Aircraft icing

Question 1

Three main types of Airframe icing:

Answer 1

Rime ice
Clear, ice
Mixed ice

Question 2

Rime ice

Answer 2

This is formed by the instantaneous freezing of small, super cold water. Droplets skin temperature must be less than 0°C.
Forms in layer – type of clouds, such a stratus. Not very adhesive, and Bridal. Most commonly resulting in light to moderate levels of icing.

Question 3

Clear, ice

Answer 3

Formed when large, super cold water, droplets slowly freeze to the aircraft skin skin temperature, less than 0°C. Smooth and transparent. The most dangerous type of icing!

Larger accumulations are characterized by the presence of upper and lower horns

Question 4

Mixed ice

Answer 4

This is a combination of rime and clear ice

Question 5

What three things have an effect on the rate of ice accumulation?

Answer 5

Airfoil shape
Airfoil size
Droplet size

Question 6

What type of aerofoil shape collects ice quicker

Answer 6

A thin airfoil collects ice, more efficiently than a thick one

Question 7

Does the speed of an aircraft affect the accumulation of ice?

Answer 7

Yes, the higher airspeed the greater rates of accumulation

Question 8

Does droplet size affect the ice accumulation on an airplane?

Answer 8

Large droplets, require strong, vertical currents to overcome gravity, so vertically developed clouds, what has larger droplets. A larger water drop that will be more likely to strike the wing and a smaller droplet clouds with larger liquid contact will have a greater icing intensity. This means that clouds and warmer air masses are more suspect.

Question 9

Four types of icing intensity

Answer 9

Trace
Light
Moderate
Severe

Question 10

Trace icing

Answer 10

It is not hazardous, even without the icing or anti-icing equipment, unless it is encounter for an extended period of time more than one hour

Question 11

White icing

Answer 11

In this environment, the rate of accumulation may create a problem if the flight is prolonged over one hour

Question 12

Moderate icing

Answer 12

In moderate icing conditions, the rate of accumulation is quick enough, that even short encounters will be potentially hazardous

Question 13

Severe icing

Answer 13

The rate of accumulation is fast enough to render deicing or anti-icing equipment useless. An immediate diversion is necessary.

Question 14

What should I do when I encounter icing

Answer 14

Make an immediate decision. Climb or descend, or go back.

Question 15

What are some effects of aircraft icing?

Answer 15

Overall, the Aircraft-Performance will decrease. There will be an increase in drag, which requires more power to sustain flight. A decrease in power available from the intake blockage. Engine failure due to car pricing for blocking of the air and take.

Question 16

More effects of aircraft icing

Answer 16

Icing alters the shape of the wing, which will cause an increase in stall speed. The angle of attack at which the stall occurs is decreasing, which means the stall speed is increasing.

Question 17

How does frost effect an aircraft?

Answer 17

Frost disrupts the air flow over the wing, thereby increasing the stall speed. When lift is reduced by 30% and drag is increased by 40%.

Question 18

What are the critical surfaces on an airplane?

Answer 18

Wings
Control surfaces
Rotors/propellers
Horizontal stabilizer’s/vertical stabilizer’s
Upper surface of fuselage in the rear mounted engine
Any other stabilizing surface of an aircraft

Question 19

Aircraft icing – CARS

Answer 19

No person may attempt to contact to takeoff in any aircraft that has frost, ice, or snow, adhering to any of its critical surfaces