AFT MET Flashcards
The troposphere:
A. Is a section of the atmosphere above the tropopause where there is little or no change in temperature with height
B. Is 8-18km above the earths surface where a marked change in temperature lapse rate is apparent
C. Contains most of the water vapour of the atmosphere and the temperature generally decreases with height
D. Is the boundary between the tropopause and stratopause
Contains most of the water vapour of the atmosphere and the temperature generally decreases with height
With increasing altitude in the stratosphere, temperature:
A. Increases
B. Remains the same
C. Decreases
D. Is isothermal
Increases
*In the lower parts of the stratosphere, temp is constant which is called isothermal and then increases with altitude
The tropopause is:
A. A region in the upper stratosphere where the temperature decreases with height
B. A region 8-18km above the earths surface at which a marked change in temperature lapse rate is apparent
C. That portion of the earths atmosphere in which weather occurs
D. A level within 3000ft of the ground at which a marked change of lapse rate is indicated on cold clear mornings
A region 8-18km above the earths surface at which a marked change in temperature lapse rate is apparent
In ISA, from MSL to the tropopause, the decrease of temperature with height is approximately:
A. 1C/1000ft
B. 1.5C/1000ft
C. 2C/1000ft
D. 3C/1000ft
2C/1000ft
*Up to 36,090ft where the tropopause starts
In ISA, the tropopause is found at:
A. The equator
B. 0HPA pressure
C. 36,090ft
D. 8km above the poles
36,090ft
One of the major differences between the troposphere and stratosphere is that the stratosphere:
A. always has a higher temperature and humidity than the troposphere
B. has almost no clouds
C. always has a lower temperature and humidity than the tropopause
D. always has a greater wind velocity than the troposphere
has almost no clouds
*Stratosphere has the isothermal layer and then temp increases with height, has almost no clouds
From the earths surface, the vertical structure:
A. tropopause, stratosphere, troposphere
B. stratosphere, troposphere, tropopause
C. troposphere, stratosphere, tropopause
D. troposphere, tropopause, stratosphere
Troposphere, tropopause, stratosphere
*stratopause, mesosphere, mesopause,
The lapse rate in the stratosphere is due to:
A. nearness of the sun
B. lack of air
C. radiation from the earth
D. presence of heat absorbing ozone
presence of heat absorbing ozone
*Ozone absorbs the UV coming from the sun
The section of the atmosphere where most weather occurs is:
A. Troposphere
B. Stratosphere
C. Stratopause
D. Friction layer
Troposphere
*Friction layer is surface-3000ft
The temperature at the base of the stratosphere is lowest over:
A. equator
B. 30 degrees latitude
C. 60 degrees latitude
D. the poles
Equator
*Like a flattened circle around the earth, 26,500ft and -40 over poles, 56,500ft and -70 over equator
Normally the diurnal range of the temperature is greatest at:
A. a coastal location
B. a mid-ocean location
C. an inland location
D. a location with overcast cloud
an inland location
*Diurnal means 24hr or daily variation - range is greatest over a desert
The diurnal variation of temperature is:
A. temperature changes due to seasonal changes
B. temperature pattern over a 24hr period
C. greatest during overcast periods
D. least just after sunrise
temperature pattern over a 24hr period
*Durinal Variation is the amount that temp changes - most over dry inland,
Least over high humidity
Least with overcast because it traps the heat
Solar radiation passing through the atmosphere is:
A. absorbed
B. scattered
C. reflected
D. all of the above
all of the above
On ISA day, you would expect the temperature at an elevation of 4000ft AMSL to be:
A. +15C
B. +23C
C. +11C
D. +7C
+7C
*ISA is +15 at Sea Level, -2C/1000ft
The sea level temp in standard atmosphere is:
A. 20.92C
B. 1013 HPA
C. +15C
D. +30C
+15C
The change of temperature for an increase in altitude known as:
A. lapse rate
B. temperature inversion
C. convection
D. advection
lapse rate
The primary cause of weather is:
A. curvature of the earth
B. the seasons
C. temperature differential
D. rain
temperature differential
A line on the weather chart joining places having the same temperature is called an:
A. isotherm
B. isobar
C. isotach
D. inversion
Isotherm
*isobar = lines of equal pressure
Radiant energy arriving from the sun is termed:
A. photochemical energy
B. insolation
C. insulation
D. light waves
insolation
Our weather is due to the atmosphere being heated mainly by:
A. radiation from the sun
B. insolation from the sun
C. radiation from the earth
D. advection
radiation from the earth
In the standard atmosphere at MSL, temperature, pressure and lapse rate equal respectively:
A. -15C / 1013 HPA / -3C/1000ft
B. +15C / 1013 HPA / 1.5C/1000ft
C. 0C / 1310 HPA / 2C/1000ft
D. +15C / 1013 HPA / 2C/1000ft
+15C / 1013 HPA / 2C/1000ft
A line on a weather map joining lines of equal pressure is called:
A. isotherm
B. contour
C. isogonal
D. isobar
isobar
*isotherm is a line of equal temperature
Atmospheric pressure is reported and recorded on weather charts in terms of:
A. inches of mercury
B. centimetres of mercury
C. millimetres of mercury
D. millibars or hectopascals
millibars or hectopascals
The pressure gradient is:
A. rate of change of pressure with height and is approx. 30ft/HPA
B. generating force of the gradient wind, which then blows along the pressure gradient
C. change of pressure with distance, measured horizontally at right angles to the isobars
