Weather Flashcards
What is the expected duration of an individual microburst?
A) Five minutes with maximum winds lasting approximately 2 to 4 minutes.
B) One microburst may continue for as long as an hour.
C) Seldom longer than 15 minutes from the time the burst strikes the ground until dissipation.
C) Seldom longer than 15 minutes from the time the burst strikes the ground until dissipation.
If severe turbulence is encountered, you should strive to maintain a constant
A) altitude.
B) attitude and appropriate airspeed.
C) constant airspeed and altitude.
B) attitude and appropriate airspeed.
What action is appropriate when encountering the first ripple of reported clear air turbulence (CAT)?
A) Extend flaps to decrease wing loading.
B) Extend gear to provide more drag and increase stability.
C) Adjust airspeed to that recommended for rough air.
C) Adjust airspeed to that recommended for rough air.
The practice developed and accepted by the North American air carrier industry using traditional North American fluids is to ensure that the freeze point of the remaining film is below ambient temperature by at least
A) 10 °F.
B) 20 °F.
C) 20 °C.
B) 20 °F.
Which is an effect of ice, snow, or frost formation on an airplane?
A) Increased stall speed.
B) Increased pitchdown tendencies.
C) Increased angle of attack for stalls.
A) Increased stall speed.
Freezing Point Depressant (FPD) fluids used for deicing
A) provide ice protection during flight.
B) are intended to provide ice protection on the ground only.
C) on the ground, cause no performance degradation during takeoff.
B) are intended to provide ice protection on the ground only.
Test data indicate that ice, snow, or frost having a thickness and roughness similar to medium or coarse sandpaper on the leading edge and upper surface of a wing can
A) reduce lift by as much as 40 percent and increase drag by 30 percent.
B) increase drag and reduce lift by as much as 40 percent.
C) reduce lift by as much as 30 percent and increase drag by 40 percent.
C) reduce lift by as much as 30 percent and increase drag by 40 percent.
Snow on top of deicing or anti-icing fluids
A) need not be considered as adhering to the aircraft.
B) must be considered as adhering to the aircraft.
C) must be considered as adhering to the aircraft, but a safe takeoff can be made as it will blow off.
B) must be considered as adhering to the aircraft.
Freezing Point Depressant (FPD) fluids are highly soluble in water; however,
A) ice is slow to absorb it but fast to melt when in contact with FPD.
B) ice absorbs it very fast but is slow to melt when in contact with it.
C) ice is slow to absorb it, and slow to melt when in contact with it.
C) ice is slow to absorb it, and slow to melt when in contact with it.
Freezing Point Depressant (FPD) fluid residue on engine fan or compressor blades
A) can increase performance and cause stalls or surges.
B) has no affect on engine thrust or power.
C) can decrease performance and cause surging and/or compressor stalls.
C) can decrease performance and cause surging and/or compressor stalls.
The adverse effects of ice, snow, or frost on aircraft performance and flight characteristics include decreased lift and
A) increased thrust.
B) a decreased stall speed.
C) an increased stall speed.
C) an increased stall speed.
Maximum downdrafts in a microburst encounter may be as strong as
A) 1,500 ft/min.
B) 4,500 ft/min.
C) 6,000 ft/min.
C) 6,000 ft/min.
An aircraft that encounters a headwind of 40 knots, within a microburst, may expect a total shear across the microburst of
A) 40 knots.
B) 80 knots.
C) 90 knots.
B) 80 knots.
Which INITIAL cockpit indications should a pilot be aware of when a headwind shears to a calm wind?
A) Indicated airspeed decreases, aircraft pitches up, and altitude decreases.
B) Indicated airspeed increases, aircraft pitches down, and altitude increases.
C) Indicated airspeed decreases, aircraft pitches down, and altitude decreases.
C) Indicated airspeed decreases, aircraft pitches down, and altitude decreases.
Which condition would INITIALLY cause the indicated airspeed and pitch to increase and the sink rate to decrease?
A) Sudden decrease in a headwind component.
B) Tailwind which suddenly increases in velocity.
C) Sudden increase in a headwind component.
C) Sudden increase in a headwind component.
Which INITIAL cockpit indications should a pilot be aware of when a constant tailwind shears to a calm wind?
