Cards Return to Set Details

Term What causes variations in altimeter settings between weather reporting points?
Definition Unequal heating of the earth"s surface.AW
Term The wind at 5,000 ft AGL is southwesterly while the surface wind is southerly. This difference in direction is primarily due to
Definition friction between the wind and the surface.AW
Term Convective circulation patterns associated with sea breezes are caused by
Definition cool, dense air moving inland from over the water.AW
Term How will frost on the wings of an airplane affect takeoff performance?
Definition Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability.PHB
Term Every physical process of weather is accompanied by, or is the result of, a
Definition heat exchange.AW
Term A temperature inversion would most likely result in which weather condition?
Definition An increase in temperature as altitude is increased.AW
Term The most frequent type of ground or surface-based temperature inversion is that which is produced by
Definition terrestrial radiation on a clear, relatively still night.AW
Term Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?
Definition Smooth air, poor visibility, fog, haze, or low clouds.AW
Term What is meant by the term "dewpoint"?
Definition The temperature at which air must be cooled to become saturated.AW
Term The amount of water vapor which air can hold depends on the
Definition air temperature.AW
Term Clouds, fog, or dew will always form when
Definition water vapor condenses.AW
Term What are the processes by which moisture is added to unsaturated air?
Definition Evaporation and condensation.AW
Term Which conditions result in the formation of frost?
Definition The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing.AW
Term The presence of ice pellets at the surface is evidence that there
Definition is a temperature inversion with freezing rain at a higher altitude.AW
Term What measurement can be used to determine the stability of the atmosphere?
Definition Actual lapse rate.AW
Term What would decrease the stability of an air mass?
Definition warming from below.AW
Term What is a characteristic of stable air?
Definition Stratiform cloudsAW
Term Moist, stable air flowing upslope can be expected to
Definition produce stratus type clouds.AW
Term IF an unstable air mass is forced upward, what type clouds can be expected?
Definition Clouds with considerable vertical development and associated turbulence.AW
Term What feature is associated with a temperature inversion?
Definition A stable layer of air.
Term What is the approximate base of the cumulus clouds if the surface air temperature at 1,000 ft MSL is 70F and the dewpoint is 48F?
Definition 6,000 ft MSLAW
Term At approximately what altitude above the surface would the pilot expect the base of cumuliform clouds if the surface air temperature is 82F and the dewpoint is 38F?
Definition 10,000 ft AGLAW
Term What are characteristics of a moist, unstable air mass?
Definition Cumuliform clouds and showery precipitation.AW
Term What are characteristics of unstable air?
Definition Turbulence and good surface visibility.AW
Term A stable air mass is most likely to have which characteristic?
Definition Smooth air.AW
Term The suffix "nimbus," used in naming clouds, means
Definition a rain cloud.AW
Term Clouds are divided into four families according to their
Definition height range.AW
Term The boundary between two different air masses is referred to as a
Definition front.AW
Term One of the most easily recognized discontinuities across a front is
Definition a change in temperature.AW
Term One weather phenomenon which will always occur when flying across a front is a change in the
Definition wind direction.AW
Term Steady precipitation preceding a front is an indication of
Definition stratiform clouds with little or no turbulence.AW
Term What situation is most conducive to the formation of radiation fog?
Definition Warm, moise air over low, flatland areas on clear, calm nights.AW
Term If the temperature/dewpoint spread is small and decreasing, and the temperature is 62F, what type weather is most likely to develop?
Definition Fog or low clouds.AW
Term In which situation is advection fog most likely to form?
Definition An air mass moving inland from the coast in winter.AW
Term What types of fog depend upon wind in order to exist?
Definition Advection fog and upslope fog.AW
Term Low-level turbulence can occur and icing can become hazardous in which type of fog?
Definition Steam fog.AW
Term An almond or lens-shaped cloud which appears stationary, but which may contain winds of 50 knots or more, is referred to as
Definition a lenticular cloud.AW
Term Crests of standing mountain waves may be marked by stationary, lens-shaped clouds known as
Definition standing lenticular clouds.AW
Term What clouds have the greatest turbulence?
Definition CumulostratusAW
Term What cloud types would indicate convective turbulence?
Definition Towering cumulus clouds.AW
Term Possible mountain wave turbulence could be anticipated when winds of 40 knots or greater blow
Definition across a mountain ridge, and the air is stable.AW
Term Where does wind shear occur?
Definition At all altitudes, in all directions.AW
Term When may hazardous wind shear be expected?
Definition In areas of low-level temperature inversion, frontal zones, and celar air turbulence.AW
Term A pilot can expected a wind-shear zone in a temperature inversion whenever the windspeed at 2,000 to 4,000 feet above the surface is at least
Definition 25 knots.AW
Term One in-flight condition necessary for structural icing to form is
Definition visible moisture.AW
Term In which environment is aircraft structural ice most likely to have the highest accumulation rate?
Definition Freezing rain.AW
Term Why is frost considered hazardous to flight?
Definition Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.AW
Term How does frost affect the lifting surfaces of an airplane on takeoff?
Definition Frost may prevent the airplane from becoming airborne at normal takeoff speed.AW
Term The conditions necessary for the formation of cumulonimbus clouds are a lifting action and
Definition unstable, moist air.AW
Term What feature is normally associated with the cumulus stage of a thunderstorm?
Definition Continuous updraft.AW
Term Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
Definition Precipitation beginning to fall.AW
Term What conditions are necessary for the formation of thunderstorms?
Definition High humidity, lifting force, and unstable conditions.AW
Term During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?
Definition Dissipating.AW
Term Thunderstorms reach their greatest intensity during the
Definition mature stage.AW
Term Thunderstorms which generally produce the most intense hazard to aircraft are
Definition squall line thunderstorms.AW
Term A nonfrontal, narrow band of active thunderstorms that often develop ahead of a cold front is known as a
Definition squall line.AW
Term If there is thunderstorm activity in the vicinity of an airport at which you plan to land, which hazardous atmospheric phenomenon might be expected on the landing approach?
Definition Wind-shear turbulence.AW
Term Upon encountering severe turbulence, which flight condition should the pilot attempt to maintain?
Definition Level flight attitude.AW
Term Which weather phenomenon is always associated with a thunderstorm?
Definition LightningAW
Term Wingtip vortices are created only when an aircraft is
Definition developing lift.PHB
Term The greatest vortex strength occurs when the generating aircraft is
Definition heavy, clean, and slowPHB
Term Wingtip vortices created by large aircraft tend to
Definition sink below the aircraft generating turbulence.PHB
Term When taking off or landing at an airport where heavy aircraft are operating, one should be particularly alert to the hazards of wingtip vortices because this turbulence tends to
Definition sink into the flightpath of aircraft operating below the aircraft generating the turbulence.PHB
Term The wind condition that requires maximum caution when avoiding wake turbulence on landing is a
Definition light, quartering tailwind.PHB
Term When landing behind a large aircraft, the pilot should avoid wake turbulence by staying
Definition above the large aircraft"s final approach path and landing beyond the large aircraft"s touchdown point.PHB
Term When departing behind a heavy aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft
Definition above and upwind from the heavy aircraft.PHB
Term When landing behind a large aircraft, which procedure should be followed for a vortex avoidance?
Definition Stay above its final approach flightpath all the way to touchdown.
Term How does the wake turbulence vortex circulate around each wingtip?
Definition Outward, upward, and around each tip.PHB