D. rate of change of pressure with time and is therefore related to the acceleration of air particles
change of pressure with distance, measured horizontally at right angles to the isobars
The diurnal variation of pressure is:
A. the daily variation of pressure independent of that due to the movement and development ion pressure systems
B. the algebraic sum of the pressure variation over a given period of the day
C. the change of pressure over 24hrs and is measured at 9am each day
D. usually the indication of movement of a nearby system
the daily variation of pressure independent of that due to the movement and development ion pressure systems
Below 5000ft, pressure drops by 1HPA with an ascent of approx:
A. 60ft
B. 40ft
C. 30ft
D. 15ft
30ft
Pressure may be defined as:
A. mass per unit area
B. force per unit area
C. mass per unit volume
D. force per unit volume
force per unit area
The density of air is:
A. directly proportional to pressure and inversely proportional to temperature
B. inversely proportional to pressure and directly proportional to temperature
C. directly proportional to both pressure and temperature
D. inversely proportional to both pressure and temperature
directly proportional to pressure and inversely proportional to temperature
*Directly proportional to pressure
Inversely proportional to temperature and humidity
The sea level pressure in ISA in Australia is:
A. 1013.2 HPA
B. 29.92 in Hg
C. 40 kt
D. +15C
1013.2 HPA
The rate at which atmospheric pressure decreases with altitude in a column of air:
A. is constant regardless of temperature
B. decreases and is dependant on the mean temperature of the column
C. decreases and is not affected by the mean temperature of the column
D. increases and depends on the mean temperature of the column
decreases and is dependant on the mean temperature of the column
Before takeoff for a cross country flight planned to cruise at FL110, the altimeter sub scale should be set to:
A. QFE
B. 1013.2 HPA
C. local QNH if known
D. area QNH
local QNH if known
*question asks before takeoff so 1013 is set through transition
*QFE is station level pressure, if you set QFE on subscale, the main scale will indicate height above or below the reference pressure point - QFE can be found by setting 0ft on the mainscale
What effect does density have on aircraft performance:
A. air is thinner at altitude therefore performance is better
B. performance is better when the density is lower
C. good performance occurs when density is high
D. higher density, poorer performance
good performance occurs when density is high
If the altimeter sub scale is set to 1013, the altimeter will read:
A. pressure height
B. density height
C. altitude
D. elevation
pressure height
While in level flight with the QNH correctly set, the altimeter indicates the aircrafts:
A. precise altitude above MSL
B. actual height above the terrain
C. approximate height above MSL
D. altitude above the departure aerodrome
approximate height above MSL
Aerodrome level pressure is:
A. QFF
B. QNH
C. QNE
D. QFE
QFE
*QNH = area QNH is predicted average sea level pressure for 3hr periods
QFF = meteorological mean sea level pressure
QFE = station level pressure, mainscale will indicate height above the reference pressure point
While at or below 10,000ft, the altimeter sub scale is to be:
A. QFE
B. 1013.2HPA
C. destination local QNH
D. local QNH of a point within 100nm of the aircraft or area QNH
local QNH of a point within 100nm of the aircraft or area QNH
The accepted relationship between pressure in hectopascals and height in the lower layers of the atmosphere is:
A. 30HPA/1ft
B. 1HPA/30 in Hg
C. 1HPA/30ft
D. 1013HPA/36,090ft
1HPA/30ft
What is the relationship between pressure and altitude:
A. increase in altitude results in a decrease in pressure
B. aircraft climbing will experience increased pressure
C. high pressure is experienced at high altitude
D. at high altitudes the air is thin therefore pressure is high
increase in altitude results in a decrease in pressure
The QNH altimeter setting is:
A. height AMSL expressed in hectopascals
B. atmospheric pressure exerted on a particular area
C. sub scale setting at which the altimeter indicates airfield elevation on landing
D. sub scale setting at which the altimeter indicates pressure height
sub scale setting at which the altimeter indicates airfield elevation on landing
When flying from an area of high pressure into lower pressure, the altimeter will:
A. overread
B. underread
C. be unaffected
D. give fluctuating readings
overread
The correction applied to station level pressure to obtain the QNH assumes:
A. the density of a column of air extending down to MSL is independent of temperature at station
B. the density height measure at the station is greater than the pressure height
C. the density of a column of air extending down to MSL is dependent on the temperature at station
D. the density height measure at the station is less than the pressure height
the density of a column of air extending down to MSL is independent of temperature at station
The correction applied to station level pressure to obtain MSL pressure (known as QFF) assumes the density of the column of air extending from the station to MSL:
A. is constant and the same as the outside air density at the station
B. increase with a decrease in height and depends on the outside air temperature at the station
C. is constant and independent of the outside air temperature of the station
D. decrease with a decrease in height and is independent of the outside air temperature at the station