A) Altitude increases; pitch and indicated airspeed decrease.
B) Altitude, pitch, and indicated airspeed decrease.
C) Altitude, pitch, and indicated airspeed increase.
C) Altitude, pitch, and indicated airspeed increase.
Which wind-shear condition results in a loss of airspeed?
A) Decreasing headwind or tailwind.
B) Decreasing headwind and increasing tailwind.
C) Increasing headwind and decreasing tailwind.
B) Decreasing headwind and increasing tailwind.
Which is a definition of ‘severe wind shear?
A) Any rapid change of horizontal wind shear in excess of 25 knots; vertical shear excepted.
B) Any rapid change in wind direction or velocity which causes airspeed changes greater than 15 knots.
C) Any change of airspeed greater than 20 knots which is sustained for more than 20 seconds.
B) Any rapid change in wind direction or velocity which causes airspeed changes greater than 15 knots.
Doppler wind measurements indicate that the windspeed change a pilot may expect when flying through the peak intensity of a microburst is approximately
A) 15 knots.
B) 25 knots.
C) 45 knots.
C) 45 knots.
How will an increasing tailwind shear affect aircraft performance on takeoff?
A) Airspeed will continue to decrease after the aircraft lifts off.
B) The aircraft will rotate at a slower airspeed and require less runway.
C) An aircraft’s climb performance will increase after rotation.
A) Airspeed will continue to decrease after the aircraft lifts off.
(Refer to appendix 2, figure 144.) When penetrating a microburst, which aircraft will experience an increase in performance without a change in pitch or power?
A) 3.
B) 2.
C) 1.
C) 1.
What is a characteristic of the troposphere?
A) It contains all the moisture of the atmosphere.
B) There is an overall decrease of temperature with an increase of altitude.
C) The average altitude of the top of the troposphere is about 6 miles.
B) There is an overall decrease of temperature with an increase of altitude.
What characterizes a ground-based inversion?
A) Convection currents at the surface.
B) Cold temperatures.
C) Poor visibility.
C) Poor visibility.
What feature is associated with a temperature inversion?
A) A stable layer of air.
B) An unstable layer of air.
C) Air mass thunderstorms.
A) A stable layer of air.
When does minimum temperature normally occur during a 24-hour period?
A) After sunrise.
B) About 1 hour before sunrise.
C) At midnight.
A) After sunrise.
At lower levels of the atmosphere, friction causes the wind to flow across isobars into a low because the friction
A) decreases windspeed and Coriolis force.
B) decreases pressure gradient force.
C) creates air turbulence and raises atmospheric pressure.
A) decreases windspeed and Coriolis force.
Which type wind flows downslope becoming warmer and dryer?
A) Land breeze.
B) Valley wind.
C) Katabatic wind.
C) Katabatic wind.
What is a feature of air movement in a high pressure area?
A) Ascending from the surface high to lower pressure at higher altitudes.
B) Descending to the surface and then outward.
C) Moving outward from the high at high altitudes and into the high at the surface.
B) Descending to the surface and then outward.
Where is the usual location of a thermal low?
A) Over the arctic region.
B) Over the eye of a hurricane.
C) Over the surface of a dry, sunny region.
C) Over the surface of a dry, sunny region.
Freezing rain encountered during climb is normally evidence that
A) a climb can be made to a higher altitude without encountering more than light icing.
B) a layer of warmer air exists above.
C) ice pellets at higher altitudes have changed to rain in the warmer air below.
B) a layer of warmer air exists above.
What temperature condition is indicated if precipitation in the form of wet snow occurs during flight?
A) The temperature is above freezing at flight altitude.
B) The temperature is above freezing at higher altitudes.
C) There is an inversion with colder air below.
A) The temperature is above freezing at flight altitude.
En route at FL 270, the altimeter is set correctly. On descent, a pilot fails to set the local altimeter setting of 30.57. If the field elevation is 650 feet, and the altimeter is functioning properly, what will it indicate upon landing?
A) 585 feet.
B) 1,300 feet.
C) Sea level.
C) Sea level.
What is corrected altitude (approximate true altitude)?
A) Pressure altitude corrected for instrument error.
