DLN Questions Flashcards
1
Q
(Unit 10) What clouds are classified as high clouds?
A
Cirrus (CI)
Cirrocumulus (CC)
Cirrostratus (CS)
2
Q
(Unit 10) What clouds are classified as middle clouds?
A
Altostratus (AS)
Altocumulus (AC)
Altocumulus Castellanus (ACC)
3
Q
(Unit 10) What clouds are classified as low clouds?
A
Stratus (ST) Stratocumulus (SC) Nimbostratus (NS) Stratus Fractus (SF) Cumulus Fractus (CF)
4
Q
(Unit 10) What clouds are classified as clouds of vertical development?
A
Cumulus (CU)
Cumulonimbus (CB)
Towering Cumulus (TCU)
5
Q
(Unit 10) What factors affect precipitation intensity?
A
Strength of the updraft within clouds
Cloud’s vertical thickness
Liquid water content of cloud
6
Q
(Unit 11) What flight problems occur in a warm front?
A
Extensive cloud, slow moving
Icing in cloud or precipitation is minimal when present
Low ceilings and visibility
Low level wind shear is possible
7
Q
(Unit 11) What flight problems occur in a cold front?
A
Strong convective clouds
Mechanical turbulence with gusty surface winds
Frontal wind shear
8
Q
(Unit 11) What factors determine the type and amount of weather at fronts?
A
Cold Front - Steeper slope giving a fast lift, but narrow lifting area
Warm Front - Shallow slope with a weak lift and very wide lift area
Trowals - Combination of warm and cold fronts
Quasi-stationary Front - Weakest lift
9
Q
(Unit 11) What is the stability of the warm air masses with layered clouds?
A
Stable air
10
Q
(Unit 11) What is the stability of the warm air masses with convective clouds?
A
Unstable air
11
Q
(Unit 11) What is the stability of the warm air masses with layered with embedded convective clouds?
A
Conditionally unstable air
12
Q
(Unit 12) What are the performance implications of icing accumulation?
A
Decrease in lift
Decrease in thrust
Increase in weight
Increase in drag
13
Q
(Unit 12) What are three meteorological factors affecting the formation of ice?
A
Liquid water content of air (LWC)
Temperature
Droplet size
14
Q
(Unit 12) What temperature is associated with “most icing”
A
0°C to -15°C
15
Q
(Unit 12) What temperature is associated with “most severe icing”
A
0°C to -10°C
16
Q
(Unit 12) What temperature is associated with “reduced icing”
A
-15°C to -40°C
17
Q
(Unit 12) What temperature is associated with “no icing”
A
-40°C
18
Q
(Unit 12) What temperature is associated with “severe icing in convective clouds”
A
-25°C
19
Q
(Unit 12) What is the easiest type of icing to remove?
A
Rime
20
Q
(Unit 12) What type of icing can spread over the whole wing?
A
Clear
21
Q
(Unit 12) What action must be taken in the case of moderate icing?
A
Keep anti/de-icing equipment running continuously
Divert
22
Q
(Unit 12) What type and intensity of icing is associated with FZDZ?
A
Light to moderate clear icing
23
Q
(Unit 12) Which cloud type is associated with “Rime Icing” and “Light, occasionally moderate intensity”
A
NS, ST, AS, AC, SC
24
Q
(Unit 12) Which cloud type is associated with “Mixed Icing” and “Light to moderate intensity”
A
NS, AS
25
(Unit 12) Which cloud type is associated with "Clear Icing" and "Severe intensity"
CB
26
(Unit 12) Which cloud type is associated with "Clear Icing" and "Moderate to Severe intensity"
ACC, TCU
27
(Unit 13) What are the three stages of development of a thunderstorm?
1. Cumulus Stage
2. Mature Stage
3. Dissipating Stage
28
(Unit 13) Which stage is the most severe stage?
Mature stage
29
(Unit 13) Which stage consists of only updrafts?
Cumulus stage
30
(Unit 13) What kind of thunderstorm is the weakest?
Warm frontal
31
(Unit 13) What type of thunderstorm is the most intense?
