WorksheetsGLIEM Section 7: Aviation Weather
Total questions: 148
Worksheet time: 1hrs 14mins
In a thunderstorm, what indicates extreme turbulence on the leading edge of cumulonimbus clouds?
Frequent lightning and roll clouds
Smooth stratiform cloud deck
Virga with no lightning
Calm surface winds
Which condition is necessary for the formation of cumulonimbus clouds?
Stable, dry air
Lifting action with unstable, moist air
Strong surface temperature inversion
Subsiding motion and low humidity
Which thunderstorm stage is associated with continuous updraft?
Mature stage
Dissipating stage
Cumulus stage
Anvil stage
Which event marks the start of the mature stage of a thunderstorm?
Appearance of roll clouds
Start of rain at the Earth's surface
End of lightning activity
Formation of stratiform cloud deck
Which characteristic predominates during the dissipating stage of a thunderstorm?
Continuous updrafts
Start of rain
Predominant downdrafts
Formation of towering cumulus
Outside thunderstorm clouds, how far laterally from severe storms can shear turbulence be encountered?
5 NM
10 NM
20 NM
40 NM
Why should you not attempt to fly under the anvil of a thunderstorm?
Low oxygen levels
Potential for severe and extreme clear air turbulence
Icing only occurs there
Navigation instruments fail below anvils
What is a squall line?
A warm front of stratiform clouds
A non-frontal, narrow band of active thunderstorms
A ridge of high pressure
A line of sea-breeze convergence
Which statement best describes the hazard presented by a squall line to aircraft?
Least intense turbulence of any thunderstorm type
Single most intense steady-state thunderstorm hazard
Weak winds with light rain
Primarily affects visibility but not stability
Which phenomena are commonly associated with squall lines?
Destructive winds
Heavy hail
Tornadoes
Gentle stratiform rain
Airborne weather avoidance radar is designed primarily to identify which areas?
Clear air turbulence
Precipitation
Mountain waves
Temperature inversions
Why can instrument weather conditions occur even when radar does not indicate clouds?
Radar only detects wind shear
Some clouds are not indicated on radar screens
Radar detects only surface precipitation
Radar misreads warm fronts as clear air
How far should intense radar echoes be avoided?
At least 10 NM
At least 20 NM
At least 30 NM
At least 40 NM
Before attempting to fly between intense radar echoes, how much separation should exist between them?
10 NM
20 NM
30 NM
40 NM
Hail as an in-flight hazard is likely to be associated with which cloud type?
Stratus
Cumulonimbus
Cirrus
Nimbostratus
Where may hailstones be encountered relative to a thunderstorm?
Only within the rain shaft
Only directly under the storm center
In clear air several miles from a thunderstorm
Only above 15,000 ft AGL
When flying near thunderstorms, where should pilots anticipate possible hail especially?
Above the warm front
Beneath the anvil of a large cumulonimbus
On the leeward side of mountains
Within stratiform layers
As a warm or cold front is about to pass, what happens to rain falling from the warmer air into air at or below 32∘F ?
It evaporates before reaching the surface
It freezes as it falls
It warms the surface air
It turns to graupel after melting
As freezing rain continues to fall, what does it turn into?
Snow
Ice pellets
Supercooled drizzle
Hailstones
What do ice pellets indicate about conditions aloft?
Snow at lower altitude
Freezing rain at a higher altitude
Dry adiabatic lapse rate
Strong mountain waves
What caution is advised when flying in or around freezing conditions, especially with autopilot engaged?
Reduce airspeed to minimum
Extreme vigilance should be exercised
Disable pitot heat
Descend immediately below 10,000 ft
During climbs or cruise with autopilot engaged in freezing conditions, what behavior can lead to a stall?
Autopilot disengages at random
Autopilot holds vertical speed or altitude regardless of deicing function
Autopilot increases bank angle automatically
Autopilot limits angle of attack
What does light turbulence typically cause?