B) Indicated altitude corrected for temperature variation from standard.
C) Density altitude corrected for temperature variation from standard.
B) Indicated altitude corrected for temperature variation from standard.
What term describes an elongated area of low pressure?
A) Trough.
B) Ridge.
C) Col.
A) Trough.
What is an important characteristic of wind shear?
A) It is primarily associated with the lateral vortices generated by thunderstorms.
B) It usually exists only in the vicinity of thunderstorms, but may be found near a strong temperature inversion.
C) It may be associated with either a wind shift or a windspeed gradient at any level in the atmosphere.
C) It may be associated with either a wind shift or a windspeed gradient at any level in the atmosphere.
Where is a common location for an inversion?
A) At the tropopause.
B) In the stratosphere.
C) At the base of cumulus clouds.
B) In the stratosphere.
Where is a common location for an inversion?
A) At the tropopause.
B) In the stratosphere.
C) At the base of cumulus clouds.
B) In the stratosphere.
Which term applies when the temperature of the air changes by compression or expansion with no heat added or removed?
A) Katabatic.
B) Advection.
C) Adiabatic.
C) Adiabatic.
What is the approximate rate unsaturated air will cool flowing upslope?
A) 3 °C per 1,000 feet.
B) 2 °C per 1,000 feet.
C) 4 °C per 1,000 feet.
A) 3 °C per 1,000 feet.
If the ambient temperature is warmer than standard at FL 350, what is the density altitude compared to pressure altitude?
A) Lower than pressure altitude.
B) Higher than pressure altitude.
C) Impossible to determine without information on possible inversion layers at lower altitudes.
B) Higher than pressure altitude.
If the ambient temperature is colder than standard at FL 310, what is the relationship between true altitude and pressure altitude?
A) They are both the same, 31,000 feet.
B) True altitude is lower than 31,000 feet.
C) Pressure altitude is lower than true altitude.
B) True altitude is lower than 31,000 feet.
Which pressure is defined as station pressure?
A) Altimeter setting.
B) Actual pressure at field elevation.
C) Station barometric pressure reduced to sea level.
B) Actual pressure at field elevation.
Isobars on a surface analysis chart represent lines of equal pressure
A) at the surface.
B) referenced to sea level.
C) at a given atmospheric pressure altitude.
B) referenced to sea level.
At which location does Coriolis force have the least effect on wind direction?
A) At the poles.
B) Middle latitudes (30° to 60°)
C) At the Equator.
C) At the Equator.
How does Coriolis force affect wind direction in the Southern Hemisphere?
A) Causes clockwise rotation around a low.
B) Causes wind to flow out of a low toward a high.
C) Has exactly the same effect as in the Northern Hemisphere.
A) Causes clockwise rotation around a low.
Which conditions result in the formation of frost?
A) The temperature of the collecting surface is at or below freezing and small droplets of moisture are falling.
B) Dew collects on the surface and then freezes because the surface temperature is lower than the air temperature.
C) Temperature of the collecting surface is below the dewpoint and the dewpoint is also below freezing.
C) Temperature of the collecting surface is below the dewpoint and the dewpoint is also below freezing.
What conditions can be expected above if you encounter ice pellets in flight?
A) Thunderstorms.
B) Freezing rain.
C) Snow.
B) Freezing rain.
When will frost most likely form on aircraft surfaces?
A) On clear nights with stable air and light winds.
B) On overcast nights with freezing drizzle precipitation.
C) On clear nights with convective action and a small temperature/dewpoint spread.
A) On clear nights with stable air and light winds.
What is the result when water vapor changes to the liquid state while being lifted in a thunderstorm?
A) Latent heat is released to the atmosphere.
B) Latent heat is transformed into pure energy.
C) Latent heat is absorbed from the surrounding air by the water droplet.
A) Latent heat is released to the atmosphere.
Why should you seek to avoid encountering supercooled rain droplets in flight?
A) They indicate turbulent weather.
B) They will immediately freeze when striking exposed objects.
C) They indicate an inversion dangerous to flight.
B) They will immediately freeze when striking exposed objects.
What is indicated about an air mass if the temperature remains unchanged or decreases slightly as altitude is increased?
A) The air is unstable.
