Effects of Weather on UAS

Question 1

What should an airman be able to demonstrate knowledge of?

Answer 1

Weather effects on sUAS performance

Question 2

What is the minimum visibility for flying?

Answer 2

At a minimum sUAS pilots must have 3 SM of visibility 500 feet below the clouds

Question 3

Define Density Altitude

Answer 3

the density of the air given as a height above MSL
and is an interpretation of how an aircraft will feel, performance-wise,
at a certain altitude

Question 4

Define Indicated altitude

Answer 4

Altitude: the height displayed on your altimeter

Question 5

Define Pressure Altitude

Answer 5

Pressure Altitude: the altitude indicated with the barometric pressure
is set to 29.92 inches of mercury (inHg)

Question 6

What happens with high density altitude

Answer 6

There is thinner air and a reduced aircraft performance

Question 7

____ occurs at lower elevations, higher atmospheric presure and lower temperature and/or lower humidity

Answer 7

Low density altitude

Question 8

Does low density altitude have thin or thick air?

Answer 8

Thicker air

Question 9

What is the aircraft performance in low density altitude

Answer 9

Better aircraft performance

Question 10

What do tree do to the air?

Answer 10

Trees and water can cause cooling and sinking air

Question 11

What type of air do crop land bare earth and paved surfaces have?

Answer 11

Crop land, bare earth and paved surfaces can cause warm rising air

Question 12

What are the winds like on east side of cascades?

Answer 12

More violent, have katabatic winds, turbulent

Question 13

What is the wind like in Urban areas?

Answer 13

Effects similar to katabatic winds. Rotating wind, spinning on the corners of buildings.

Question 14

How is GPS in urban area

Answer 14

HORRIBLE!

Question 15

Cool, dry air is _____ and leads to what time of weather?

Answer 15

Cool, dry air is very stable and leads to good,

clear weather

Question 16

What type of air is generally Unstable?

Answer 16

Warm moist air is generally unstable, the more

so, the greater the instability

Question 17

What type of clouds produce thunderstorms?

Answer 17

Cumulonimbus clouds produce thunderstorms when sufficient water vapor,
unstable lapse rate and updrafts of warm air are present that prevent moisture
from falling until the top of the cloud formation is high enough in the atmosphere
that it can no longer hold moisture

Question 18

What is wind shear?

Answer 18

Wind shear refers to a change in wind speed or direction with height in
the atmosphere

Wind shear can also refer to a rapid change in winds over a short horizontal
distance experienced by aircraft, conditions that can cause a rapid change in
lift, and thus the altitude, of the aircraft

Question 19

Microburst defined?

Answer 19

A microburst is a localized column of sinking air (downdraft) within a
thunderstorm and is usually less than or equal to 2.5 miles in diameter

Question 20

What can microburst produce?

Answer 20

Can produce severe downdrafts that can exceed 80 MPH

Can produce hazardous wind change direction in a matter of seconds

Effects are not limited purely to the localized column and can extend outward many
miles

Question 21

Temperature Inversions

Answer 21

Warm air comes on top of cool air and cool air is trapped.

Pollution is trapped in cold air

Question 22

Inversion do what to VLOS

Answer 22

make it harder to see, reduce VLOS

Question 23

The amount of moisture present in atmosphere is dependent on?

Answer 23

The air temperture

Question 24

Ever 20 degrees F increase in temperature does what to air moisture?

Answer 24

Doubles the moisture the air can hold

Question 25

What are two ways to add water vapor to the atmosphere?

Answer 25

Evaporation – change from liquid water to water vapor

Sublimation – change of ice directly to water vapor

Question 26

What is humidity?

Answer 26

Humidity is the amount of water vapor
present in the atmosphere at any given
time

Question 27

What is RH?

Answer 27

Relative Humidity (RH) is the amount of
moisture in the air compared to the amount of
moisture the air can actually hold at that
temperature

Question 28

What is dew point?

Answer 28

The dew point is the temperature at which air
can no longer hold moisture

When temperature and the dew point meet,
fog formation is likely

Question 29

What is Precipitation Static

Answer 29

P-Static is a form of radio interference caused by rain, snow or dust
particles hitting the sUAS antennas and inducing a small
radio-frequency voltage into it

Question 30

What are the five kinds of fog?

Answer 30

Raditation 
Advection
Upslope
Steam 
Ice

Question 31

What is Radiation Fog?

Answer 31

Radiation fog – forms on clear, calm nights in low-lying areas when the ground cools rapidly
and the surrounding air reaches its dewpoint

Question 32

What is Advection fog?

Answer 32

Advection fog – forms when wind/sea breezes blow warm moist air over cooler land masses,
can persist for days and usually lifts during the day to form low stratus clouds

Question 33

What is Upslope fog?

Answer 33

Upslope fog – forms when wind/land breezes blow moist stable air up the slope of a mountain
and can persist for days

Question 34

What is Steam fog?

Answer 34

Steam fog – common over water bodies during cold times of the year, forms when cold dry air
moves over warmer water, looks like smoke (like when you take a hat off in cold weather and
your head creates steam) and can cause icing

Question 35

What is ice fog?

Answer 35

Ice Fog – needs VERY cold temperatures to occur, and occurs in low lying areas; water vapor
forms directly into ice crystals