Private Pilot - Weather.txt
Card Set Information
Private Pilot - Weather.txt
Private Pilot Weather
Private Pilot - Weather
3381. Every physical process of weather is accompanied by, or is the result of, a
3382. What causes variations in altimeter settings between weather reporting points?
Unequal heating of the Earth's surface.
3448. The development of thermals depends upon
3395. The wind at 5,000 feet AGL is southwesterly while the surface wind is southerly. This difference in direction is primarily due to
friction between the wind and the surface.
3450. Convective circulation patterns associated with sea breezes are caused by
cool, dense air moving inland from over the water.
3383. A temperature inversion would most likely result in which weather condition?
An increase in temperature as altitude is increased.
3384. The most frequent type of ground or surface-based temperature inversion is that which is produced by
terrestrial radiation on a clear, relatively still night.
3397. What is meant by the term "dewpoint''
The temperature to which air must be cooled to become saturated.
3398. The amount of water vapor which air can hold depends on the
3399. Clouds, fog, or dew will always form when
water vapor condenses.
3400. What are the processes by which moisture is added to unsaturated air?
Evaporation and sublimation.
3444. If the temperature/dewpoint spread is small and decreasing, and the temperature is 62 °F, what type weather is most likely to develop?
Fog or low clouds.
3421. The boundary between two different air masses is referred to as a
3422. One of the most easily recognized discontinuities across a front is
a change in temperature.
3423. One weather phenomenon which will always occur when flying across a front is a change in the
3385. Which weather conditions should be expected beneath a low-level temperature inversion layer when the relative humidity is high?
Smooth air, poor visibility, fog, haze, or low clouds.
3403. What measurement can be used to determine the stability of the atmosphere?
Actual lapse rate.
3404. What would decrease the stability of an air mass?
Warming from below.
3405. What is a characteristic of stable air?
3408. What feature is associated with a temperature inversion?
A stable layer of air.
3412. What are characteristics of a moist, unstable air mass?
Cumuliform clouds and showery precipitation.
3413. What are characteristics of unstable air?
Turbulence and good surface visibility.
3414. A stable air mass is most likely to have which characteristic?
Poor surface visibility.
3406. Moist, stable air flowing upslope can be expected to
produce stratus type clouds.
3407. If an unstable air mass is forced upward, what type clouds can be expected?
Clouds with considerable vertical development and associated turbulence.
3424. Steady precipitation preceding a front is an indication of
stratiform clouds with little or no turbulence.
3433. The conditions necessary for the formation of cumulonimbus clouds are a lifting action and
unstable, moist air.
3409. What is the approximate base of the cumulus clouds if the surface air temperature at 1,000 feet MSL is 70 °F and the dewpoint is 48 °F?
6,000 feet MSL.
3410. At approximately what altitude above the surface would the pilot expect the base of cumuliform clouds if the surface air temperature is 82 °F and the dewpoint is 38 °F?
10,000 feet AGL.
3415. The suffix "nimbus", used in naming clouds, means
a rain cloud.
3416. Clouds are divided into four families according to their
3419. What clouds have the greatest turbulence?
3417. An almond or lens-shaped cloud which appears stationary, but which may contain winds of 50 knots or more, is referred to as
a lenticular cloud.
3418. Crests of standing mountain waves may be marked by stationary, lens-shaped clouds known as
standing lenticular clouds.
3420. What cloud types would indicate convective turbulence?
Towering cumulus clouds.
3425. Possible mountain wave turbulence could be anticipated when winds of 40 knots or greater blow
across a mountain ridge, and the air is stable.
3442. Upon encountering severe turbulence, which flight condition should the pilot attempt to maintain?
Level flight attitude.
3434. What feature is normally associated with the cumulus stage of a thunderstorm?
3435. Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
Precipitation beginning to fall.
3436. What conditions are necessary for the formation of thunderstorms?
High humidity, lifting force, and unstable conditions.
3437. During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?
3438. Thunderstorms reach their greatest intensity during the
3939. Thunderstorms which generally produce the most intense hazard to aircraft are
squall line thunderstorms.
3440. A nonfrontal, narrow band of active thunderstorms that often develop ahead of a cold front is a known as a
3441. 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?
3452. Which weather phenomenon is always associated with a thunderstorm?
3426. Where does wind shear occur?
At all altitudes, in all directions.
3427. When may hazardous wind shear be expected?
In areas of low-level temperature inversion, frontal zones, and clear air turbulence.
3428. A pilot can expect a wind-shear zone in a temperature inversion whenever the windspeed at 2,000 to 4,000 feet above the surface is at least
3402. The presence of ice pellets at the surface is evidence that there
is a temperature inversion with freezing rain at a higher altitude.
3429. One in-flight condition necessary for structural icing to form is
3430. In which environment is aircraft structural ice most likely to have the highest accumulation rate?
3956. During an IFR cross-country flight, you pick up rime icing 1/2 inch thick on leading edge of the wing. Visibility is more than 10 miles, winds are 8 knots, temp is 3 C. You decide to:
use a faster than normal approach and landing speed.
3443. What situation is most conducive to the formation of radiation fog?
Warm, moist air over low, flatland areas on clear, calm nights.
3445. In which situation is advection fog most likely to form?
An air mass moving inland from the coast in winter.
3446. What types of fog depend upon wind in order to exist?
Advection fog and upslope fog.
3447. Low-level turbulence can occur and icing can become hazardous in which type of fog?
3401. Which conditions result in the formation of frost?
The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing.
3432. How does frost affect the lifting surfaces of an airplane on takeoff?
Frost may prevent the airplane from becoming airborne at normal takeoff speed.
3206. How will frost on the wings of an airplane affect takeoff performance?
Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability.
3431. Why is frost considered hazardous to flight?
Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.