B) A temperature inversion exists.
C) The air is stable.
C) The air is stable.
What weather condition occurs at the altitude where the dewpoint lapse rate and the dry adiabatic lapse rate converge?
A) Cloud bases form.
B) Precipitation starts.
C) Stable air changes to unstable air.
A) Cloud bases form.
Which process causes adiabatic cooling?
A) Expansion of air as it rises.
B) Movement of air over a colder surface.
C) Release of latent heat during the vaporization process.
A) Expansion of air as it rises.
When saturated air moves downhill, its temperature increases
A) at a faster rate than dry air because of the release of latent heat.
B) at a slower rate than dry air because vaporization uses heat.
C) at a slower rate than dry air because condensation releases heat.
B) at a slower rate than dry air because vaporization uses heat.
Which condition is present when a local parcel of air is stable?
A) The parcel of air resists convection.
B) The parcel of air cannot be forced uphill.
C) As the parcel of air moves upward, its temperature becomes warmer than the surrounding air.
A) The parcel of air resists convection.
Convective clouds which penetrate a stratus layer can produce which threat to instrument flight?
A) Freezing rain.
B) Clear air turbulence.
C) Embedded thunderstorms.
C) Embedded thunderstorms.
Which type clouds are indicative of very strong turbulence?
A) Nimbostratus.
B) Standing lenticular.
C) Cirrocumulus.
B) Standing lenticular.
Which event usually occurs after an aircraft passes through a front into the colder air?
A) Temperature/dewpoint spread decreases.
B) Wind direction shifts to the left.
C) Atmospheric pressure increases.
C) Atmospheric pressure increases.
What minimum thickness of cloud layer is indicated if precipitation is reported as light or greater intensity?
A) 4,000 feet thick.
B) 2,000 feet thick.
C) A thickness which allows the cloud tops to be higher than the freezing level.
A) 4,000 feet thick.
Which condition produces weather on the lee side of a large lake?
A) Warm air flowing over a colder lake may produce fog.
B) Cold air flowing over a warmer lake may produce advection fog.
C) Warm air flowing over a cool lake may produce rain showers.
A) Warm air flowing over a colder lake may produce fog.
How can the stability of the atmosphere be determined?
A) Ambient temperature lapse rate.
B) Atmospheric pressure at various levels.
C) Surface temperature/dewpoint spread.
A) Ambient temperature lapse rate.
Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
A) The appearance of an anvil top.
B) The start of rain at the surface.
C) Growth rate of the cloud is at its maximum.
B) The start of rain at the surface.
Where do squall lines most often develop?
A) In an occluded front.
B) Ahead of a cold front.
C) Behind a stationary front.
B) Ahead of a cold front.
Where can the maximum hazard zone caused by wind shear associated with a thunderstorm be found?
A) In front of the thunderstorm cell (anvil side) and on the southwest side of the cell.
B) Ahead of the roll cloud or gust front and directly under the anvil cloud.
C) On all sides and directly under the thunderstorm cell.
C) On all sides and directly under the thunderstorm cell.
Why are downdrafts in a mature thunderstorm hazardous?
A) Downdrafts are kept cool by cold rain which tends to accelerate the downward velocity.
B) Downdrafts converge toward a central location under the storm after striking the surface.
C) Downdrafts become warmer than the surrounding air and reverse into an updraft before reaching the surface.
A) Downdrafts are kept cool by cold rain which tends to accelerate the downward velocity.
What is a difference between an air mass thunderstorm and a steady-state thunderstorm?
A) Air mass thunderstorms produce precipitation which falls outside of the updraft.
B) Air mass thunderstorm downdrafts and precipitation retard and reverse the updrafts.
C) Steady-state thunderstorms are associated with local surface heating.
B) Air mass thunderstorm downdrafts and precipitation retard and reverse the updrafts.
Which type storms are most likely to produce funnel clouds or tornadoes?
A) Air mass thunderstorms.
B) Cold front or squall line thunderstorms.
C) Storms associated with icing and supercooled water.
B) Cold front or squall line thunderstorms.
What would dissipate advection fog that has developed in a coastal area?
A) Wind speed less than 15 knots.
B) Wind speed of 15 knots or more.