Large altitude changes with loss of control
Slight, erratic changes in altitude and/or attitude
No noticeable motion
Structural damage
How does moderate turbulence affect aircraft control?
Control becomes impossible
Aircraft control remains positive despite changes in altitude and/or attitude
Only attitude changes occur
Only altitude changes occur with no control impact
Where should moderate turbulence be expected in terms of vertical wind shear?
Less than 2 kt per 1,000 ft
3 kt per 1,000 ft
Exceeds 5 kt per 1,000 ft
Exactly 10 kt per 1,000 ft
Clear air turbulence (CAT) is typically found where and is not associated with which cloud type?
Below 5,000 ft AGL; nimbostratus
Above 15,000 ft AGL; cumuliform cloudiness
Near the surface; cirrus
At mountaintop; stratiform cloudiness
When wind flows over mountain ranges, how does it move relative to the slopes?
Down the windward, up the leeward
Up the windward, down the leeward
Uniform across both sides
Only along ridgelines
Which hazard may affect a pilot approaching mountainous terrain from the leeward side?
Forced into upward-flowing air by windward slope
Forced into the side of the mountain by downward-flowing air
No effect due to laminar flow
Only icing concerns
Under what conditions should wave formation be expected in mountainous areas?
Unstable air with light winds
Stable air at mountaintop altitude with winds of at least 20 kt across the mountaintop
Surface inversion with calm winds
Thunderstorms directly over the peak
What is the most dangerous feature of mountain waves?
Strong tailwinds on the windward side
Turbulent areas in and below rotor clouds
Smooth laminar flow above the crest
Rapid warming on the leeward side
When are convective currents most active?
Cold winter mornings with strong winds
Warm summer afternoons when winds are light
During nocturnal inversions
Only near coastlines
What defines wind shear?
Gradual change in wind over large areas
Change in wind direction and/or speed within a very short distance in the atmosphere
Only vertical wind speed change
Only horizontal directional change
At what levels and orientations can wind shear be present?
Only near the surface in the horizontal
Any level, in both horizontal and vertical directions
Only above 15,000 ft in the vertical
Only within thunderstorms
When is hazardous wind shear commonly encountered?
During light winds and clear skies
Periods of strong temperature inversion and near thunderstorms
Only above mountains
Only over oceans
Which situation can produce low-level wind shear?
Low-level temperature inversion with strong winds above the inversion
Uniform temperature profile and calm winds
Cold front passage with no inversion
Sea breeze circulation
During an approach, what may indicate possible wind shear?
Stable power setting and constant vertical velocity
Changes in the power and vertical velocity required to remain on the proper glide path
Increase in groundspeed with constant indicated airspeed
Only variations in lateral alignment
What is the effect of a sudden decrease in headwind during approach?
Gain in indicated airspeed equal to the increase in wind velocity
Loss of indicated airspeed equal to the decrease in wind velocity
No effect on indicated airspeed
Immediate climb without control input
When approaching for landing with possible wind shear or convective turbulence indicated, what should you do to avoid stalling?
Maintain normal approach airspeed
Reduce airspeed to minimum
Increase approach airspeed slightly above normal
Extend flaps fully regardless of speed
Every physical process of weather is accompanied by or is the result of
heat exchange.
the movement of air.
a pressure differential.
Moisture is added to a parcel of air by
sublimation and condensation.
evaporation and condensation.
evaporation and sublimation.
Why does the wind have a tendency to flow parallel to the isobars above the friction level?
Coriolis force tends to counterbalance the horizontal pressure gradient.
Coriolis force acts perpendicular to a line connecting the highs and lows.
Friction of the air with the Earth deflects the air perpendicular to the pressure gradient.
In the Northern Hemisphere, the wind is deflected to the
right by Coriolis force.
right by surface friction.
left by Coriolis force.
