clouds and conditions that produce icing + carburetor icing

What are the 2 requirements for ice to form on an aircraft while in flight?

Must be flying through visible water, and the water droplets or surface temperature must be 0°C or below

To produce ice, aircraft must be flying through visible water in the form of ____ or ____

rain, cloud droplets

Supercooled water droplets can exist in liquid state in temperatures as low as _____. However, they are very ____ and when disturbed, will _____ change into ice.

-40°C, unstable, rapidly

Clouds formed at temperatures ______ are usually composed of ______.

below -20°C, ice crystals

The heaviest icing usually occurs in the range of _____ when supercooled water droplets freeze on impact and adhere to the plane.

-10°C and 0°C

Serious icing is encountered in what type of clouds?

Cumuliform clouds

Serious icing is encountered in clouds forming in _____ air along _____.

rising air, a mountain slope or frontal surface

Which cloud types produce the heaviest icing potential?

CU, TCU, and CB

However, in winter, _____ clouds produce the most frequent conditions.

stratocumulus (SC) clouds

The most dangerous types of icing are encountered in dense clouds composed of heavy accumulations of ______ and in _____.

large supercooled water droplets, freezing rain

____, ____ clouds are composed of ice crystals; these crystals _____ to aircraft

High, cirrus-type, do not adhere

The ____ the cloud, the greater the icing potential

thicker

Carburetor icing is especially treacherous because it can form in clear air when _____ is high and outside air temperature (OAT) are ________

humidity, well above freezing

Carburetor icing only forms when outside air temperature is below freezing

False

The ___ of fuel, combined with the _____ of air as it passes through the carburetor, can cause a sudden cooling of the mixture

vaporization, expansion

The temperature of air passing through the carburetor may drop as much as _____ within a _____

15°C, fraction of a second

The cooling within a carburetor ______ and, if the temperature in the carburetor reaches 0°C or below, the moisture is deposited as _____ within the carburetor passage.

condenses water vapour, frost or ice

On dry days, or when the temperature is well below freezing, the moisture in the air is sufficient to cause carburetor icing

False

If the temperature is between approximately ______, with _______, carburetor ice is a very real danger

-6°C and -21°, visible moisture or high humidity