Chapter 7.2 - An Introduction to Meteorology Flashcards
1
Q
Name three weather phenomena that have more detrimental effect on an Aircraft at relatively low level?
A
- Poor Visibility/ Low Cloud Ceilings.
- Thunderstorms.
- Turbulence.
- Windshear.
- Thermals and Dust Devils.
2
Q
Poor Visibility is associated with what (3)?
A
- Low Cloud Ceilings.
- Fog/Duststorms/Haze.
- Precipitation.
3
Q
Name four examples of Precipitation?
A
- Heavy Rain.
- Drizzle.
- Snow.
- Sleet.
4
Q
True or False. Clouds are formed when the moist air is cooled to below a temperature where it cannot hold any more water vapour?
A
True.
5
Q
When the air is unstable, what type of clouds are formed?
A
Cumuliform Clouds.
6
Q
When the air is stable, what type of clouds are formed?
A
Stratiform Clouds.
7
Q
Clouds which are bunched or heaped together, have a significant vertical development and are generally separated from each other are called what?
A
Cumuliform.
8
Q
Clouds which are formed into sheets or layer, which may cover large areas of the sky are called what?
A
Stratiform.
9
Q
Low Cloud is classified as cloud with a base from the earth’s surface up to about ‘x’ feet. What is ‘x’?
A
8500ft.
10
Q
A stable atmosphere is normally associated with what kind of pressure area?
A
High.
11
Q
High Pressure Area is also known as?
A
Anticyclone.
12
Q
Stratus usually has a very low base. What two factors can reduce the visibility in VFR flight?
A
- Low Ceiling.
- Drizzle.
13
Q
Fog can reduce horizontal visibility to ‘x’ metres or less. What is ‘x’?
A
1000m.
14
Q
In Mist, the horizontal visibility generally remains (above/equal/below) 1000 metres?
A
Above.
15
Q
True or False. Stratocumulus can also have a low base, or obscure high terrain?
A
True.
16
Q
Name two types of Low Cumuliform Clouds and their abbreviations as used in weather forecasts?
A
- Cumulonimbus (CB).
- Cumulus (CU).
17
Q
An unstable atmosphere is normally associated with what kind of pressure area?
A
Low.
18
Q
Low Pressure Area is also known as?
A
Depression.
19
Q
What is the name given to lines joining places of equal pressure on a weather map called?
A
Isobars.
20
Q
True or False. The closer together the Isobars, the lighter the wind?
A
False. The stronger the wind.
21
Q
In the Southern Hemisphere, the wind blows anticlockwise around what kind of pressure area?
A
High Pressure Area (anticyclone).
22
Q
In the Southern Hemisphere, the wind blows clockwise around what kind of pressure area?
A
Low Pressure Area (depression).
23
Q
What does NS stand for?
A
Nimbostratus.
24
Q
Temperature Inversion is a condition in the atmosphere where the temperature (increases/decreases) with height?
A
Increases.
25
Severe dust storms may reduce visibility to below ‘x’ metres?
200m.
26
Name seven meteorological hazards that Thunderstorms produce?
- Turbulence.
- Hail.
- Icing.
- Lightening.
- Gusts.
- Low Ceiling.
- Poor Visibility.
27
What should Pilot if they see a Thunderstorm ahead?
Avoid at all costs.
28
What is the worst hazard of a Thunderstorm?
Turbulence.
29
True or False. Turbulence from a Thunderstorm is not enough to cause severe structural damage?
False. Turbulence from a Thunderstorm has the potential to cause structural damage.
30
True or False. Hailstones from a Thunderstorm can be extremely large and damage an Aircraft?
True.
31
What can ice deposits on an airframe lead to what degrading performances on an Aircraft (3)?
- Reduction in Lift.
- Increase in Drag.
- Can cause the Aircraft to stall at higher speeds.
32
Name five possible signs indicating Turbulence in the Air?
- Thunderstorms.
- Towering Cumulus Clouds.
- Strong Winds (in the excess of 25kts).
- Virga.
- Cold Fronts.