Squall
32
(Unit 13) What time of day are most thunderstorms most active?
Late afternoon
33
(Unit 13) T or F. Turbulence can only be found inside a thunderstorm.
False
34
(Unit 13) Where is the greatest turbulence inside a thunderstorm?
Between up and downdrafts
35
(Unit 13) What is the intensity of turbulence expected with most thunderstorms?
Severe
36
(Unit 13) What are the hazards associated with heavy rain during approach and landing?
Hydroplaning
Reduced visibility
Loss of lift
37
(Unit 13) What weather conditions are tornadoes associated with?
Updrafts
| Rain free area
38
(Unit 13) How many miles must thunderstorms be avoided by when using the radar (Radar Avoidance Rule)
5 miles below freezing level
10 miles between freezing level and 30,000'
20 miles above 30,000'
39
(Unit 14) The height of a constant pressure surface over a cold air mass will tend to be lower or higher than if over a warm air mass. What is the correct pressure?
Lower
40
(Unit 14) Strong horizontal temperature gradients tend to occur near what weather condition?
Fronts
41
(Unit 14) What is the minimum speed requirement for a jet?
60 kts
42
(Unit 14) Where is the axis of the jet stream located?
On the warm side of the surface front
43
(Unit 14) Where is the cirrus cloud located when it is associated with a west to east jet?
On the warm air side of the jet
44
(Unit 14) Where is the tropopause located on the jet
Above the jet
45
(Unit 14) Where are the strongest horizontal wind shears when your back is to the wind in a jet core?
To the left
46
(Unit 14) During which season are jet streams the strongest?
Winter
47
(Unit 14) What time of year are jet streams the highest
Summer
48
(Unit 14) What time of year are jet streams the furthest north?
Summer
49
(Unit 14) What are two non-frontal jets?
Arctic stratospheric
| Subtropical
50
(Unit 15) If you are entering an area of forecast CAT, what are your chances of encountering it?
>50%
51
(Unit 15) Since CAT usually occurs in relatively small areas it...
Can begin and end abruptly
52
(Unit 15) What causes CATs
Rapid changes in wind velocity (wind shear)
53
(Unit 15) What condition is required to make CAT
Vertical wind shear > 5 kts / 1000 ft
54
(Unit 16) What effect do mountain waves cause in aviation?
Fluctuating air speeds
55
(Unit 16) What are flight precautions to be used when flying in a mountain wave?
Approach the area at a 45° angle
56
(Unit 16) What are the various requirements for mountain wave formation?
Stable layer near mountain top
Wind speed at least 30 kts at crest and increasing with height
Mountain range (or line of hills)
Wind within 30° of perpendicular to mountain range - same direction all the way up
57
(Unit 16) Which cloud forms in the wave crest of a mountain wave?
Lenticular cloud
58
(Unit 17) What is the weather code for "Smoke"
FU
59
(Unit 17) What is the weather code for "Heavy Rain Showers"
+SHRA
60
(Unit 17) What is the weather code for "Light Ice Pellets"
-PL
61
(Unit 17) What is the weather code for "Snow and Heavy Blowing Snow"
SN +BLSN
62
(Unit 17) What is the weather code for "Heavy Rain and Mist"
+RA BR
63
(Unit 17) What is the weather code for "Heavy Thundershowers and Hail"
+TSRA GR
64
(Unit 17) What is the weather code for "Vicinity Showers"
VC SH
65
(Unit 17) What is the weather code for "Light Showers of Small Hail/Snow Pellets"
-SHGS
66
(Unit 17) What is the weather code for "Low Drifting Sand"
DRSA
67
(Unit 17) What is the weather code for "Light Freezing Rain and Mist"
-FRZA BR
68
(Unit 17) What is the weather code for "Light Snow and Ice Crystals"
-SN IC
69
(Unit 17) What is the weather code for "Light Rain and Snow"
-RASN
70
(Unit 1) What does a stable atmosphere mean?
It does not allow vertical overturning
71
(Unit 1) What are some of the characteristics of an unstable atmosphere to aircrew?
