Icing

Question 1

Ice accretion directly affects aircraft performance because of…

Answer 1

Decrease lift, increased drag

Question 2

Very high liquid water content in cloud tends to give (assume below 0)

Answer 2

Severe clear icing

Question 3

Name 2 situations where strong lift may result in high liquid water content

Answer 3

1) Layered clouds with a strong lift as in fronts

2) In situation where there’s a strong lift rapidly converting vapor to droplets

Question 4

At what range of temperature are the largest drop sizes most abundant?

Answer 4

0@-10

Question 5

What combination will most likely give clear icing (all temp below 0)

Answer 5

Large drops & warm temperature

Question 6

Most icing occurs between____and____, most severe icing occurs between ____and____, a reduced icing risks occurs between ____and___, and all water droplets are frozen at colder than____

Answer 6

0 & -15
0 & -10
-15 & -40
-40

Question 7

Describe Rime icing

Answer 7

Quick freeze, crusty ice, like hard snow, builds forward, easy to remove

Question 8

Describe clear icing

Answer 8

Hard, glassy surface, spreads back, difficult to remove

Question 9

Describe hoar frost

Answer 9

White, feathery, crystalline

Question 10

The icing intensity which requires continuous de-icing or diversion is…

Answer 10

Moderate

Question 11

Describe the icing and intensity if applicable for the following clouds or precipitation:
NS
CB
TCU
ACC
FZDZ
FZRA
Thick ST
AS

Answer 11

NS: Rime icing
CB: Severe clear ice
TCU: Clear, moderate to severe
ACC: Clear, moderate to severe
FZDZ: Clear, light to moderate
FZRA: clear, severe
Thick ST: clear, light to moderate
AS: rime

Question 12

The collection rate of super cooled droplets is more efficient for…

Answer 12

Narrow, fast moving airfoil