Weather Theory

Question 1

What effect, if any, does high humidity have on aircraft performance?

Answer 1

It decreases performance.

Question 2

What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why?

Answer 2

Efficiency is reduced because the propeller exerts less force at high density altitudes than at low density altitudes.

Question 3

Every physical process of weather is accompanied by, or is the result of, a

Answer 3

heat exchange.

The sun (or heat exchange) is the primary reason for every physical process of weather on the planet. Watch the “Circulation Pattern” video for more information.

Question 4

Which of the following considerations is more relevant to a Remote PIC when evaluating unmanned aircraft performance?

Answer 4

Current weather conditions.

Question 5

How would high density altitude affect the performance of a small unmanned aircraft?

Answer 5

Decreased performance.

Question 6

What effect does high density altitude have on the efficiency of a UA propeller?

Answer 6

Propeller efficiency is decreased.

Question 7

What are the standard temperature and pressure values for sea level?

Answer 7

15°C and 29.92” Hg.

Question 8

Which combination of atmospheric conditions will reduce aircraft takeoff and climb performance?

Answer 8

High temperature, high relative humidity, and high density altitude.

Question 9

You are flying near mountains, and there are lenticular clouds. What kind of weather should you expect?

Answer 9

very rough air/turbulence.

Question 10

The amount of water vapor which air can hold depends on the

Answer 10

air temperature.

Question 11

What clouds have the greatest turbulence?

Answer 11

Cumulonimbus.

Question 12

The suffix “nimbus,” used in naming clouds, means

Answer 12

a rain cloud.

Question 13

Convective circulation patterns associated with sea breezes are caused by

Answer 13

cool, dense air moving inland from over the water.

Question 14

Low-level turbulence can occur and icing can become hazardous in which type of fog?

Answer 14

Steam fog.

Question 15

While operating around buildings, the Remote Pilot in Command should be aware of the creation of wind gusts that

Answer 15

change rapidly in direction and speed causing turbulence.

Question 16

What situation is most conducive to the formation of radiation fog?

Answer 16

Warm, moist air over low, flatland areas on clear, calm nights.

Question 17

In which situation is advection fog most likely to form?

Answer 17

An air mass moving inland from the coast in winter.

Question 18

What types of fog depend upon wind in order to exist?

Answer 18

Advection fog and upslope fog.

Question 19

What is meant by the term “dewpoint”?

Answer 19

The temperature to which air must be cooled to become saturated.

Question 20

What cloud types would indicate convective turbulence?

Answer 20

Towering cumulus clouds.

Question 21

An air mass moving inland from the coast in winter is likely to result in

Answer 21

fog.

Question 22

What situation is most conducive to the formation of radiation fog?

Answer 22

Warm, moist air over low, flatland areas on clear, calm nights.

Question 23

What conditions are necessary for the formation of thunderstorms?

Answer 23

High humidity, lifting force, and unstable conditions.

Question 24

A stable air mass is most likely to have which characteristic?

Answer 24

Poor surface visibility.

Question 25

One of the most easily recognized discontinuities across a front is

Answer 25

a change in temperature.

Question 26

The boundary between two different air masses is referred to as a

Answer 26

front.

Question 27

The conditions necessary for the formation of cumulonimbus clouds are a lifting action and

Answer 27

unstable, moist air.

Question 28

One in-flight condition necessary for structural icing to form is

Answer 28

visible moisture.

Question 29

What is a characteristic of stable air?

Answer 29

Stratiform clouds.

Question 30

In which environment is aircraft structural ice most likely to have the highest accumulation rate?

Answer 30

Freezing rain.

Question 31

What are characteristics of a moist, unstable air mass?

Answer 31

Turbulence and showery precipitation.

Question 32

What are the characteristics of stable air?

Answer 32

Poor visibility and steady precipitation.

Question 33

During the life cycle of a thunderstorm, which stage is characterized predominately by downdrafts?

Answer 33

Dissipating.

Question 34

Which conditions result in the formation of frost?

Answer 34

The temperature of the collecting surface is at or below the dewpoint of the adjacent air and the dewpoint is below freezing.

Question 35

One weather phenomenon which will always occur when flying across a front is a change in the

Answer 35

wind direction.

Question 36

Thunderstorms reach their greatest intensity during the

Answer 36

mature stage.

Question 37

Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?

Answer 37

Precipitation beginning to fall.

Question 38

Which weather phenomenon is always associated with a thunderstorm?

Answer 38

Lightning.

Question 39

What are characteristics of unstable air?

Answer 39

Turbulence and good surface visibility.

Question 40

What feature is normally associated with the cumulus stage of a thunderstorm?

Answer 40

Continuous updraft.