ATPL ICING

Question 1

Define deposition

Answer 1

Water vapour to ice without water droplets forming, latent heat is released warming atmosphere.

Increases instability

Question 2

Define sublimation

Answer 2

Ice to water vapour

Latent heat absorbed, cools atmosphere increases stability

Question 3

Explain what happens when an aircraft Collides with SCWD (ATPL)

Answer 3

Aircraft is ice nuclei, will form ice on contact with leading edge, rest will flow back and cool
on the airframe.
Aircraft doesn’t need to be below 0°C for icing
Rime ice forms when temps are colder than about - 20°C
Clear ice forms between 0 - -20°C

Question 4

Describe the freezing rain process (ATPL)

Answer 4

Only occurs in warm fronts where warm rain falls into air below 0°C same as CPL.

Question 5

State areas of the globe where freezing rain is most likely to be encountered

Answer 5

Can happen in maritime and continental climates, most common in polar climates

Question 6

Identify the symbols used to indicate different types of icing

Answer 6

Light - no symbol
Moderate - 2 lines
Severe - 3 lines