With regard to windflow patterns shown on surface analysis charts; when the isobars are
close together, the pressure gradient force is slight and wind velocities are weaker.
not close together, the pressure gradient force is greater and wind velocities are stronger.
close together, the pressure gradient force is greater and wind velocities are stronger.
What causes wind?
The Earth’s rotation.
Air mass modification.
Pressure differences.
Which is true regarding a cold front occlusion? The air ahead of the warm front
is colder than the air behind the overtaking cold front.
is warmer than the air behind the overtaking cold front.
has the same temperature as the air behind the overtaking cold front.
You have delayed your flight to allow a fast moving cold front to clear your destination airport before your arrival. What type of flying conditions would you expect after the front has passed?
A fast moving squall line with high winds and thunderstorms.
Clear skies with gusty, turbulent winds and cooler temperatures.
Low clouds, reduced visibility and showery, misty conditions.
On Surface Analysis Charts, widely spaced isobars indicate a
weak pressure gradient.
strong pressure gradient.
relatively turbulent wind.
While flying cross-country in the Northern Hemisphere, you experience a continuous left crosswind which is associated with a major wind system. This indicates that you
are flying toward an area of generally unfavorable weather conditions.
have flown from an area of unfavorable weather conditions.
cannot determine weather conditions without knowing pressure changes.
Which is true with respect to a high- or low-pressure system?
A high-pressure area or ridge is an area of rising air.
A low-pressure area or trough is an area of descending air.
A high-pressure area or ridge is an area of descending air.
Which is true regarding high- or low-pressure systems?
A high-pressure area or ridge is an area of rising air.
A low-pressure area or trough is an area of rising air.
Both high- and low-pressure areas are characterized by descending air.
When flying into a low-pressure area in the Northern Hemisphere, the wind direction and velocity will be from the
left and decreasing.
left and increasing.
right and decreasing.
What prevents air from flowing directly from high-pressure areas to low-pressure areas?
Coriolis force.
Surface friction.
Pressure gradient force.
The general circulation of air associated with a high-pressure area in the Northern Hemisphere is
outward, downward, and clockwise.
outward, upward, and clockwise.
inward, downward, and clockwise.
The wind system associated with a low-pressure area in the Northern Hemisphere is
an anticyclone and is caused by descending cold air.
a cyclone and is caused by Coriolis force.
an anticyclone and is caused by Coriolis force.
There is a high pressure system that is located north of your planned route in the Northern Hemisphere on a west to east cross-country flight. To take advantage of favorable winds, you would plan your route
on the north side of the high pressure area.
on the south side of the high pressure area.
through the middle of the high pressure area.
During the winter months in the middle latitudes, the jet stream shifts toward the
north and speed decreases.
south and speed increases.
north and speed increases.
The strength and location of the jet stream is normally
weaker and farther north in the summer.
stronger and farther north in the winter.
stronger and farther north in the summer.
A common location of clear air turbulence is
in an upper trough on the polar side of a jet stream.
near a ridge aloft on the equatorial side of a high-pressure flow.
south of an east/west oriented high-pressure ridge in its dissipating stage.
A strong wind shear can be expected
in the jetstream front above a core having a speed of 60 to 90 knots.
if the 5°C isotherms are spaced between 7° to 10° of latitude.
on the low-pressure side of a jetstream core where the speed at the core is stronger than 110 knots.
The jet stream and associated clear air turbulence can sometimes be visually identified in flight by
dust or haze at flight level.
long, thin streaks of cirrus clouds.
a constant outside air temperature.
Which type of jetstream can be expected to cause the greater turbulence?
A straight jetstream associated with a low-pressure trough.
A curving jetstream associated with a deep low-pressure trough.
A jetstream occurring during the summer at the lower latitudes.
Which feature is associated with the tropopause?
Constant height above the Earth.
Abrupt change in temperature lapse rate.
Absolute upper limit of cloud formation.
What is the standard temperature at 10,000 feet?
