intro_to_aviation_block_4_20180401181938 Flashcards
(94 cards)
1
Q
how many thunderstorms are there at any given moment around the world
A
12 000
2
Q
what are the only clouds that produce thunderstorms
A
CB, Cumulonimbus
3
Q
what are the three requirements for thunderstorm formation
A
- unstable air (especially is unstable to high levels)2. Some from of lifting action to get the air moving upward3. air with high moisture content
4
Q
What are the three stages of a thunderstorm
A
- the cumulus stage2. The mature stage3. The Dissipating Stage
5
Q
Explain the cumulus stage
A
this stage is characterized by the formation of a cumulus cloud, that builds up to a towering cumulus, the cloud has mostly updrafts which support the water droplets within the cloud and no precipitation occurs
6
Q
explain the mature stage
A
is characterized by the build up into TCU/CB with very high tops. The updrafts within the cloud may attain 6000 feet/min. as the water droplets grow they start falling and drag air down with them, producing down drafts in the 2000ft/min range. this is the stage where most if not all the precipitation occurs. There is violent turbulence associated with the updrafts and downdrafts. Lighting, micro bursts, gust fronts, hail, tornadoes, and heavy precipitation are all associated with the mature stage
7
Q
The Dissipating stage
A
the onset of precipitation is the key to the dissipation of the thunderstorm cell. The precipitation cools down the lower part of the cloud, and breaks the updrafts that are the main source of its energy. The top of the cloud spreads out into anvil form.
8
Q
What are the two main types of thunderstorms
A
- air mass thunderstorms- frontal thunderstorms
9
Q
explain airmass thunderstorms
A
usually Form as a result of convection or orographic lift. Form individually or in clusters. Large clusters are collectively known as supercell
10
Q
Frontal thunderstorms
A
Are mostly associated with cold fronts but also occur with warm fronts. They usually form in a solid line several hundred miles long and in various stages of development. Warm front thunderstorms are often embedded in the main cloud deck and not as visible as cold front thunderstorms.
11
Q
What is an convection thunderstorm
A
scattered cloud, unequal heating of the ground,
12
Q
Advection Thunderstorms
A
Advection of cold air over a warm surface
13
Q
Orographic Thunderstorms,
A
air is lifted by sloping ground
14
Q
What are the three concepts related to air movement
A
- Gust fronts- Downburst- Downdrafts speed
15
Q
Explain Gust front as related to thunderstorm activity:
A
- strong downdrafts at mature stage- downdrafts spread out when reach ground- significant turbulence
16
Q
what are the two kinds of down bursts
A
Micro bursts and macro bursts
17
Q
Explain micro bursts
A
is a downburst of less then 2 miles in diameter and of short duration, typically less then 5 mins, can be wet or dry depending on precipitation
18
Q
Explain macro bursts
A
a large downburst with a diameter of 2 miles or more when it reaches the earths surface, damaging winds can last from 5 to 20 mins
19
Q
What does a downdraft in micro bursts do
A
vertical speed approaching 6000 feet/min as they reach the ground the spread out giving horizantal wind as much as 80 knots. Multiple micro bursts are common.
20
Q
What is virga
A
precipitation falling but not reaching the ground, associated with TCU and CB are ofter precursors of microbursts. The virgo evaporates below the cloud and as a result of the heat required for evaporation, the air in these regions become colder than its environment, sinking rapidly and accelerating downwards.
21
Q
Micro burst read over
A
Downward vertical winds can attain speeds as high as 6 000 feet/min (110 km/h). Outward horizontal wind guest speeds can reach up to 80 knots 140 kph at tree top levels The micro burst downdraft shaft can have a diameter of up to 6 000 feet 1.8 kmat ground level the vortex ring can have a horizontal extent of up to 2 1/2 mile (4 km) from the centre of the microburst.Microbursts do not have a long life span, lasting typically about 10 to 20 minutes, with the maximum wind intesities occurring about 5 mins after ground contact and lasting for about 2 mins.
22
Q
What are the nine areas of concern when flying near a thunderstore
A
- Turbulence2. hail3. lightning4. icing5. squall lines6. tornadoes7. low ceilings and visibilities8. heavy rain showers9. microbursts
23
Q
Turbulence
A
- strongest in a cumulonimbus cloud near the shear zone between the updrafts and down drafts (between 12000 and 20000 feet in the mature stage)- outside the cloud LLWS is presents below the cloud and is caused by downdrafts that race towards the ground Turbulence is also possible above the cloud (up to several thousands of metres) and outward up to 30 km. Often a roll cloud on the leading edge of the storm marks the position of the eddies in this shear zone, and is most prevalent with cold fronts and squall lines.