```
Turbulence
Gusty winds
Good visibility
Convective clouds
Thunderstorms
```
72
(Unit 1) What are some of the characteristics of a stable atmosphere to aircrew
Smooth flying
Layered clouds
Continuous precipitation
73
(Unit 1) What time of year is stable air most likely over the North Atlantic?
Spring and Summer
74
(Unit 1) How does icing affect an aircraft?
Decrease lift on take off
Reduced power
Restricts the performance of the control surfaces
75
(Unit 1) What is the boundary layer
The lowest layer where the atmosphere interacts with the earth's surface
76
(Unit 2) When a low pressure is deepening, in what way is the central pressure changing?
Decreasing
77
(Unit 2) What does the term PRESFR indicate?
A low is probably approaching rapidly
A high is probably leaving rapidly
The weather will likely get worse
The altimeter setting will be decreasing
78
(Unit 2) What is the definition of a "low pressure"?
Pressure is at a minimum
79
(Unit 2) What is the definition of a "Trof of low pressure"?
A line along which pressure is at a relative minimum
80
(Unit 2) What is the definition of a "Station Pressure"?
Measured pressure at the elevation of a particular location
81
(Unit 2) What is the definition of a "isobar"?
A line joining points of equal pressure
82
(Unit 2) How can you identify strong pressure gradients on a surface chart?
Isobars are close together
83
(Unit 3) Describe how the winds change from the surface to 3000ft
Wind veers 30° and doubles in strength
84
(Unit 3) What initially causes air to move?
Pressure gradient force
85
(Unit 3) What force deflects it to the right of its path?
Coriolis force
86
(Unit 3) Without friction air would move...
Parallel to isobars
87
(Unit 4) What changes to temperature and wind occur after a cold front passes?
Temperature decreases and wind veers
88
(Unit 4) Which air mass is the coldest?
cA
89
(Unit 4) Which air mass is the most unstable?
mT
90
(Unit 4) Which air mass likely holds the most moisture?
mT
91
(Unit 4) Which air mass covers most of Canada in the summer?
mP
92
(Unit 4) Which air mass forms over mid latitude oceans?
mP
93
(Unit 4) Which air mass forms over high latitude oceans?
mA
94
(Unit 4) Which air mass is cool, moist and unstable in the low levels?
mA
95
(Unit 4) What sign represents a quasi-stationary front?
Semi-circles and triangles
96
(Unit 4) What sign represents a cold front?
Triangles
97
(Unit 4) What sign represents a warm front?
Semi-circles
98
(Unit 5) Where is frontal shears most likely to occur?
In front of warm fronts
99
(Unit 5) You're landing into a 09010kts surface wind. At 1000' the wind is 09020kts. What type of performance shear will you encounter on descent?
Decreasing headwind
| Decreased performance shear
100
(Unit 5) What time of day would you expect the greatest wind shear in the boundary layer?
Night
101
(Unit 5) What is the effect "funnelling" has on wind?
Increases wind speed and wind becomes parallel to valley
102
(Unit 5) What degree of turbulence can be expected with the thunderstorm downdraft and gust front?
Moderate to severe
103
(Unit 5) What type of wind flows uphill during the day?
Anabatic winds
104
(Unit 5) What are three types of katabatic winds?
Night time wind
Glacier wind
Chinook wind
105
(Unit 5) Which of the katabatic winds is known for turbulence and strong wind shear?
Chinook wind
106
(Unit 5) What are the characteristics of turbulence?
Random spin motion of air
Abrupt up and down drafts
Strong wind shear
107
(Unit 5) What level of turbulence causes an A/C to be occasionally out of control?
Severe
108
(Unit 5) What are 3 requirements to make very rough mechanical turbulence?
Rougher terrain
Stronger wind
Unstable air
109
(Unit 5) What are the characteristics of wing tip vortices?
Strong rotational eddies
Trailer behind A/C wing tips
Spread Out
Sink and dissipate slowly
110
(Unit 6) What are the characteristics of a warm front?