-5°C
-15°C
+5°C
What are the standard temperature and pressure values for sea level?
15°C and 29.92 in Hg
59°F and 1013.2 mb
15°C and 29.92 mb
Which is true regarding actual air temperature and dew point temperature spread? The temperature spread
decreases as the relative humidity decreases.
decreases as the relative humidity increases.
increases as the relative humidity increases.
What is the standard temperature at 20,000 feet?
-15°C
-20°C
-25°C
What is the standard temperature at 6,500 feet?
15°C
2°C
38°F
An increase in temperature with an altitude increase
is an indication of an inversion.
denotes the beginning of the stratosphere.
means a cold front passage.
Which cloud types would indicate convective turbulence?
Cirrus clouds.
Nimbostratus clouds.
Towering cumulus clouds.
What is the approximate base of the cumulus clouds if the temperature at 2,000 feet MSL is 10°C and the dew point is 1°C?
3,000 feet MSL.
4,000 feet MSL.
6,000 feet MSL.
What determines the structure or type of clouds which will form as a result of air being forced to ascend?
The method by which the air is lifted.
The stability of the air before lifting occurs.
The relative humidity of the air after lifting occurs.
Which are characteristics of a cold air mass moving over a warm surface?
Cumuliform clouds, turbulence, and poor visibility.
Cumuliform clouds, turbulence, and good visibility.
Stratiform clouds, smooth air, and poor visibility.
Which combination of weather-producing variables would likely result in cumuliform-type clouds, good visibility, and showery rain?
Stable, moist air and orographic lifting.
Unstable, moist air and orographic lifting.
Unstable, moist air and no lifting mechanism.
Virga is best described as
streamers of precipitation trailing beneath clouds which evaporate before reaching the ground.
wall cloud torrents trailing beneath cumulonimbus clouds which dissipate before reaching the ground.
turbulent areas beneath cumulonimbus clouds.
The presence of standing lenticular altocumulus clouds is a good indication of
lenticular ice formation in calm air.
very strong turbulence.
heavy icing conditions.
As you approach an airport to land, you observe a convective cloud over the airport with virga below it. This could indicate
smooth air.
heavy rain showers.
the presence of a microburst.
Cumulus clouds often indicate
possible turbulence.
a temperature inversion.
a dry adiabatic lapse rate.
Clouds with extensive vertical development over mountainous terrain are a sign of
a dry adiabatic lapse rate.
a stable air mass.
an unstable air mass.
The stability of an air mass can usually be determined by
the height of the tropopause.
measuring the dry adiabatic lapse rate.
cloud types and the type of precipitation.
In what ways do advection fog, radiation fog, and steam fog differ in their formation or location?
Radiation fog is restricted to land areas; advection fog is most common along coastal areas; steam fog forms over a water surface.
Advection fog deepens as windspeed increases up to 20 knots; steam fog requires calm or very light wind; radiation fog forms when the ground or water cools the air by radiation.
Steam fog forms from moist air moving over a colder surface; advection fog requires cold air over a warmer surface; radiation fog is produced by radiational cooling of the ground.
Fog produced by frontal activity is a result of saturation due to
nocturnal cooling.
adiabatic cooling.
evaporation of precipitation.
Which in-flight hazard is most commonly associated with warm fronts?
Advection fog.
Radiation fog.
Precipitation-induced fog.
A situation most conducive to the formation of advection fog is
a light breeze moving colder air over a water surface.
an air mass moving inland from the coastline during the winter.
a warm, moist air mass settling over a cool surface under no-wind conditions.
Advection fog has drifted over a coastal airport during the day. What may tend to dissipate or lift this fog into low stratus clouds?
Nighttime cooling.
Surface radiation.
Wind 15 knots or stronger.
What lifts advection fog into low stratus clouds?
Nighttime cooling.
Dryness of the underlying land mass.
Surface winds of approximately 15 knots or stronger.
