aspect Ratio = SPAN/CHORD
Wing area = B*A

B = span
A = wing area/ chord

Question 7

Air density is:

Answer 7

Mass per unit volume.

density is: kg/m3

Question 8

A moving mass of air possesses kinetic energy. An object placed in the patch of such a moving mass of air will be subject to which of the following?

a) dynamic pressure
b) static pressure
c) static pressure and dynamic pressure
d) dynamic pressure minus static pressure

Answer 8

c) static pressure and dynamic pressure

Question 9

The definition of lift is:

Answer 9

The aerodynamic force which acts at 90* to the relative airflow

Question 10

The point on an aerofoil section through which lift acts is the…

Answer 10

Centre of pressure

Question 11

Why does increasing speed also increase lift?

Answer 11

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.

Question 12

A line drawn from the leading edge to the trailing edge of an aerofoil section and equidistant (lige mellem bund og top) at all points from the upper and lower side is called the:

Answer 12

Mean camber line

Question 13

By changing the angle of attack of a wing, the pilot can control the aeroplane’s:

Answer 13

1) Lift
2) Airspeed
3) Drag

Question 14

What effect would a light crosswind have on the wing tip vortices generated by a large aeroplane that has just taken off?

Answer 14

The upwind vortex will tend to remain on the runway longer than the downwind vortex

Question 15

Which flight conditions of a large jet aeroplane create the most serve flight hazard by generating wing tip vortices of the greatest strength?

a) heavy, slow, gear and flaps up
b) heavy, fast, gear and flaps down
c) heavy, slow, gear and flaps down
d) weight, gear and flaps make no difference

Answer 15

a) Heavy, slow, gear and flaps up

Question 16

Determine the correct aspect ratio and wing area:

Aircraft A:
Wingspan 51m
Average wing chord: 4m

Aircraft B:
Wingspan: 48 m
Average wing chord: 3.5m

A) Aircraft B has an aspect ratio of 13.7, and has a smaller wing area than Aircraft A

B) Aircraft A has an aspect ratio of 12.75, and has a smaller wing area than Aircraft B

Answer 16

A) Aircraft B has an aspect ratio of 13.7, and has a smaller wing area than Aircraft A

Aspect Ratio = SPAN/CHORD
Wing area = B*A

B = span
A = wing area/ chord

Question 17

If the airspeed of an aeroplane is doubled while in flight, parasite drag will become:

Answer 17

Four times greater

Question 18

At a given True Airspeed, what effect will increased air density have on the lift and drag of an aircraft?

Answer 18

Lift and drag will increase

Question 19

Which aircraft has the lowest aspect ratio?

1)
Span: 22.5 metres
chord: 4 metres

2)
Wing area: 90 square metres
Span: 45 metres

3)
Span: 30 metres
Chord: 3 metres

4)
Wing area: 90 square metres
Span: 40 metres

Answer 19

Number 1

Aspect Ratio = SPAN/CHORD
Wing area = B*A

B = span
A = wing area/ chord

Question 20

What happens to total drag when accelerating from CLMAX to maximum speed

Answer 20

Decreases then increases

Question 21

If the same angle of attack is maintained in ground effect as when out of ground effect, lift will…

Answer 21

Increase, and induced drag will decrease

Question 22

At a given indicated airspeed, what effect will an increase in air density have on lift and drag

Answer 22

Lift and drag will remain the same

Question 23

Regarding the atmosphere. Why do the lower layers contain the greater proportion of the whole mass of the atmosphere

Answer 23

Because air is compressible

Question 24

On an aerofoil section, the force of lift acts perpendicular to, and the force of drag acts parallel to the….

Answer 24

Flight path

Question 25

A static vent must be positioned where?

Answer 25

On a part of the structure where the airflow is undisturbed, in a surface parallel to the airflow direction.

Question 26

The angle between the chord line of an aerofoil section and the relative wind is known as the angle of….

Answer 26

attack

Question 27

Wing tip vortices created by large aircraft tend to:

Answer 27

Sink below the aircraft generating the turbulence

Question 28

Lift on a wing is most properly defined as the…

Answer 28

Force acting perpendicular to the relative air

Question 29

To maintain altitude, what must be done as indicated airspeed is reduced?

Answer 29

Increase angle of attack to maintain correct lift force

Question 30

What flight condition should be expected when an aircraft leaves ground effect?

Answer 30

An increase in induced drag and a requirement for a higher angle of attack

Question 31

The angle between the chord line of the aerofoil section and the longitudinal axis of the aircraft is known as:

Answer 31

The angle of incidence

Question 32

Which statement is true, regarding the opposing forces acting on an aeroplane in steady-state level flight?

Answer 32

These forces are equal

Question 33

An aeroplane leaving ground effect will experience…

Answer 33

An increase in induced drag and require more thrust

Question 34

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…

Answer 34

Four times greater than at the lower speed.

Question 35

A symmetrical aerofoil section at CL = 0 will produce

Answer 35

No aerodynamic lift

Question 36

When considering the properties of a laminer and turbulent boundary layer, which of the following statements is correct?

a) Friction drag is the same

b) Friction drag higher in laminar

c) Friction drag higher in turbulent

d) Seperation point is most forward with a turbulent layer

Answer 36

C) Friction drag higher in turbulent

Question 37

When compared to laminar boundary layer..

a) A turbulent boundary layer has more kinetic energy

b) A turbulent boundary layer is thinner

c) Less skin friction is generated by a turbulent layer

d) A turbulent boundary layer is more likely to separate

Answer 37

a) A turbulent boundary layer has more kinetic energy