24
Q
Hail
A
- occurs in the mature stage of cells that have updrafts of more then usual intensity. - Around 10 000 to 15 000 feet- if the cloud is built up diagonally, hail that has been carried aloft in the updraft may be cast out into the clear air surrounding the cloud, from the sides or from the overhanging anvil cloud
25
Lightning
- he visible electric discharge produced by a thunderstorm. - It occurs in cloud (also called sheet lightning), cloud to cloud, cloud to ground and occasionally cloud to clear air- is always present or in the vicinity of cumulonimbus clouds- most present in CB clouds between 8 and -8 degrees celsius in the mature stage.- this is rarely a major hazard to aircraft but can cause the folowing: - Puncture the skin of the aircraft. - Damage communication and navigational equipment. - Temporally blind pilots. - Induce errors in magnetic compasses. - Disrupt low and medium radio frequencies. - More rarely, ignite fuel vapours.
26
Icing
- The most dangerous icing can occur in thunderstorms - clear and mixed icing is possible in all stages of development of thunderstorm clouds but severe clear icing is most likely in the upper half of thunderstorm cloud in the mature stage, especially when the temperatures are between 0 and -25 C- remember that strong up and downdrafts can rise or lower the freezing level within a thunderstorm cloud. It should also be remembered that a cluster of thunderstorm clounds could include several cells at various stages of development.
27
Squall Lines;
- a on frontal narrow band of highly active thunderstorms- can generally develop ahead a cold front in moist an unstable ai. It can for rapidly, reaching maximum intensity during the late afternoon r early evening hours. They can range from one to several hundred miles in length, and can be broken or in a continuous line.- A squall line can contain extremely sever thunderstorms (Torrential rains, large hail and tornadoes) and have all the other hazards generally associated with thunderstorms.
28
Tornadoes
- occur with isolated thunderstorms at times, but occur much more frequently with superecllular thunderstorms associated with cold fronts and squall lines- since vortex extends well up into the cloud a hidden vortex could be countered without seeing it- tornadoes can occur several kilometres outward from the main area of lightning and precipitation. cumulonimbus mamma cloud (round shaped under hanging below he cloud base or anvil) is often a signpost to tornadoes and violent turbulence
29
Low ceilings and visibilities:
- The visibility is generally near zero within a thunderstorm cloud. The ceiling and visibility aslo can greatly become reduces in the precipitation between he cloud base ad the ground. Heavy precipitation can saturate the ar rapidly causing stratus fractious and for to form rapidly reducing ceilings and visibility turning VFR approach into an IFR approach.- air craft would be restricted in these conditions, but the hazards become manifold when accompanies by other hazards such as turbulence, hail, lightning and low level wind shear, making precision instrument flying very difficult.
30
Heavy Rain Showers;
- the heaviest rain showers are associated with the mature stage of development with the onset of the first downdrafts- heavy rain showers associated with thunderstorms can cause contamination of the wing surface which results in early stall. If encountered during approach and landing, heavy rain can reduce visibility and cause refraction on the windscreen of the aircraft, procing an illusion that the runway threshold is lower than it actually is.- Water lying on the runway cause hydroplaning which destroys the braking action of the aircraft. Hydroplanning can also lead to loss of control during take-off
31
Micro Bursts;
- main effect is to cause sudden and dangerous low level wind shear, causing hazardous conditions for take-off and landing.
32
how cold can supercooled water droplets stay liquid to
-40C
33
What droplets freeze at warmer temperatures, bigger or smaller
larger
34
what kinda cloud makes the most frequent icing conditions
Stratocumulus
35
what cloud makes the heaviest icing potential
Cumulus, Towering cumulus and cumulonimbus
36
The amount of icing is directly related to...
the size of the water droplets
37
The size of the droplets is directly related to...