Which conditions are favorable for the formation of a surface based temperature inversion?
Clear, cool nights with calm or light wind.
Area of unstable air rapidly transferring heat from the surface.
Broad areas of cumulus clouds with smooth, level bases at the same altitude.
With respect to advection fog, which statement is true?
It is slow to develop and dissipates quite rapidly.
It forms almost exclusively at night or near daybreak.
It can appear suddenly during day or night, and it is more persistent than radiation fog.
Temperature and radiation variations over land with a clear sky typically lead to
minimum temperature occurring after sunrise
outgoing terrestrial radiation peaking at noon
temperature reaching a maximum closer to noon than to sunset
Penetrating fog while flying an approach at night, you might experience the illusion of
pitching up
flying at a lower altitude
constant turning
What are the characteristics of stable air?
Good visibility; steady precipitation; stratus clouds
Poor visibility; steady precipitation; stratus clouds
Poor visibility; intermittent precipitation; cumulus clouds
Which would decrease the stability of an air mass?
Warming from below
Cooling from below
Decrease in water vapor
What is a characteristic of stable air?
Stratiform clouds
Fair weather cumulus clouds
Temperature decreases rapidly with altitude
Which would increase the stability of an air mass?
Warming from below
Cooling from below
Decrease in water vapor
Which is a characteristic of stable air?
Cumuliform clouds
Excellent visibility
Restricted visibility
Which is a characteristic typical of a stable air mass?
Cumuliform clouds
Showery precipitation
Continuous precipitation
What type of weather can one expect from moist, unstable air, and very warm surface temperature?
Fog and low stratus clouds
Continuous heavy precipitation
Strong updrafts and cumulonimbus clouds
A moist, unstable air mass is characterized by
poor visibility and smooth air
cumuliform clouds and showery precipitation
stratiform clouds and continuous precipitation
If clouds form as a result of very stable, moist air being forced to ascend a mountain slope, the clouds will be
cirrus type with no vertical development or turbulence
cumulus type with considerable vertical development and turbulence
stratus type with little vertical development and little or no turbulence
The formation of either predominantly stratiform or predominantly cumuliform clouds is dependent upon the
source of lift
stability of the air being lifted
temperature of the air being lifted
When an air mass is stable, which of these conditions is most likely to exist?
Numerous towering cumulus and cumulonimbus clouds
Moderate to severe turbulence at the lower levels
Smoke, dust, haze, etc., concentrated at the lower levels with resulting poor visibility
Which is true regarding the development of convective circulation?
Cool air must sink to force the warm air upward
Warm air is less dense and rises on its own accord
Warmer air covers a larger surface area than the cool air; therefore, the warmer air is less dense and rises
When conditionally unstable air with high-moisture content and very warm surface temperature is forecast, one can expect what type of weather?
Strong updrafts and stratominbus clouds
Restricted visibility near the surface over a large area
Strong updrafts and cumulonimbus clouds
Convective circulation patterns associated with sea breezes are caused by
water absorbing and radiating heat faster than the land
land absorbing and radiating heat faster than the water
cool and less dense air moving inland from over the water, causing it to rise
The difference found by subtracting the temperature of a parcel of air theoretically lifted from the surface to 500 millibars and the existing temperature at 500 millibars is called the
lifted index
negative index
positive index
From which measurement of the atmosphere can stability be determined?
Atmospheric pressure
The ambient lapse rate
The dry adiabatic lapse rate
The conditions necessary for the formation of stratiform clouds are a lifting action and
unstable, dry air
stable, moist air
unstable, moist air
What are the characteristics of an unstable atmosphere?
A cool, dry air mass
A warm, humid air mass
Descending air in the northern hemisphere
What visible signs indicate extreme turbulence in thunderstorms?
Base of the clouds near the surface, heavy rain, and hail
Low ceiling and visibility, hail, and precipitation static
Cumulonimbus clouds, very frequent lightning, and roll clouds
What feature is normally associated with the cumulus stage of a thunderstorm?