increase with a decrease in height and depends on the outside air temperature at the station
When a parcel of air becomes saturated and condensation occurs:
A. all the water vapour changes to liquid state
B. latent heat is absorbed
C. rain will commence
D. latent heat is released
latent heat is released
Relative humidity is:
A. the percentage degree of saturation
B. the ratio of the amount of water vapour to the amount of air in which its contained
C. the ratio of mass of eater to the mass of dry air in which its held
D. unaffected by changes in temperature
the percentage degree of saturation
The dew point is the temperature:
A. indicated by the wet bulb thermometer in a Stevenson screen
B. to which a sample of moist air must be cooled at constant pressure for it to become saturated
C. defined by the following equation, DP temperature/air temperature = RH
D. at the top of a cloud
to which a sample of moist air must be cooled at constant pressure for it to become saturated
When water droplets in the liquid state freeze:
A. the relative humidity decreases
B. latent heat is released
C. latent heat is absorbed
D. hail will commence to fall
latent heat is released
Relative humidity is measured using a:
A. Hydrometer
B. Barometer
C. Altimeter
D. Psychrometer
Psychrometer
A parcel of air has a temperature of +15C and a RH of 80%. A temperature rise of 10C will cause:
A. rain to form
B. RH to decrease
C. RH to increase
D. condensation
RH to decrease
*As temp increases, RH decreases
The water vapour air in saturated air is:
A. visible sometimes
B. visible if the temperature is low enough
C. visible always
D. invisible always
invisible always
When the temperature and dew point are the same:
A. the atmosphere is stable
B. the atmosphere is unstable
C. dew cannot form
D. the RH is 100%
the RH is 100%
The reading of wet and dry bulbs thermometers at met stations serves to calculate:
A. humidity
B. pressure
C. stability
D. minimum temperature
humidity
Relative humidity is the:
A. ratio of the amount of water vapour present to the amount of water vapour that could be held in a sample of air
B. ration of the mass of water vapour to the total mass of the sample of atmosphere in which it is contained
C. ratio of the mass of water vapour to the mass of dry air with which it is associated
D. percentage volume ratio of the water vepour in a sample of air
ratio of the amount of water vapour present to the amount of water vapour that could be held in a sample of air
When the air temperature at a particular level is higher than that existing at a lower level:
A. the pressure will be low
B. the pressure will be high
C. the air is unstable
D. an inversion exists
an inversion exists
*inversion is when temp increases with altitude
Warm air is rising adiabatically above a ploughed field, surface temp +21C. The DP a the cloud base is +3C. The cloud base and freezing level are respectively:
A. 7500ft and 9500ft
B. 9000ft and 11000ft
C. 9000ft and 10500ft
D. 6000ft and 8000ft
6000ft and 8000ft
If the ELR is between 1.5 and 3C the air is:
A. stable
B. unstable
C. neutrally stable
D. stable for dry air and unstable for saturated air
Stable for dry air and unstable for saturated air
*SED
S - SALR
> stable
E - ELR
> unstable
D - DALR
Above the condensation level, the lapse rate of rising air will:
Reduce from the DALR to the SALR
An inversion results in:
Extremely stable conditions above
Warmer temperatures above a colder layer of air indicates:
An inversion
When ELR is greater than DALR, dry air is:
Unstable
*S >stable> E >unstable> D
DALR is
-3/1000ft
When SALR is greater than ELR, saturated air is:
Stable
*S >stable> E >unstable> D
The actual change in temperature for an increase in altitude is known as:
The environmental lapse rate
Warm air is rising adiabatically above a ploughed field, surface temp 21C. The surface dew point is 3. Allowing for dew point lapse rate, the cloud base and freezing level are:
7500ft and 7000ft
The average rate of decrease in temperature per 1000ft is
2C/1000ft
An adiabatic process is:
Where no heat is transferred into or out of the system
A katabatic wind:
Is a downslope flow of cold air
*when clear night says cool the mountain side by conduction
Surface wind around a low pressure system in the Southern Hemisphere flows:
Clockwise and inwards
If the wind direction changes in a clockwise direction, it is said to:
Veer
Coriolis force in the Southern Hemisphere acts:
At right angles to the direction of the wind, causing a deflection to the left
A land breeze is a wind that blows:
From the land to sea during the night
*Sea breeze blows from the sea during the day
Close isobars mean:
Strong winds
A wind caused by uneven heating in coastal regions flows:
From the sea by day and from the land by night
If the forecast is 030T/20, it will blow:
From 030 true
When flying towards a low in the Southern Hemisphere, an aircraft would experience:
Left drift
*Low winds go clockwise and inwards
Low is called a depression/cyclone
Elongated low is a trough
Within the friction layer with increasing height, the wind:
Backs
If you stand with your back to the wind in the Southern Hemisphere, the region of low pressure:
Will be on your right
The friction layer extends up to about:
3000ft
With the passage of a cold front in the Southern Hemisphere:
The wind backs, temperature falls and pressure rises
*A cold front undercuts warm air and forces it to rise
Cold front generates unstable conditions ahead of it
May result in frontal thunderstorms ahead of it
True or false: Warm fronts always lie along ridges and cold fronts always lie along troughs.