33
Define Virga?
Precipitation which evaporates before reaching the ground.
34
What does Virga suggest?
Strong downdrafts.
35
What should Pilots do if they detected presences of Virga?
Avoid flying underneath these clouds.
36
What is a ‘front’ in weather terms?
Two air masses of differing temperatures (warm and cool).
37
Define Cold Front?
Cooler air displaces warm air.
38
How is a Cold Front displayed on a weather map?
A line marked with barbs in the direction of movement.
39
What does FBL stand for in relation with Turbulence?
Feeble/light.
40
What does MOD stand for in relation with Turbulence?
Moderate.
41
What does SEV stand for in relation with Turbulence?
Severe.
42
Apart from Thunderstorms, can Turbulence itself cause Structural Damage?
Rarely.
43
The critical factor with Turbulence is the Aircraft’s speed. What can happen at high and low Airspeeds (2)?
- High = Overstress the structure.
| - Low = Gust-induced roll.
44
True or False. A compromise speed must be used to penetrate turbulence if flight through turbulence cannot be avoid?
True.
45
For Light Training Aircraft, the turbulence penetration speed is between which percentages above the clean stall speed?
40% to 60%.
46
Where can the turbulence penetration speed be found in?
Pilot’s Operating Handbook.
47
Unexpected Turbulence: How should the speed be changed?
Slowed down to its turbulence penetration speed.
48
Unexpected Turbulence: What should be checked in the cockpit?
Any loose articles.
49
Unexpected Turbulence: What position should the flaps be at?
Up position.
50
Unexpected Turbulence: What changes should be made with the Attitude?
Small changes.
51
Unexpected Turbulence: Should a Pilot re-trim the Aircraft?
No.
52
Unexpected Turbulence: What should be avoided if turning the Aircraft?
Large bank angles.
53
Low level Windshear is the term used to describe what? From the surface to about ‘x’ feet AGL (2)?
- Sudden change in wind speed and/or direction.
| - 2000ft AGL.
54
When Windshear involves only a change in speed with changing height, this is called what?
Wind Gradient.
55
Name two signs of that may indicate the presence of Windshear?
- Strong Winds.
| - Forecast Gusts.
56
What are Thermals?
A column of hot rising air.
57
Which type of flight will Pilots use Thermals?
Gliders as it allows the glider to gain height.
58
True or False. Dust Devils are smaller and less violent form of Thermals?
False. More violent form of Thermals.
59
Dust Devils move at speeds varying between how many knots? They normally only rise to height of less than ‘x’ feet (2)?
- 5 to 25 knots.
| - 100 feet.
60
The forecast signs of Thermals and Dust Devils are in which conditions?
Hot and Dry.
61
What are Weather Forecasts?
Estimates of what meteorological conditions are likely to be at some future time.
62
What does ARFOR stand for?
Area Forecasts.
63
What does TAF stand for?
Aerodrome Forecasts.
64
In TAF, which level is used to describe clouds (AMSL/AAL)?
AAL.
65
In ARFOR, which level is used to describe clouds (AMSL/AAL)?
AMSL.
66
When describing the amount of cloud, what does SKC mean and how many OKTAs (2)?
- SKC = Clear Sky.
| - 0 OKTA.
67
When describing the amount of cloud, what does FEW mean and how many OKTAs (2)?
- FEW = Few Clouds.
| - 1-2 OKTA.
68
When describing the amount of cloud, what does SCT mean and how many OKTAs (2)?
- SCT = Scattered Clouds.
| - 3-4 OKTA.
69
When describing the amount of cloud, what does BKN mean and how many OKTAs (2)?
- BKN = Broken Clouds.
| - 5-7 OKTA.
70
When describing the amount of cloud, what does OVC mean and how many OKTAs (2)?
- OVC = Overcast.
| - 8 OKTA.
71
When describing the amount of Cumulonimbus cloud, what does ISOL mean?
Isolated.
72
When describing the amount of Cumulonimbus cloud, what does OCNL mean?
Occasional.
73
When describing the amount of Cumulonimbus cloud, what does FREQ mean?