Roll cloud
Continuous updraft
Beginning of rain at the surface
The most severe weather conditions, such as destructive winds, heavy hail, and tornadoes, are generally associated with
slow-moving warm fronts which slope above the tropopause
squall lines
fast-moving occluded fronts
The conditions necessary for the formation of cumulonimbus clouds are a lifting action and
unstable, dry air
stable, moist air
unstable, moist air
Which statement is true regarding squall lines?
They are always associated with cold fronts
They are slow in forming, but rapid in movement
They are nonfrontal and often contain severe, steady-state thunderstorms
During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?
Mature
Developing
Dissipating
Which statement is true concerning squall lines?
They form slowly, but move rapidly.
They are associated with frontal systems only.
They offer the most intense weather hazards to aircraft.
Which is accurate regarding turbulence associated with thunderstorms?
Outside the clouds, shear turbulence can be encountered 50 miles laterally from a severe storm.
Shear turbulence is encountered only inside cumulonimbus clouds or within a 5-mile radius of them.
Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm.
Select the true statement pertaining to the life cycle of a thunderstorm.
Updrafts continue to develop throughout the dissipating stage of a thunderstorm.
The beginning of rain at the Earth's surface indicates the mature stage of the thunderstorm.
The beginning of rain at the Earth's surface indicates the dissipating stage of the thunderstorm.
Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
The start of rain.
The appearance of an anvil top.
Growth rate of cloud is maximum.
Which is true regarding the use of airborne weather-avoidance radar for the recognition of certain weather conditions?
The radar scope provides no assurance of avoiding instrument weather conditions.
The avoidance of hail is assured when flying between and just clear of the most intense echoes.
The clear area between intense echoes indicates that visual sighting of storms can be maintained when flying between the echoes.
What minimum distance should exist between intense radar echoes before any attempt is made to fly between these thunderstorms?
20 miles.
30 miles.
40 miles.
Which situation would most likely result in freezing precipitation? Rain falling from air which has a temperature of
32°F or less into air having a temperature of more than 32°F.
0°C or less into air having a temperature of 0°C or more.
more than 32°F into air having a temperature of 32°F or less.
What course of action should the pilot take if encountering freezing rain?
Climb because the temperature is warmer at a higher altitude.
Descend because the temperature is warmer at a lower altitude.
No change is necessary if all anti-ice/deice equipment is working.
Hail is most likely to be associated with
cumulus clouds.
cumulonimbus clouds.
stratocumulus clouds.
The greatest threats to an aircraft operating in the vicinity of thunderstorms are:
thunder and heavy rain.
hail and turbulence.
precipitation static and low visibility.
If airborne radar is indicating an extremely intense thunderstorm echo, this thunderstorm should be avoided by a distance of at least
20 miles.
10 miles.
5 miles.
Ice pellets encountered during flight normally are evidence that
a warm front has passed.
a warm front is about to pass.
there are thunderstorms in the area.
Which statement is true concerning the hazards of hail?
Hail damage in horizontal flight is minimal due to the vertical movement of hail in the clouds.
Rain at the surface is a reliable indication of hail aloft.
Hailstones may be encountered in clear air several miles from a thunderstorm.
Ice pellets encountered during flight are normally evidence that
a cold front has passed.
there are thunderstorms in the area.
freezing rain exists at higher altitude.
What is indicated if ice pellets are encountered at 8,000 feet?
Freezing rain at higher altitude.
You are approaching an area of thunderstorms.
You will encounter hail if you continue your flight.
Thunderstorms identified as severe or giving an intense radar echo should be avoided by what distance?
5 miles.
At least 25 miles.
At least 20 miles.
On initial climbout after takeoff and with the autopilot engaged, you encounter icing conditions. In this situation you can expect
ice to accumulate on the underside of the wings due to the higher AOA.
the autopilot to hold the vertical speed, if the anti-icing boots are working.
the increased airflow under the wings to prevent the accumulation of ice.