C) Converging temperature and dew point.
B) Wind speed of 15 knots or more.
Which conditions are necessary for the formation of upslope fog?
A) Moist, stable air being moved over gradually rising ground by a wind.
B) A clear sky, little or no wind, and 100 percent relative humidity.
C) Rain falling through stratus clouds and a 10- to 25-knot wind moving the precipitation up the slope.
A) Moist, stable air being moved over gradually rising ground by a wind.
When flying over the top of a severe thunderstorm, the cloud should be overflown by at least
A) 1,000 feet for each 10 knots windspeed.
B) 2,500 feet.
C) 500 feet above any moderate to severe turbulence layer.
A) 1,000 feet for each 10 knots windspeed.
What type weather change is to be expected in an area where frontolysis is reported?
A) The frontal weather is becoming stronger.
B) The front is dissipating.
C) The front is moving at a faster speed.
B) The front is dissipating.
Which weather condition is an example of a nonfrontal instability band?
A) Squall line.
B) Advective fog.
C) Frontogenesis.
A) Squall line.
Which atmospheric factor causes rapid movement of surface fronts?
A) Upper winds blowing across the front.
B) Upper low located directly over the surface low.
C) The cold front overtaking and lifting the warm front.
A) Upper winds blowing across the front.
What meteorological conditions can be expected when encountering frontal waves or areas of low pressure?
A) Warm fronts or occluded fronts.
B) Slow-moving cold fronts or stationary fronts.
C) Cold front occlusions.
B) Slow-moving cold fronts or stationary fronts.
What weather difference is found on each side of a “dry line”?
A) Extreme temperature difference.
B) Dewpoint difference.
C) Stratus versus cumulus clouds.
B) Dewpoint difference.
Under what conditions would clear air turbulence (CAT) most likely be encountered?
A) When constant pressure charts show 20-knot isotachs less than 150
NM apart.
B) When constant pressure charts show 60-knot isotachs less than 20
NM apart.
C) When a sharp trough is moving at a speed less than 20 knots.
A) When constant pressure charts show 20-knot isotachs less than 150
NM apart.
What action is recommended when encountering turbulence due to a wind shift associated with a sharp pressure trough?
A) Establish a course across the trough.
B) Climb or descend to a smoother level.
C) Increase speed to get out of the trough as soon as possible.
A) Establish a course across the trough.
In comparison to an approach in a moderate headwind, which is an indication of a possible wind shear due to a decreasing headwind when descending on the glide slope?
A) Less power is required.
B) Higher pitch attitude is required.
C) Lower descent rate is required.
B) Higher pitch attitude is required.
How will the airspeed indicator react if the ram air input to the pitot head is blocked by ice before takeoff, but the drain hole and static port are not?
A) Indication will drop to zero.
B) Indication will rise to the top of the scale.
C) Indication will remain constant but will increase in a climb.
A) Indication will drop to zero.
Which type precipitation is an indication that supercooled water is present?
A) Wet snow.
B) Freezing rain.
C) Ice pellets.
B) Freezing rain.
You are landing at an airport near the coast with a wind shear advisory.
Which is a necessary condition for the occurrence of a low-level temperature inversion wind shear?
A) The temperature differential between the cold and warm layers must be at least 10 °C.
B) A calm or light wind near the surface and a relatively strong wind just above the inversion.
C) A wind direction difference of at least 30° between the wind near the surface and the wind just above the inversion.
B) A calm or light wind near the surface and a relatively strong wind just above the inversion.
Which type frontal system is normally crossed by the jet stream?
A) Cold front.
B) Warm front.
C) Occluded front.
C) Occluded front.
Which action is recommended if jetstream turbulence is encountered with a direct headwind or tailwind?
A) Increase airspeed to get out of the area quickly.
B) Change course to fly on the polar side of the jetstream.
C) Change altitude or course to avoid a possible elongated turbulent area.
C) Change altitude or course to avoid a possible elongated turbulent area.
Which action is recommended regarding an altitude change to get out of jetstream turbulence?
A) Descend if ambient temperature is falling.
B) Descend if ambient temperature is rising.
C) Maintain altitude if ambient temperature is not changing.
A) Descend if ambient temperature is falling.