the vertical velocities within a cloud
38
do ice crystals adhere to aircraft
no
39
What is turbulance
Turbulence, an irregular motion of the air resulting from the formation of eddies or vertical currents in the air
40
what is the two categories of turbulence
1) Turbulence initiated by friction2) Turbulence initiated by Thermal (by heating) there are two types of forces creating thermal turbulence
41
What are the kinds of Turbulence initiated by friction
- Mechanical - Shear - frontal
42
What are the kinds of turbulence initiated by Thermal (by heating) there are two types of forces creating thermal turbulence
- Daytime convection - Cold air advection
43
What is mechanical turbulence
- the result between friction and ground- The following factors will effect the vertical extend (height) of this kind of turbulence - Stability of the air (more unstable means the higher the turbulence will extend) - Roughess of the ground (The rougher the surface, the greater the friction and the greater the degree of turbulence) - Strength of the wind (the stronger the wind the greater the friction and the greater the degree of turbulence
44
What is shear turbulence
the result of friction between opposing air currents
45
what is Frontal turbulence;
The result of friction between two opposing air masses near the frontal surface. This turbulence is most marked when the lifted warm air is moist and unstable. It will be extremely severe if thunderstorms develop Turbulence is more commonly associated with cold fronts, but may be pressent in a lesser degree in a warm front aswell
46
daytime convection thermal turbulence
- This is caused by vertical currents caused by unequal heating of the earths surface. The following factors will affect the strength and extend of convection currents; - The stability of the air - the degree of unequal heating
47
Cold air advection thermal turbulence
- when cold air moves over warmer water or land, heating from below creates unstable conditions that favour convection currents and turbulence. - The strong the contrast between the air and surface temperature, the more heating will be generated and the stronger the turbulence
48
Clear air turbulence
closely associated with the jet stream in a cloudless sky. can be severe enough to be a hazard to high performance aircraft. It occurs at high altitudes, 20 000 to 40 000 ft, and is most severe near or just below the jet stream core. CAT is also pronounced with sharply curved jets. some conditions associated with CAT;- no clouds- Strong jet stream- rapid change in wind speed over a short distance- rapid change of wind direction over a short distance
49
what does metar stand for
international meteorological code for a aviation routine weather report. Metars are normallyy taken and disseminated on the hour
50
What is a speci
a report taken at other times that reports sgnificant weather events for aviation not preciously reported
51
METAR CYWG 172000Z 30015G25KT 3/4SM R36/4000FT/D -SN BLSN BKN008 OVC040 M05/M08 A2992 REFZRA WS RWY36 RMK SF5NS3 SLP134name these
- Message type (Metar or Speci)- station indicator (4 letter ICAO identifier)- observation time ( DATE and time)- wind (first three digits in Degrees true, calm is denoted as 00000KT. The next two digits are speed, followed by if nessesry the later G and 2 digits to report the maximum gust speeds) - visibility (the visibility in statute miles)- RVR (The ten minuit average runway visual range is reported when prevailing visibility is 1 mile or less and or when the runway visual range is 6000 feet or less. The D indicates a downward trend, U means upward trend and N means no change)- present weather ( SEE WEATHER PHENOMENA CHART )- sky cover (the height and sky coverage amount)- temperature (the temperature rounded to the nearest degree, M means minus or negative)- dew point (follows the temperature with the same rules)- altimeter ( A indicates inches of mercury)- recent weather (things that have recently happened)- wind shear (WS will indicate which runway has wind shear affecting it)- remarks ( remarks of signicience to aviation, is preceded my RMK and will include in the following order, layer type, opacity in okras, general weather remarks, and see level pressure
52
Message type
Metar or Speci
53
station indicator
4 letter ICAO identifier
54
observation time
DATE and time
55
wind
first three digits in Degrees true, calm is denoted as 00000KT. The next two digits are speed, followed by if nessesry the later G and 2 digits to report the maximum gust speeds
56
visibility
the visibility in statute miles
57
RVR
The ten minuit average runway visual range is reported when prevailing visibility is 1 mile or less and or when the runway visual range is 6000 feet or less. The D indicates a downward trend, U means upward trend and N means no change
58
present weather
SEE WEATHER PHENOMENA CHART
59
Sky cover
the height and sky coverage amount
60
temperature
the temperature rounded to the nearest degree, M means minus or negative
61
dew point
follows the temperature with the same rules
62
altimeter
A indicates inches of mercury
63
recent weather
things that have recently happened
64
wind shear
WS will indicate which runway has wind shear affecting it
65
remarks
remarks of signicience to aviation, is preceded my RMK and will include in the following order, layer type, opacity in okras, general weather remarks, and see level pressure
66
For TAFS what is WS012/17010KT
means there is wind shear, details the hight, angle and knots
67
For TAFS what is TEMPO
means there is a temporary fluctuation during a period along with the date and time stated awsell
68
For TAFS what is PROB
means there is a probability fluctuation during a period along with the date and time stated awsell and the percentage
69
For TAFS what is FM
means a rapid change from a certain time onward
70
For TAFS what is BECMG
means a gradual change evolving between two times
71
For TAFS what is VBR
means no real direction of wind
72
UACN10 CYXU 11138YZUA /OV YVV 176025 /TM 1138 /FL100 /TPM20P /SK OVC090 /TA 01 /WV 270008 THIS IS A PIREP
.