Moves from SW to NE
Air behind a warm front is warmer and more moist than the air ahead of it
As the front moves through, cool, fair weather will follow
A warm front brings gentle rain or light snow, followed by warmer, milder weather
Precipitation will be gradual and being ahead of the surface front in the form of drizzle or light snow and covering a large area
111
(Unit 6) What are the characteristics of a cold front?
Transition zone where a cold air mass is replacing a warmer air mass
Moves SE to NW
Heavy showers or thunderstorms in a narrow line along the cold front usually with gaps between them
Turbulence is common near cold fronts especially in and near the convective clouds that produce the showers and thunderstorms
112
(Unit 6) What term has the following description "Heavy showers or thunderstorms in a narrow line along the cold front usually with gaps between them"?
Cold Front
113
(Unit 6) What term has the following description "Precipitation will be gradual and begins ahead of the surface front in the form of drizzle or light snow and covers a large area
Warm front
114
(Unit 6) What term has the following description "Typically stormy weather and colder air at the surface and heavy precipitation"?
TROWAL
115
(Unit 6) What are the characteristics of Radiation Fog?
Forms in the early morning and dissipates by noon
116
(Unit 6) What are the characteristics of Frontal Fog?
Develops in the precipitation ahead of a warm front and persists until the front moves away. Upslope flow makes the situation worse
117
(Unit 6) What are the characteristics of Advection Fog?
Develops as warm air moves over cold water
118
(Unit 7) What is the definition of Convection?
Surface layer of air heated by conduction becomes buoyant and rises up through the atmosphere as a convective current that carries surface heat upward into the atmosphere
119
(Unit 7) What is the definition of Turbulent Mixing?
Wind causes turbulent air motion that mixes the surface layer of air that has been heated by conduction with the heated air aloft; spreading the heat upwards
120
(Unit 7) What is the definition of Latent Heat
Water vapour evaporated into the atmosphere from the earth's surface is frequently carried aloft. If it should condense, its latent heat is released. This heat, which originated near the earth's surface in the evaporation process, is there by distributed in higher levels of the atmosphere by condensation.
121
(Unit 7) What is the definition of Advection Warming?
Air being carried from a cold portion of the earth's surface to a warmer portion by wind will have its lowest levels heated by conduction and the heat will be distributed upward by convection and turbulent mixing
122
(Unit 7) What is the definition of Compression?
Occasions when large sections of the earth's atmosphere subside. This would occur in the instance of air flowing down the side of a mountain range. As the air descends, it comes under increased atmospheric pressure and is compressed. This compression heats the subsiding air.
123
(Unit 7) What are five mechanisms that cause expansion cooling and are responsible for the different clouds that form?
```
Mechanical turbulence
Low level convergence
Orographic lift
Frontal lift
Convection
```
124
(Unit 7) As air rises it expand and cools. What is the definition of Dry Adiabatic Lapse Rate (DALR)?
Air will cool/warm at 3°/1000' of ascent or descent
125
(Unit 7) As air rises it expand and cools. What is the definition of Saturated Adiabatic Lapse Rate (SALR)?
Air will cool/warm at 1.5°C/1000' of ascent of descent
126
(Unit 8) What are the characteristics of an Unstable Environment?
Turbulent
Gusty Winds
Convective Clouds
Good Visibilities except in showers
127
(Unit 8) What are the characteristics of a Stable Environment
Steady Winds
Layered clouds when clouds are present
Poor visibilities when weather is present
Little turbulence
128
(Unit 8) What increases stability by cooling lower levels?
At night due to radiation cooling
When warm air moves over cool water - Advection Cooling
Over the East Coast in Labrador during the spring and summer causing fog
129
(Unit 8) True or False? Air becomes more stable due to daytime heating.
False
130
(Unit 8) True or False? Warm air rising up the warm frontal surface increases stability below.
True
131
(Unit 8) True or False? Cold air flowing over a warm body of water clears the skies.
False
132
(Unit 8) True or False? The air near the earth's surface becomes unstable at night.
False
133
(Unit 8) Air with a temp of 26°C and dew point of 23°C moves poleward over a large water surface with a temp of 12°C. What is true about this statement?
The Lapse Rate (ELR) becomes an inversion and fog forms