False
A cold front usually lies along a:
Trough of low pressure
A cold air mass is characterised by:
Unstable conditions, cumuliform clouds
*Cold fronts = Cu ahead of it
(cold and cumulus both begin with C)
*Think of me being cold, being unstable and unhappy
*When I’m warm, I’m stable
*Warm fronts = stratus and nimbostratus
A defined boundary between 2 air masses is called:
Front
Warm air masses are characterised by:
Stable with hazy conditions
*Warm front is when warm air replaces the cold air by sliding over the top of it
*Warm air is generally stable, causing stratus clouds with rain from nimbostratus
*Approach of a warm front is high level cloud, then mid level cloud then extensive Ns
*Passage of a warm front marked by:
-Back in wind, rise in temp and pressure fall decreasing
A cold front is a zone where:
Cold air is displacing warm air at the surface
*Think of the angry triangle diagram pushing the warm air up
A warm front is a zone where:
Warm air slides over cold air at the surface
*Warm air rises because it’s less dense so it can’t push the cold air up but it can take it over on top of
With the passage of a warm front in the Southern Hemisphere:
The wind backs, temp rises and pressure fall decreases
*Passage of a warm front, temp rises
*Passage of a cold front, temp falls
Following the passage of a warm front, the most likely weather scenario would be:
Nil significant weather
*Heavy rain when the warm front is passing but nothing after it
The approach of a warm front would be indicated by:
High level cloud, followed by mid level cloud and eventually extensive Ns
Frontal thunderstorms would be triggered:
By the passage of a cold front
*Cold fronts have cumulus cloud ahead of them and can develop into TS with the unstable conditions
*After a warm front is nil significant weather
The north west monsoon:
Brings unstable moist air to darwin
*Ie the wet season
The inter tropic convergence zone is a boundary between:
Airstreams operating in the northern and southern hemispheres
The major hazard of a tropical cyclone to an aircraft in flight is:
Severe turbulence
A strong wind across a mountain range will produce:
Strong down currents on the lee side
(Picture a mountain like a slip n slide and the wind is zipping down the lee)
The cyclone season in Australia is:
November to April
You would expect to encounter the most severe turbulence when flying at a height of 3000ft above the ground at a:
Rapidly moving cold front with unstable air
*Cu clouds ahead of a cold front
Potential thunderstorms
The approach of a tropical revolving storm is heralded by:
Falling pressure with increasing wind speed
The most pronounced thermal turbulence is found:
In the afternoon over land
If the air is unstable in the lower layers only, the following conditions could be expected:
Bumpy with cumulus cloud
The characteristics of warm air masses are:
Stable lapse rate and stratiform cloud
*Warm = stable, stratiform ahead of it
Starts high level, then mid level, then extensive Ns with rain
*Nil significant weather after its passed
*After warm front passing:
-Wind backs, temp rises and pressure fall decreases
Cold streams passing over south eastern Australia are usually unstable because:
The surface which they pass over is warmer than the air
The pressure gradient force acts:
At right angles to the isobars, towards the lower pressure
The strength of the pressure gradient force depends most on:
Spacing of the isobars
*Close isobars = strong winds
Coriolis force explains the tendency of wind to:
Turn left in the southern hemisphere
Surface wind when compared to gradient wind flow is found to be:
Veered to the right and slower
*As altitude increases from the ground, the wind backs and increases - no more friction so it can speed up
Compared to the gradient wind flow, the surface wind over land will have:
Veered by 30degrees and slowed by 2/3rds
*Over the sea it will veer but only slow by 1/3rd
The term geostrophic wind refers to the steady flow of wind:
parallel to straight isobars
*when the Coriolis force is balanced by the pressure gradient force it means isobars are straight
*Gradient wind flows parallel to curved isobars
Anticyclonic flow occurs:
About a high in the southern hemisphere
*Cyclone is clockwise, around a low/depression
Cyclonic flow occurs:
Around a low in the southern hemisphere
*Cyclone = low/depression/clockwise
Katabatic wind will tend to reinforce:
A land breeze
The variations in pressure which normally occur with the passage of a cold front are:
Wind backs, temp drops and pressure rises
A Fohn wind is likely to result in:
Lower humidity on the lee side of the mountain at low level
*Also cloud base will be higher on lee side
Lee side surface temps will be higher
Which statement best describes a squall line:
Low cloud moving rapidly in the warm air infront of a cold front
*Cold front has Cu clouds ahead of it which can form TS and squall lines are TS’s
At which latitude would there be the greatest difference between the actual wind and gradient wind at 5000ft
5 degrees S
A statement which best describes a backing wind is:
It changes direction anticlockwise
*Backing is anticlockwise
*Anticlockwise around a high or anti-cyclone
For a katabatic wind to form, there must be:
A surface inversion
*So the cold air can roll down the side of the hill
Squall lines are most often associated with:
Thunderstorms
Surface friction causes:
A decrease in the Coriolis effect
*Because surface friction decreases wind speed
*Coriolis is 0 at the equator and maximum at the poles
*Stronger the wind, stronger the Coriolis deflection
An aircraft heading directly from a high pressure system to a low pressure system will:
Drift towards the left
*Low = clockwise
High = anticlockwise, draw the patterns to picture it
Conditional stability is said to exist when:
When dry air is stable and saturated air is unstable
*The opposite to the norm:
S >stable> E >unstable> D
Which conditions are most likely to produce radiation fog:
Nil cloud and light winds
During what stage of a thunderstorm would lightning be most frequent:
At the mature stage
Where is hail most likely to be encountered in a thunderstorm
Between 10000ft and 30,000ft
In which conditions are thunderstorms most likely:
Latitudinal heating of a fast moving cold moist air stream