You are avoiding a thunderstorm that is in your flightpath. You are over 20 miles from the cell; however, you are under the anvil of the cell. Is this a hazard?
No, you are at a safe distance from the cell.
Yes, hail can be discharged from the anvil.
Yes, this is still in the area of dissipation.
Airborne weather radar is installed to help the pilot
penetrate weather between storm cells.
avoid severe weather.
avoid storm turbulence and hail.
A pilot reporting turbulence that momentarily causes slight, erratic changes in altitude and/or attitude should report it as
light chop.
light turbulence.
moderate turbulence.
When turbulence causes changes in altitude and/or attitude, but aircraft control remains positive, that should be reported as
light.
severe.
moderate.
Turbulence that is encountered above 15,000 feet AGL not associated with cumuliform cloudiness, including thunderstorms, should be reported as
severe turbulence.
clear air turbulence.
convective turbulence.
The minimum vertical wind shear value critical for probable moderate or greater turbulence is
4 knots per 1,000 feet.
5 knots per 1,000 feet.
8 knots per 1,000 feet.
One of the most dangerous features of mountain waves is the turbulent areas in and
below rotor clouds.
above rotor clouds.
below lenticular clouds.
The conditions most favorable to wave formation over mountainous areas are a layer of
stable air at mountaintop altitude and a wind of at least 20 knots blowing across the ridge.
unstable air at mountaintop altitude and a wind of at least 20 knots blowing across the ridge.
moist, unstable air at mountaintop altitude and a wind of less than 5 knots blowing across the ridge.
When flying low over hilly terrain, ridges, or mountain ranges, the greatest potential danger from turbulent air currents will usually be encountered on the
leeward side when flying with a tailwind.
leeward side when flying into the wind.
windward side when flying into the wind.
Convective currents are most active on warm summer afternoons when winds are
light.
moderate.
strong.
During departure, under conditions of suspected low-level wind shear, a sudden decrease in headwind will cause
a loss in airspeed equal to the decrease in wind velocity.
a gain in airspeed equal to the decrease in wind velocity.
no change in airspeed, but groundspeed will decrease.
During an approach, the most important and most easily recognized means of being alerted to possible wind shear is monitoring the
amount of trim required to relieve control pressures.
heading changes necessary to remain on the runway centerline.
power and vertical velocity required to remain on the proper glidepath.
The Low Level Wind Shear Alert System (LLWAS) provides wind data and software processes to detect the presence of a
rotating column of air extending from a cumulonimbus cloud.
change in wind direction and/or speed within a very short distance above the airport.
downward motion of the air associated with continuous winds blowing with an easterly component due to the rotation of the Earth.
What is an important characteristic of wind shear?
It is present at only lower levels and exists in a horizontal direction.
It is present at any level and exists in only a vertical direction.
It can be present at any level and can exist in both a horizontal and vertical direction.
Low-level wind shear may occur when
surface winds are light and variable.
there is a low-level temperature inversion with strong winds above the inversion.
surface winds are above 15 knots and there is no change in wind direction and windspeed with height.
Hazardous wind shear is commonly encountered
near warm or stationary frontal activity.
when the wind velocity is stronger than 35 knots.
in areas of temperature inversion and near thunderstorms.
If a temperature inversion is encountered immediately after takeoff or during an approach to a landing, a potential hazard exists due to
wind shear.
strong surface winds.
strong convective currents.
GIVEN: Winds at 3,000 feet AGL 30 kts; Surface winds Calm. While on approach for landing, under clear skies with convective turbulence a few hours after sunrise, one should
increase approach airspeed slightly above normal to avoid stalling.
keep the approach airspeed at or slightly below normal to compensate for floating.
not alter the approach airspeed, these conditions are nearly ideal.