Frequent.
74
A TAF report will use TEMPO to indicate changes in prevailing conditions. What does TEMPO mean and how long is it expected to last for (2)?
- Temporary.
| - 30 to 60 minutes.
75
A TAF report will use INTER to indicate changes in prevailing conditions. What does INTER mean and how long is it expected to last for (2)?
- Intermittent.
| - Last for less than 30 minutes.
76
What abbreviations are used in conditions expected to be of a more lasting nature than TEMPO and INTER (2)?
- FM (from).
| - BECMG (becoming).
77
What format is used to describe FM in a weather report?
FM DDHHMM.
78
What format is used to describe BECMG in a weather report?
BECMG DDHH/DDHH.
79
How would ‘From 1715 on 24th’ be seen on a weather report?
FM 241715.
80
How would ‘Becoming 2325 on 17th and 0345 18th’ be seen on a weather report?
BECMG 1723/1803.
81
In TAF, what is shown when visibility is above 10km?
9999.
82
What does the first three digits represent when describing Wind Velocity?
Wind direction relative to True North.
83
What does the next two digits represent when describing Wind Velocity?
Windspeed in knots.
84
What does 18010G25KT mean?
Wind Velocity is forecasted at 180°T at 10 knots with Gusts to 25 knots.
85
In TAF, when the wind is of variable direction and has a speed of less than 5 knots, what is the abbreviation shown as?
VRB.
86
If wind is calm, it is encoded as what?
00000KT.
87
What does SH mean in MET terms?
Showers.
88
What does TS mean in MET terms?
Thunderstorms.
89
What does DZ mean in MET terms?
Drizzle.
90
What does RA mean in MET terms?
Rain.
91
What does SN mean in MET terms?
Snow.
92
What does PL mean in MET terms?
Ice Pellets.
93
What does GR mean in MET terms?
Hail.
94
What does BR mean in MET terms?
Mist.
95
What does FG mean in MET terms?
Fog.
96
What does FU mean in MET terms?
Smoke.
97
What does HZ mean in MET terms?
Haze.
98
What does PO mean in MET terms?
Dust Devils.
99
What does DS mean in MET terms?
Duststorms.
100
What does UP mean in MET terms?
Unknown Precipitation.
101
In TAF, what does the term WX NIL mean?
No weather.
102
In TAF, what does the term NOSIG WX mean?
No significant weather.
103
In TAF, what does the term SKC mean?
No cloud.
104
In ARFORs, what does FBL mean?
Light Turbulence.
105
What does CAVOK mean?
Ceiling and Visibility are OK.
106
In ARFORs, what information is given under Overview?
Brief description of MET.
107
In ARFORs, what information is given under Winds (4)?
- Wind Direction in relation to True North.
- Wind Speed in Knots.
- Altitude of Wind in AMSL.
- Temperature.
108
In ARFORs, what does PS and MS stand for when describing temperature?
- PS = Plus Celsius.
| - MS = Minus Celsius.
109
In ARFORs, what information is given under Weather?
MET abbreviation of the current weather.
110
True or False. In ARFORs, FG assumes a visibility of 1000m or less?
True.
111
In ARFORs, what is the measurement under Visibility (2)?
- Metres for less than 5000m.
| - Kilometres for more than 5000m.
112
In ARFORs, what is the measurement under Freezing Level?
In feet AMSL.
113
In ARFORs, what are the three abbreviations given under Icing and Turbulence?
- FBL (light).
- MOD (moderate).
- SEV (severe).
114
How many times are ARFORs issued daily?
Three times a day.
115
How long are ARFORs valid for?
12 hours.
116
What would AREA FORECAST 202300 TO 211100 indicate?
Period of validity is from 2300h on 20th to 1100h on 21st.
117
What would WIND 2000 050/20 and 14000 040/25 MS07 indicate?
- At 2000ft, Wind is blowing from 050°T at 20kts.
| - At 14000ft, Wind is blowing from 040°T at 25kts with minus 7°C.
118
What would the below indicate under CLOUD?