Which of the cloud types are most likely to produce Virga
Thin altostratus
*Virga is rain that doesn’t touch the ground
*thin altostratus is rime icing
*thick altostratus could have clear icing
*Ns is continuous rain
Which is most likely to be encountered in nimbostratus:
Heavy continuous rain
*Thin altostratus is virga
*Ns is also orographic cloud and clear ice is present up to 5000ft above the fzl level
The lifting of fog may be caused by:
An increase in wind strength
*To blow it away
The most common way for cumulus cloud to form is:
Rising air being cooled by expansion
Which phenomena in a TS causes low level wind shear at some distance away from the cell:
Downdrafts
Where are tornadoes most likely to be encountered
With widespread severe thunderstorms
Latitudinal heating of a cold air stream produces:
Instability, possible thunderstorms
*Cu clouds formed by rising air being cooled by expansion
A TS can occur after a cold front has passed because:
The surface which the cold air is passing is warmer than the cold air mass
Advection fog forms when:
Warm air passes over a cold surface
TS are most lilt to form when atmospheric conditions are:
Humid and unstable
A wind blowing up sloping terrain could be:
Anabatic
*Anabatic is when warm air goes up a mountain
A hazard at all levels in a Cb is:
Turbulence
The main hazard posed to aircraft by airframe icing is:
Reduced aerodynamic efficiency
The type of icing likely to be encountered above the freezing level in stratiform cloud is:
Rime ice
*Rime in stratiform, large Cu, thin altostratus, thin altocumulus, stratocumulus
*Clear in Ns, Cb, thick altostratus
The type of icing likely to be encountered above the freezing level in a Cu type cloud is:
Clear ice
The formation of clear ice requires:
Large droplets and an OAT between 0 and -15
The most severe airframe icing is found:
Between 0 and -15 degrees C
*Clear ice from 0 to -10 - large droplets
Rime from -10 to -20 - small droplets
The hazards posed to aircraft around a thunderstorm could be:
A. Icing and hail
B. Icing and turbulence
C. Turbulence and hail
D. Lightning and icing
Turbulence and hail
The minimum OAT where clear airframe icing would be unlikely is:
+5
*from 0 to -10 is usually clear for large droplets
When a TS is in the vicinity of an airport, one hazard preventing aircraft landing and taking off is:
Windshear
Airframe icing is most likely:
With visible moisture at temperatures below freezing
The type of icing likely to be encountered in an orographic cloud when the OAT is -10 would be:
Clear ice
*Orographic cloud is Ns cloud and supercooled rain is present in this cloud type which is clear ice up to 5000ft above the freezing level
The icing experienced when flying through rain in temperatures below freezing would be:
Heavy clear
When avoiding a TS, horizontal separation should be at least:
20nm
While on approach to land, an aircraft encounters an abrupt decrease in the headwind component. The initial effect will be:
A decrease in IAS and an undershoot tendancy
*No wind pushing more against the pitot and no wind keeping you in the air so you undershoot
The most hazardous form of airframe ice is:
Clear ice
Clear icing in Australia is normally associated with the following clouds:
Large cumulus, cumulonimbus, nimbostratus
Before flight, the pilot notices a thin white crystalline deposit over the wings:
Should be removed before attempting to take off
Dangerous icing is frequently found in:
Nimbostratus cloud
*Ns cloud = orographic = large droplets for clear ice
“It is safe to avoid a TS by flying under it”
A. only if you can see through to the other side
B. while the storm is in the mature stage
C. false
D. Only if Virga is present
false
The white crystalline deposit of ice that forms on all exterior surfaces of an aeroplane when water vapour turns directly into ice is called:
Hoar frost
The area which a Tropical Cycle us most likely to form is:
Over the Pacific Ocean at about 15 degrees S
During the nature stage of a tropical cyclone, the central surface pressure:
Remains constant
The temperature at the base of stratocumulus cloud is -1C. The cloud is 2500ft Thi k, the temperature at the cloud tops is -5C. Flight within the cloud is likely to encounter:
Rime ice
In which cloud type is clear ice most likely in flight above the freezing level:
Nimbostratu
In the vicinity of mountain waves, the rotor zone might be located:
Under lenticular clouds
Slant visibility in fog causes:
The runway to be visible from over the top but not in the circuit area or final
The situation which clear icing is most likely is:
Above freezing level on climb in large Cumuliform cloud
The process involved in the formation of hoar frost is:
Deposition of ice directly from water vapour mixed with the air
The set of conditions most likely to produce mountain wave activity are:
A stable layer of air at the top of the ridge
The temperature range most likely to produce rime ice is:
-10 to -20C
Clear ice is most likely to form on an aircraft flying in:
Thick altostratus cloud
The cloud type often associated with mountain wave activities is:
Lenticular or rotor clouds
The most likely cause of turbulence over land on a. hot day is:
Thermal activities
The most dangerous hazard of a mature TS is:
Turbulence
Strong horizontal wind shear can be encountered:
Above a strong surface inversion
The onset of light wind beneath a radiation inversion will cause the inversion to become:
Weaker but deeper
Comparing visibility and turbulence above and below a subsidence inversion, it is found that:
Visibility is greater and turbulence is less above the inversion
There is little vertical development in cloud within the south east trades because of:
The pressure of the trade wind inversion
*because of the presence of the trade wind inversion
The pressure system which gives rise to subsidence inversions is:
Anticyclone
*Anticyclone = high = air moved anticlockwise
Meteorological visibility refers to:
The greatest visibility prevailing over half or more of the horizon
The equatorial trough moves further north than it does south because:
The average surface temperature is higher because of the larger land masses in the northern hemisphere
Low level jet streams can be hazardous because they produce:
