問題一覧
1
gases proportions in the atmosphere are in the following (by volume
Nitrogen 78% Oxygen 21
2
Weather systems exists in the
troposphere only
3
The tropopause occurs where
the temperature ceases to decrease as altitude increases
4
Ozone is mainly found in
stratosphere and troposphere
5
Temperature is a measure of
the internal kinetic energy of a substance As temperature increases, the molecular movement of the substance Increases
6
Lapse rate is referred to
the decrease of temperature with an increase of height
7
Lapse rate comparable value of
1.98°c/1000ft often rounded 2°c/1000 ft
8
In aviation the actual atmospheric temperature is very often expressed
as the outside air temperature (OAT
9
At high temperature airfield a longer take-off run is
required for a fixed throttle setting
10
Standard sea level temperature
is 15 degrees Celsius
11
Isobars used on a weather map are
lines of equal pressure
12
pressure is caused by
the mass air acting under the force of gravity on a given area
13
It should be noted that at about 18,000 ft. the pressure
is half the sea level value
14
pressure altitude
The height that a given pressure occurs
15
Absolute pressure
= Gauge pressure + Atmospheric pressure
16
A gauge pressure of 25,3 PSI (in the International Standard Atmosphere) what is absolute pressure
40.0 PSI
17
Density is
expressed in grams, or kilograms per cubic meters for metric or SI units
18
reduction in air density
reduces the wing’s lift
19
Air at low altitude
has the greater density
20
It is possible to change the static pressure of air by forcing the
air through a venture tube. As air flows through a narrowing port, its static pressure will decrease
21
The airspeed indicator uses pitot pressure inside the capsule, and static pressure outside the capsule and
thus measures dynamic pressure
22
dew point
is the temperature to which humid air must be cooled at a constant pressure to become saturated
23
As an incompressible fluid flows through a duct of varying cross sectional area, the mass flow rate remains constant. this is defined as
the principle of continuity
24
Ground speed can be determined
by the vector sum of the aircraft's true airspeed and the current wind speed and direction.
25
The resultant airflow that affects the wing is made
by the relative horizontal and vertical airflow components.
26
The chord line of a wing is a line that
runs from the centre of the leading edge of the wing to the trailing edge.
27
Angle of attack
is the angle between oncoming air (or relative airflow) and the chord line of the wing.
28
An increase in the angle of attack will cause
the centre of pressure to move forward
29
when trailing edge flaps are deployed, the camber and the angle of attack are both
increased
30
An increase in aircraft weight
will increase the stall speed
31
In straight and level flight
lift = weight, and thrust = drag
32
Rate of climb is dependent upon
excess power
33
The glide ratio is the same as the
lift/drag ratio
34
The best gliding angle is achieved by using the angle of attack that gives
the best L/D ratio
35
Compared to straight and level flight, when an aeroplane is turning
stall speed increases and load factor increases
36
A minimum radius turn is easier achieved
at low altitude
37
During a turn, for any given speed
the radius of turn will depend upon the angle of bank
38
An increase in altitude will cause the rate of turn
to decrease
39
To achieve a maximum rate turn, it can be shown that
Wing loading must be as low as possible
40
Flaps at landing position
decrease landing speed
41
The load factor of a given aircraft in a given condition of flight is defined as
the lift divided by the weight
42
During a turn
insufficient rudder causes slip
43
Fowler flap
increases the area of the wing
44
A winglet
reduces drag and increases thrust
45
Winglets
reduce tip vortices, increasing the effective aspect ratio
46
Ground effect results
in increased lift and reduced drag
47
Ground effect
interferes’ with the formation of the tip vortices.
48
In the case of an aircraft making a turn, the force causing centripetal acceleration
is the horizontal component of the lift acting on the aircraft
49
A standard rate turn is defined as a 3° per second turn, which completes a 360° turn in 2 minutes
This is known as a 2-minute turn or rate one (180°/min)
50
The power provided by jet and piston engines alike decrease with altitude
due mainly to decreasing air density
51
When an aeroplane is in an unpowered descent, a component of the weight
acts forwards along the flight path, and provides the ‘thrust’ to drive the aeroplane forwards against the drag
52
In any manoeuvre, the stalling speed is
proportional to the square root of the load factor
53
When a turn is executed without any skid or slip, it
is called a coordinated turn
54
Movement about the normal axis is called
yawing
55
Primary controls
ailerons, elevator (or, in some installations, stabilator) rudder
56
If aircraft moves in roll the axis it is moving about
is Longitudinal
57
Stability of an aircraft
is the tendency of the aircraft to return to its original trimmed position after having been displaced
58
incorporation of an artificial stability mechanism, using sensors, computers and inputs to the aircraft’s trim or primary control systems
this is known as active stability
59
If, after disturbance, an aeroplane initially returns to its equilibrium state.
It has static stability and may be dynamically stable
60
Moving the centre of gravity forward, away from the centre of pressure will
increase longitudinal stability
61
If horizontal stabilizer is re-positioned to a location further from the aircraft’s centre of gravity
it will Increase the aircraft’s longitudinal stability.
62
Blanketing effect will increase
lateral stability
63
When an aeroplane with swept wings sideslips, the leading wing has
greater span than the trailing wing
64
Porpoising
is a longitudinal instability
65
Dihedral
is an outward and upward inclination of the wings to increases lateral stability.
66
High winged aircraft usually have less dihedral than low winged aircraft
because the pendulum effect of a high winged aircraft provides a considerable amount of lateral stability
67
Anhedral
is an outwards and downward inclination of the wings to reduce stability.
68
Blanketing effect will increase
lateral stability
69
If the aeroplane is loaded with the centre of gravity too far aft
the aeroplane may assume a nose up rather than a nose down attitude
70
Longitudinal stability is pitch stability, or stability around
the lateral axis of the aeroplane
71
Positive longitudinal dynamic stability is provided solely
by the horizontal stabiliser
72
The aero foil produces zero lift at a certain
negative angle of attack
73
Drag acts in a direction parallel with the relative airflow, and is therefore
always perpendicular to lift (where generated
74
the aspect ratio of a wing is the ratio of
its span to its aerodynamic chord
75
A wing of area 12 m² and span of 12m has an aspect ratio of
12
76
Wing loading is calculated by
weight divided by gross wing area
77
Longitudinal dihedral angle is defined asLongitudinal dihedral angle is defined as
the difference the angle of incidence of the mainplane and tailplane
78
Wing tip vortices on conventional aeroplanes create
additional drag and reduce lift
79
Skin friction drag increases with
increasing turbulent boundary layer
80
Friction drag can be reduced by
delaying the point at which laminar flow becomes turbulent
81
Induced drag
is greater at low aspect ratio wing
82
Profile drag
increases with the square of the IAS
83
If the weight of an aircraft is increased
minimum drag speed will increase
84
Vortex generators
move the transition point forwards towards the leading edge of the wing
85
Dogtooth extensions, leading edge cuffs and vortillons are all designed to
prevent wing tip stalling at low speed
86
At small angle of attack the Cp is located between
40to 50% of the chord
87
If an aircraft with swept wings begins to tip-stall
it will pitch up
88
Accretion of ice on
a wing will increase stall speed
89
The normal axis of an aircraft passes
through the center of gravity
90
Directional stability is stability about
the normal axis