ISOL EMBD CB 3000/40000
BKN ST 1000/4000 in RA/TS
OVC NS 2000/280000 LYR
- Isolated embedded Cumulonimbus, base 3000ft AMSL to tops at 40000ft.
- Broken Stratus, base 1000ft AMSL to tops 4000ft in Rain and Thunderstorms.
- Overcast Nimbostratus, base 2000ft in layers to 28000ft.
119
What would WEATHER TS RA indicate?
Weather is Thunderstorms and Rain.
120
What would VISIBILITY 20KM DTRT 5000M RA 2000M TS indicate?
Visibility of 20km deteriorating to 5000m in rain and 2000m in Thunderstorms.
121
What would TURBULENCE SEV IN/NEAR CB indicate?
Turbulence is severe in or near Cumulonimbus.
122
A TAF is a statement of expected meteorological conditions for a specified period in the Airspace within the radius of how many NM from the centre of the aerodrome?
5NM.
123
What does TAF AMD mean?
Original TAF has been amended.
124
What does TAF COR mean?
Correction in previous TAF.
125
What does TAF PROV mean?
A TAF likely to be deficient in accuracy.
126
What does NIL mean?
No current TAF for this location.
127
What does CNL mean?
Cancels a current TAG at this location.
128
What is the period of validity format in a TAF?
DDHH/DDHH
129
What does ‘0100/0206’ indicate?
TAF report is valid from 0000 on 1st to 0600 on 2nd (30 hours).
130
How is Visibility formatted in a TAF and what’s the measurement used (2)?
- Four-figure group.
| - Metres.
131
What does RMK stand for in TAF reports?
Remarks.
132
Name three codes used in TAF reports to illustrate the level of Turbulence?
- MOD TURB.
- MOD/SEVE TURB.
- SEV TURB.
133
When significant low-level Turbulence is present in a TAF report, how is the height below which the Turbulence is forecast written as?
BLW ….. FT.
134
What letters are used to describe temperatures and QNH in a TAF report (2)?
- T.
| - Q.
135
True or False. Aerodrome weather reports are observations of actual meteorological conditions existing at a particular time at an aerodrome?
True.
136
What does AWS stand for?
Automatic Weather Station.
137
What is the abbreviation used for routine aerodrome weather reports?
METARs.
138
What is the abbreviation used for special aerodrome weather reports?
SPECIs.
139
What are the two factors VFR Pilots should look at for in Forecasts and Reports?
- Cloud Base.
| - Cloud Cover.
140
The higher the cloud base, the less or more important the cloud cover?
Less
141
The lower the cloud base, the less or more important the cloud cover?
More.
142
Is the following examples safe for VFR flight? The cloud base 1500ft AGL or less and cloud is cover is greater than SCT/4 OCKTAs?
VFR is not safely possible.
143
Is the following examples safe for VFR flight? The cloud base 1500ft to 2500ft AGL and cloud is cover is greater than SCT/4 OCKTAs?
VFR only marginally possible.
144
Is the following examples safe for VFR flight? The cloud base 1500ft to 2500ft AGL and cloud is cover is less than BKN/5 OCKTAs?
VFR possible with care.
145
Is the following examples safe for VFR flight? The cloud base 2500ft AGL or higher and cloud is cover is less than BKN/4 OCKTAs?
VFR is possible.
146
As well as clouds, name four other factors VFR Pilots should look out for?
- Visibility.
- Wind.
- Weather.
- Turbulence.
147
At what speed of wind should VFR not be possible for?
25 knots.
148
What kind of weather should VFR Pilots look out for in Forecasts and Reports?
Anything which may reduce visibility.
149
What does ATIS stand for?
Automatic Terminal Information Service.
150
What is the main purpose of ATIS?
To provide Pilots with actual operational and weather information relating to Takeoff and Landing.
151
What does an ATIS broadcast start with (2)?
- Aerodrome name.
| - Sequential code letter for the conditions at that particular time.
152
Runway and Wind directions in an ATIS broadcast are given in which type of degrees?
Magnetic.