Strong horizontal wind shear near the surface
Showers are associated with:
Cumulus
A cloud which forms on the windward slop of a mountain is:
An orographic cloud
The following are classified as mid-level clouds:
Altostratus, altocumulus, altoculumulus lenticularis
The process by which air is cooled to form cloud in a low pressure system is:
Convergence
Heavy continuous rain would most likely be falling from:
Nimbostratus
The following are classified as low clouds:
Cumulus, stratus, nimbostratus
*Alto=mid
*Cirrus=high
Clouds classified as high level clouds are:
Cirrus, cirrocumulus, cirrostratus
Cloud may form when:
Air reaches its dew point temperature
Frontal clouds forms because of:
Upsliding and uplifting effects
If the air is unstable, the following conditions could be expected:
Bumpy with cumulus cloud
Thermal convection currents forming cumulus clouds are caused by:
The heating of the surface on a sunny day
Drizzle would most likely be falling from:
Stratus
Compared to daytime flying conditions, night time meteorological visibility is:
The same
Meterological visibility is reported as the greatest distance an object can be seen:
Over half or more of the horizon expressed in meters
Poor visibility due to smoke haze may occur near industrial areas with:
Anticyclonic weather, light winds and a surface inversion
Radiation fog is normally thickest just after:
Sunrise
The lifting of fog may be caused by:
An increase in wind strength
Radiation fog occurs most frequently with:
Light winds and clear skies at night
Reduced visibility due to dust may be produced by:
Strong surface winds and unstable conditions
If the air is unstable, you can expect:
Bumpy flying conditions and unlimited visibility
A SPECI is:
A report that special conditions exist at the time of a rountine report or that specified changes int he meteorological conditions have taken place
An Area forecast indicates the cloud will be BKN CU. The cloud amount expected is:
5-7 oktas
A report of a significant change in the conditions at an aerodrome is called:
SPECI
A TAF3 validity is:
3 hours
The term CAVOK indicates:
No cloud below 5000ft, vis being 10km or more
The term NOSIG means:
No significant change is expected from the conditions reported in the METAR or SPECI
A pilot encountering in flight weather conditions that significantly differ from those forecast should broadcast a:
Short AIREP
In a TAF, the cloud base is given as a height above:
The aerodrome
A SIGMET is:
Information relating to the occurrence of hazardous phenomena at subsonic cruising levels
A METAR is:
An aerodrome meteorological report
The extent of coverage of a domestic TAF is:
8km from the ARP
GEN 3.5-7
CAVOK means:
Vis is 10km or more with no shallow fog
The statement which correctly describes the presentation of information in a METAR is:
The height of the cloud base is expressed as a 3 figure group
The tropopause is a significant boudanry in the atmosphere. The tropopause is defined as:
It is the division between an atmospheric layer in which temperature generally falls steadily with increasing altitude and a layer in which temperature generally remains constant or increases with increasing altitude
Clear air turbulence can occur in widely different circumstances, but there are some features which generall hold true. It is generally true of a jet stream CAT that:
If CAT is encountered in association with a jet stream, a 4000ft altitude change is likely to be sufficient to leave the area of CAT
Most jet streams are aligned east-west. if CAT is encountered in association with such a jet stream, the area of maximum turbulence likely to be found in relation to the jet stream core is:
Below it and on the polar side
TS occur in 2 fundamental types: frontal and air mass. The differences between frontal and air mass TS are:
Strong downdrafts close to the ground are more likely beneath frontal storms
The conditions most favourable for the formation of sea fog are:
Air flow from an area of warm water to an area of cold water
The conditions which would be most favourable for the formation of a low level jet across southern queensland are:
Early morning, clear sky, a high centred to the west of the great dividing range
The statement which gives the best set of atmospheric conditions required for the formation of TS:
A. Unstable atmosphere through to high levels, some form of lifting mechanism and abundant moisture in the lower layers of the atmosphere
B. Unstable atmosphere close to the ground, some form of lifting mechanism and abundant moisture to considerable depth in the atmosphere
C. conditionally unstable atmosphere in the lower layers, some form of lifting mechanism and abundant moisture in the lower layers of the atmosphere
D. stable atmosphere at all levels, some for of lifting mechanism and abundant moisture to considerable depth in the atmosphere
Unstable atmosphere through to high levels, some form of lifting mechanism and abundant moisture in the lower layers of the atmosphere
You depart an aerodrome with your aircraft altimeter set to the correct QNH. You observe that the aircraft is experiencing left drift. The effect on the altimeter, assuming that the QNH setting is not changed is:
The aircraft is flying towards an area of lower pressure and the altimeter will overread
During a stable approach to land, you encounter sudden difficulty maintaining the desired glide slope and you need to use unusually large variations of power to hold the airspeed within acceptable limits. The type of wind shear encountered would be described as:
Strong
*GEN 3.5-13
A pilot who encounters certain intensities of wind sheer at an uncontrolled aerodrome is obliged to broadcast details of the encounter to all aircraft, the details which should be included are:
Aerodrome, type and degree of shear, altitude of greatest adverse effect
*GEN 3.5-13
The datums used in aerodrome forecasts are:
Cloud height above the aerodrome, wind direction based on true north
The meaning of ‘dry adiabatic lapse rate’:
rate at which the temperature of unsaturated air changes as a parcel of air ascends or descends through the atmosphere (3C/1000ft)
A situation in the atmosphere where the environment temperature increases with height is said to be:
Stable
No ide why?