73
For Pireps what does UA
menas normal pire
74
For Pireps what does UUA
means urgent pirep
75
For Pireps what does OV
location
76
For Pireps what does TM
time
77
For Pireps what does TP
aircraft type
78
For Pireps what does SK
Aircraft type
79
For Pireps what does TA
ambiant temperature
80
For Pireps what does WV
wind velocity
81
For Pireps what does TB
turbulance
82
For Pireps what does IC
icing
83
For Pireps what does RM
remarks
84
explain how location is written in a Pirep /OV YVV 176025
meaning 25 nautical miles 176 degrees of the navi aid at YVV
85
what are SIGMETs
- are weather advisory concerning weather significant to the safty of aircraft. They are issued by various weather centres across canada for their own areas of responsibility
86
When are SIGMENTs issued
- whenever at least one of the phenomena requiring a SIGMENT has been reporteted or is expected to occur within the next 4 hours. However a segment concerning volcanic ash cloud should be issued whenever pose, Up to 12 hours before the beginning of its period of coverage - the period of coverage of a sSIGMET will not exceed 4 hours
87
Example 1 of a sigment
WSCN32 CWEG 271513 SIGMET A1 VALID 271510/271910 CWEG- WTN 30 NM OF LINE 5221N 09701W/BERENS RIVER -/5037N 09702W/GIMLI. LN CB MOVG ENEWD 40 KTS. TOPS 350-400. OCNL VIS 1/4SM + TSRA GR. WIND GUSTS 35 KTS. SEV CLR ICG AND CVCTV TURB ASSOCTD. WKNG AFT 17Z
88
Example 2 of a sigment
CZQX SIGMET U3 VALID 291920/292320 CWUL- GANDER OCEANIC FIR. WTN 60 NM OF LN 4830N03830W -5300N04300W - 5430N04730W. SEVERE CLEAR AIR TURBULENCE FORECAST BETWEEN FL340 AND FL400. LINE MOVING EASTWARD 30 KNOTS. LITTLE CHANGED EXPECTED. END/GANDER OCEANIC/CMAC-E/RD/MDS.
89
what does Airmets stand for
- This is a short term weather advisory intended for aircraft in flight, to notify pilots of potentially hazardous weather conditions not described in the current GFA and not requiring a SIGMET
90
what is a airmets used for
- this is used as a tool to amend the GFA for the non-occurrence of a forcast condition and for the occurrence of a non forecast condition significant to aviation
91
how long is an airmet valid for
an airmen is valid until it is updated or canceled, or until the next regular GFA is issued, Whichever comes first
92
RO of FD chart
3000 6000 9000 12000 18000 YVR 2308 2310+03 2310-01 2212-07 2216-18 YYF 9900 2605+09 2408+01 2210-05 2019-16 YXC 2205+10 2211+03 2214-03 2118-14 YYC 1805+10 2009+03 2014-02 2019-13 YQL 2413+12 2320+06 2325-01 2132-13 YEA 1915+12 2023+07 2129+01 2142-12 YZP 2407 2308+01 2509-02 2712-07 2922-19
93
RO the codes for FD charts
dd = Direction true in 10 increments. ff = Speed in knots (9900 means direction variable, speed less than 5 knots). +/- = Sign of the temperature forecast at that altitude (none forecast for 3,000 feet). tt = forecast temperature in whole degrees Celsius. For wind speeds less then 5 knots we code it as 9900 for direction and speedFor over 100 knots we add 500 knots to direction (e.g. 7710 for a wind from 270° at 110 knots)
94
RO the codes for FD charts
dd = Direction true in 10 increments. ff = Speed in knots (9900 means direction variable, speed less than 5 knots). +/- = Sign of the temperature forecast at that altitude (none forecast for 3,000 feet). tt = forecast temperature in whole degrees Celsius. For wind speeds less then 5 knots we code it as 9900 for direction and speedFor over 100 knots we add 500 knots to direction (e.g. 7710 for a wind from 270° at 110 knots)
