Icing

Question 1

What are 4 effects of icing

Answer 1

1. Increase in weight
2. Alters CoG
3. Increased drag
4. Vibrations

REMEMBER: Increased Weight and Drag Can Vibrate

Question 2

What are 4 risks of icing
1. ?? of p??
2. ?? of a i??
3. ?? visibility
4. ?? of a?? L??

Answer 2

1. Blockage of ports
2. Blockage of air intakes
3. Reduced visibility
4. Loss of aerodynamic lift

P I V L
Ports Intakes Visibility Lift

Question 3

The worst icing occurs in what temperature range

Answer 3

0℃ to -12℃

Question 4

Where does icing generally occur

Answer 4

Cloud less than 0℃

Question 5

What is super cooled water droplets

Answer 5

Water cooled below freezing (liquid state still)
Unable to form to ice as no particle exists to trigger transition from liquid to solid

Question 6

What are the 4 classifications of icing
i.e. ____ icing

Answer 6

1. Trace
2. Light
3. Moderate
4. Servere

Question 7

What type of icing is defined below

Ice becomes perceptible. Rate of accumulation of ice is slightly greater than the rate of loss. Not hazardous unless encountered for more than one hour

Answer 7

TRACE

Question 8

What type of icing is defined below

Rate of accumulation may create a problem for flight in this environment for one hour. Unless encountered for one hour or more, de-icing/anti-icing equipment and/or heading or altitude change not required. Occasional use of de-icing equipment removes ice

Answer 8

LIGHT

Question 9

What type of icing is defined below

The rate of accumulation is such that even short encounters become potentially hazardous. De-icing/anti-icing require to remove/prevent accumulation or heading or altitude change or diversion required.

Answer 9

MODERATE

Question 10

What type of icing is defined below

The rate of accumulation is such that de-icing / anti-icing equipment fails to reduce or control the hazard. De-icing / anti-icing plus immediate heading or altitude change or diversion required

Answer 10

SEVERE

Question 11

Which 2 cloud types pose the biggest risk of icing

Answer 11

1. Cumulus
2. Orographically formed

Question 12

What are the in-flight icing formation risk temperature ranges;

HIGH RISK;
1.Cumulus Clouds
2.Stratiform Clouds
3.Rain and Drizzle

Answer 12

1. 0℃ to -20℃
2. 0℃ to -15℃
3. 0℃ and below

Question 13

What are the in-flight icing formation risk temperature ranges;

MEDIUM RISK;
1. Cumulus Clouds
2. Stratiform Clouds

Answer 13

1. -20℃ to -40℃
2. -15℃ to -30℃

Question 14

What are the in-flight icing formation risk temperature ranges

LOW RISK;
1. Cumulus Clouds
2. Stratiform Clouds

Answer 14

1. < than -40℃
2. < than -30℃

Question 15

What type of icing is defined below;

• Formed from water droplets impacting airframe
• Brittle
• Semi opaque (trapped air)

Answer 15

RIME ICE

Question 16

What type of icing is defined below;

• Formed as water droplets flow backwards along airframe
• Dense weight
• Difficult to remove
• Creep to parts of airframe not protected by anti-icing measures

Answer 16

CLEAR ICE

Question 17

What type of icing is defined below;

• Found on cold mornings on structures at ground level
• Formed by sublimation
• Dramatically affects aerodynamics

Answer 17

HOAR FROST

Question 18

What type of icing is defined below;

• Rain falling from cloud descends into colder air
• Very difficult to remove
• Associated with warm fronts

Answer 18

RAIN ICE
(Freezing rain)

Question 19

What are the 4 key factors causing carburettor ice

Answer 19

1. PRESSURE
2. TEMPERATURE
3. WATER VAPOUR
4. VENTURI EFFECT

1. Reduced pressure in venturi
2. Reduced dew point
3. Condensing of water vapour
4. Temperature drop in venturi (fuel evaporating takes heat energy from the atmopshere)

Question 20

What is the approximate temperature drop insite a carburettor venturi

Answer 20

25℃ to 30℃

Question 21

What are the 3 affects of carb icing
1. Ice forms where?
2. There is less what in the engine?
3. The throttle is what?

Answer 21

1. Ice forms in venturi
2. Less volume of fuel/air mixture to engine
3. Throttle immoveable

Question 22

Carb icing is more likely on COLD or WARM days

Answer 22

WARM DAYS

Question 23

What is the dominant factor of carb icing

Answer 23

HUMIDITY

Question 24

What are the 4 key symptoms of carb icing

What you are the pilot might experience in the plane to understand it is suffering from icing

Answer 24

1. Decrease in RPM
2. Decrease in manifold pressure
3. Rough running engine
4. Eventual engine failure

Question 25

What feature is used to melt ice in the carburettor

Answer 25

CARB HEAT

Question 26

How does a carb heat control work

Answer 26

WARM AIR Selects different source of intake air

Question 27

Why will an engine under perform when using carb heat

Answer 27

WARM AIR LESS DENSE Engine performance is impacted

Question 28

In a situation where the engine is running roughly and carb icing is assumed to be the cause, one application of carb heat, what may happen

Answer 28

Engine runs even more roughly ## Footnote Ice melts, water mixes with fuel and air Warm air is more dense Both features will cause rougher running engine

Question 29

What are 2 key reasons why an engine runs rougher when carb is applied

Answer 29

1. Ice melting turns to water, which mixes with fuel and air 2. Warm air more dense, less air in mixture (less effective)

Question 30

Which engine type does not have a carb heat control

Answer 30

FUEL INJECTION ENGINES ## Footnote Do not have carburettors

Question 31

What are 4 actions a pilot can take against icing

Answer 31

1. Apply carb/pitot heat 2. Descend to warmer air 3. Increase airspeed 4. Increase propeller RPM