A strong convergence zone within the equatorial trough would probably lead to:
Both frequent TS and steady rain
RVR is observed for the takeoff and landing direction in use. The point from which this observation would normally be made is:
Touchdown point for the particular runway
During a stable approach to land, you encounter sudden hazardous effects on aircraft controllability and you need to use very large variations of power to hold the airspeed within acceptable limits. The type of windshear is:
Severe
*GEN 3.5-15
The datums used in METARs are:
Cloud base is height above the aerodrome and wind is based on true north
Tropical thunderstorms occurring in the hours just before dawn are more likely to form:
Over the sea
The type of TS generally regarded as having the most severe turbulence is:
Shear
A strong pressure gradient is usually associated with:
Strong winds
During the approach, you find difficult in keep the aircraft to the desired flight path and speed. You observe there are cumulus clouds in the vicinity and there is virga associated with the clouds. The cause of your difficulties during approach is most likely:
Microburst and you report you are experiencing strong windshear
A moist airflow over a mountain range in stable atmospheric conditions is likely to result in:
Lower cloud base on the windward side
The most favourable conditions for a dust storm near Adelaide are:
An approaching cold front with high pressure area to the east
*High=anticyclone=anticlockwise
*Cold front is cumulus clouds and potential TS ahead
Cold air undercuts warm air - unstable
*after passing, wind backs, temp drops, pressure rises
*Dust storms need an unstable atmosphere
*High pressure systems stop fronts moving inland
You are approaching an airfield near the east coast at 1800Z. There is no cloud. The wind at 3000ft is 260/30. The ATIS reports 290/12 and QNH 1004. The most likely explanation for change of wind below 3000ft is:
Frictional effects are confined to below a surface inversion and the wind at 3000ft is unaffected by surface friction
Visibility on a METAR is:
Minimum visibility over half or more of the horizon
An approaching idealised (fast moving) cold front may generally be recognised by:
Broken Cu cloud and rain showers
*BEfore a cold front is Cu, maybe TS
The term best describes an accumulation of airframe icing on an aircraft which may be sufficient to make a change in altitude essential:
Severe
*ENR 1.1-100
The most likely situation for the occurance of radiation fog is:
Anticyclone with no cloud cover
The area of maximum horizontal wind shear associated with a jet stream will normally be found:
To the side of the jet core nearest the pole
The datums used in METARs are:
Cloud base is height above the aerodrome and wind direction on true north
The following phenomena least likely to be associated with a microburst is:
A. virga
B. localised blowing dust at the surface
C. heavy continuous rain from overcast Ns
D. towering Cu
Heavy continuous rain from overcast Ns
The conditions and pre-requisites for a dust storm are:
land surface dry and dusty, wind at least moderate and unstable atmosphere
The day conditions most favourable for formation of radiation fog overnight are:
clear sky, high temperature and high relative humidity
Lenticular clouds are likely to indicate the presence of:
mountain waves
A mature TS is approaching the departure end of the runway in use. The greatest hazard to heavy aircraft attempting to takeoff is:
Downdrafts
A parcel of moist saturated air rises vertically in the atmosphere, the correct statement:
It will cool about 1.5/1000ft
The atmospheric condition where DALR is greater than ELR but SALR is less that ELR is known as:
Conditional stability or conditional instability
*S stable > E > unstable > D
In January, the subtropical jet stream is likely to be located:
Near latitude 30S
Concerning forecasts which CB’s are forecast, FREQ means:
Many, with little or no separation
http://www.bom.gov.au/aviation/data/education/airmet.pdf
Concerning tropical cyclones:
The tend to form over warm seas beyond 5degrees of the equator
A mature cyclone is moving due south in the Southern Hemisphere. The area of worst weather is likely to be located:
South east quadrant
*Front left quarter is always worst
Clear air turbulence is often associated with jet streams. Concerning the relationship between jet streams and CAT:
Probability of encountering CAT is greatest if the jet is curved
*Below the jet on the polar side
You are approaching a westerly jet stream when flying across South Australia at FL390, the temp at 390 is steadily decreasing, you would expect to pass:
Below the jet core
In the vicinity of a westerly jet stream located 30S CAT is liekly to be most severe:
Southern side of the jet, just below the level of the core
*Near poles and below is worse
A MSL analysis shows a cold front between TAS and NZ. Concerning the stream flowing north behind the front:
TS are possible in the stream because the stream will bring cold moist air rapidly over a warmer surface creating instability through latitudinal heating
*passage of a cold front: backing of wind, drop temp, rise pressure
Slant visibility in fog can cause:
Runway to be visible from overhead but not in the circuit or final
Clear icing is most likely:
Above the freezing level on climb in Cu cloud
*large water drops, 0- -10C
The most likely cause of turbulence over land on a hot day is:
Thermal convection
Strong horizontal wind shear would most likely be encountered:
At a strong surface inversion boundary
An aircraft flying south across Australia at FL370 towards a westerly jet stream. The OAT is steading decreasing. In relation to the jet core, you would expext the aircraft to cross the jet stream:
Below the jet core
An aircraft departs an aerodrome and flys towards a microburst located 1km from the upwind threshold of the departure runway. The order of conditions the aircraft would likely experience is:
Increasing headwind and improved performance, decreasing headwind and downdraft, sink, increasing tailwind
The tropopause is a significant boundary in the atmosphere, it’s defined as:
The division between an atmospheric layer in which temperature generally falls steadily with increasing altitude, and a layer which temperature generally remains constant or increases with increasing altitude
CAT can occur in widely different circumstances but there are some features which generally hold true:
If CAT is encountered in association with a jet stream, a 4000ft altitude change is likely sufficient to leave the area of the CAT
Most jet streams are aligned roughly east-west. If CAT is encountered in association with such jet stream, the area of maximum turbulence likely to be found in relation to the jet stream core is:
Below it and on the polar side
TS can occur in 2 fundamental types: frontal and air mass. Regarding the differences between fontal and air mass TS:
Strong down drafts close to the ground aremore likely beneath frontal storms
The set of conditions presenting the greatest threat of clear air frame ice forming is:
Cruise penetration of cumulonimbus cloud with an air temperature of -5C
*Large droplets from 0 to -10
The term most correctly describing an accumulation of airframe icing on an aircraft sufficient to make a change in altitude desirable is:
moderate icing
*ENR 1.1-100
The best description of conditions on board an airline transport passenger aircraft encountering moderate turbulence is:
the aircraft rolls and pitches but remains under control and loose objects move about. the attendants have difficult in walking
*ENR1.1-100
The vis at an aerodrome is reported as 900RVR. As you pass vertically above this airfield at 3000ft you can clearly see the runway below. You make an ILS approach using the standard 3 degree glide slop. The distance from the threshold should you expect to first sight the runway is:
1/2nm
*1000m is 1/2 nm
The set of conditions most favourable for the formation of a thick radiation fog overnight is:
Clear sky, high relative humidity, light winds
The conditions most favourable for the formation of sea fog is:
Airflow from an area of warm water to cold water
The best set of atmospheric conditions for the formation ofTS is:
Unstable atmosphere through to high levels, some form of lifting mechanism and abundant moisture in the lower layers of the atmosphere
When advection fog has developed, the condition which may tend to dissipate or lift the fog into low stratus cloud is:
wind stronger than 15kts
Haze layers are cleared or dispersed by:
Wind or the movement of air
The feature associated with the tropopause is:
An abrupt change in temperature lapse rate
The cloud type associated with violent turbulence and a tendency toward the production of funnel cloud types is:
Cumulonimbus mammatus
A clear area in a line of TS echoes on a wx display radar indicates:
An area where precipitation drops are not detected
When flying over the top of a severe TS, to avoid the risk of severe turbulence, the cloud should be overflown by:
1000ft for each 10kt of windspeed at the cloud top
The condition necessary for the formation of structural icing in flight is:
the presence of visible water
The type of precipitation indicating that supercooled water is present is:
Freezing rain
The type of icing is associated with the smallest size of water droplet similar to that found in low level stratus clouds is:
Rime ice
A necessary condition for the occurrence of a low level temperature inversion wind shear is:
A calm or light wind near the surface and a strong wind just above the inversion
The lowest cloud type in the stationary group associated with a mountain wave is:
Rotor cloud
The action recommended if jet stream turbulence is encountered with a direct headwind or tailwind is to:
Change altitude or course to avoid a possible elongated turbulent area
The action recommended regarding an altitude change to get out of jetstream turbulence is:
descend if ambient temperature is falling
Approximate true altitude is:
Indicated altitude corrected for temperature variation from standard
An elongated area of low pressure is defined as:
Trough
An important characteristic of windshear is:
It may be associated with either a wind shift or a windspeed gradient at any level in the atmosphere
A common location for a temperature inversion is:
Above the tropopause
The condition producing the most frequent type of ground or surface based temperature inversion is:
Terrestrial radiation on a clear, relatively calm night
The facilities provided by ATC radar in regard to storm warning advice are:
Limited weather radar observations at suitably equipped locations
An aircraft is experiencing strong westerly winds while tracking 180 at FL370 over continental Australia. The TAT is increasing. To minimise the risk of encountering CAT, the pilot should:
Climb
*If temp is rising, you’re near the top of the jet
The cause of winds flowing across isobars at an angle rather than parallel to the isobars is:
Surface friction
The type of altitude used when maintaining FL210 is:
Pressure
The altimeter setting local QNH is the value to which the scale of the pressure altimeter is set so the altimeter indicates:
True altitude at field elevation
The OAT is +8 at an elevation of 1350ft and a standard ELR exists. The approximate freezing level is:
5350ft
*8-0 = 8/2 = 4000ft
A feature associated with a temperature inversion is:
A stable layer of air
The type of clouds forming if very stable moist air is forced upslope are:
Stratified clouds with very little vertical development
*Would be Cu clouds if unstable
The general characteristics of unstable air are:
good visibility, showery precipitation and Cu type clouds
*In an unstable atmosphere, good vis because the air movement blows away all the stuff
A characteristic of stable air is:
Stratiform clouds
*Poor vis in stable air bbecause haze lingers and air doesnt move so not Cu clouds building
The type of cloud expected when an unstable air mass is forced to ascend a mountain slope is:
Cloud with extensive vertical development
Characteristics of stable air are:
Poor visibility, steady precipitation, stratus type clouds
Stability characteristics of the atmosphere can be determined from measurement of:
Environmental lapse rate
The structure or type of clouds forming as a result of air being forced to ascend is determined by:
The stability of the air before listing occurs
The variables likely to result in Cu type clouds, good visibility, rain showers, and possible clear type icing in clouds are:
Unstable, moist air and orographic lifting
Unsaturated air flowing upslope will cool at the rate of:
3/1000ft
*DALR = unsaturated
A temperature inversion will normally form only:
In stable air
The beginning of the mature stage of the TS is signalled by:
The start of rain at the surface
*rain and hail generate strong downdrafts while the updrafts are still going causing windshear and severe turbulence
High level clouds are composed mostly of:
Ice crystals
Compared to ISA, the altitude and temperature of the average polar tropopause is:
Lower and warmer
Compared to ISA, the altitude and temperature of the average tropical tropopause is:
Higher and colder
Concerning the height of the tropopause with the passage of a cold front at the surface:
The tropopause is lower after the front
*passage of a cold front is indicated by: backing winds, temp dropping and pressure rising
The zone of transition between 2 air masses of different density is commonly referred to as a:
Front
A private VFR flight is planned for a route entirely over land, a weather forecast need not be obtained unless:
The destination is beyond the vicinity of the departure point.
Lightning strikes on a metal aircraft are:
More likely to be harmful to the instruments than the occupants
An area QNH is routinely issued by the met office every:
3 hours
A VOLMET message is available to a pilot:
Through routine radio broadcasts
Turbulence in a TS cell is greatest:
In the mature stage because of the strong updraft and downdrafts
When the dry bulb temp and dew point temp are the same:
The relative humidity is 100%
From the list of weather situations below, select which would be favourable for the formation of fog:
A. Movement of warm moist air over a cold surface
B. Frontal uplift near a depression
C. Extremely low dew points in a deep southerly stream
D.An anticyclonic circulation of cold dry air over a warm land surface
Movement of warm moist air over a cold surface
Surface friction causes
Increased cross isobar flow
- because wind decreases so coriolis force decreases so wind swings in favour of pressure gradient which is across the isobars
Surface friction causes
Increased cross isobar flow
- because wind decreases so coriolis force decreases so wind swings in favour of pressure gradient which is across the isobars
