1. Visibility & Ice Accretion4 3 . 1
Visibility & Ice Accretion
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2. Restrictions to Visibility
Cloud
Precipitation
Fog
Haze
Smoke
Blowing Snow
Blowing Dust
Blowing Sand
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3. Visibility in Relation to Stability
Stable Air
Impurities are trapped in the lower levels
Drizzle
Fog
Unstable Air
May cause blowing snow, sand or dust
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4. Visibility Terms Visibility Flight Visibility
the distance at which prominent objects may be seen and identified by day and prominent lighted objects by night.
Flight Visibility
range of visibility forward from the cockpit of an aircraft
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5. Visibility Terms Slant Range Visibility Ground Visibility
the distance a pilot can see over the nose of an aircraft towards the ground.
Ground Visibility
the visibility at an airport as reported by an accredited observer. Generally considered as visibility at eye level.
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6. Visibility Terms Prevailing Visibility Runway Visual Range
the distance at which objects of known distance are visible over at least half of the horizon.
Runway Visual Range
a mechanical devise measuring changes in light intensity to estimate the visibility near the touch down point or mid point of a runway.
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7. NOTE: You must use the buttons in the Confirmation Stage

8. Meteorology Visibility & Ice Accretion
Let's try a few review questions on Meteorology:
Question #1 - The visibility at an airport as reported by an accredited observer is known as A
Ground Visibility B
Flight Visibility C
Prevailing Visibility
Slant Range Visibility D
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12. Flying Scholarship Program
That answer is correct.
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13. Meteorology Visibility & Ice Accretion
Let's try a few review questions on Meteorology:
Question #2 - The distance a pilot can see over the nose of the airplane towards the ground is known as A
Ground Visibility B
Flight Visibility C
Prevailing Visibility
Slant Range Visibility D
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17. Flying Scholarship Program
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18. Icing
In temperatures at or below freezing, supercooled water droplets may strike your aircraft and freeze. This is known as icing. Dangerous icing can occur in clouds, freezing rain, or freezing drizzle.
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19. Types of icing Hoar Frost
a white, feathery, crystalline formation that covers the entire surface of the aircraft.
forms by sublimation on cold clear nights
must be removed before take-off since it can increase stall speed and reduce lift
can form in clear air when a cold aircraft enters warmer, damper air during a steep descent
may obscure vision by coating the windshield
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20. Types of icing Frozen Dew
sometimes dew will form on an aircraft parked outside at night. If the aircraft skin temperature falls below freezing this dew will freeze
must be removed before take-off
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21. Types of icing
Rime Ice
an opaque or milky white ice that forms on an a/c
forms by the almost instantaneous freezing of small supercooled water droplets
has no great weight
alters the aerodynamics of the airfoils
chokes off the orifices of the carburetor and the instruments
is very brittle and easily dislodged by de-icing equipment
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22. Types of icing Clear Ice a coating of glass like ice
forms as large supercooled water droplets freeze slowly and spread.
can form a strong, solid sheet of ice which is difficult to dislodge
can increase drag by as much as 300% to 500%
increases the weight of the aircraft
disrupts the smooth airflow over the wings and the tail surfaces decreasing lift
unequal loading may cause vibrations
as large blocks break off, the structure of the aircraft may be impaired
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23. Protection From Icing Fluids Rubber Boots Heating Devices
Released on leading edge to flow over the blades of propellers and wing surfaces.
Rubber Boots
Membranes of rubber attached to the leading edges. They can be made to pulsate in such a way that ice is cracked and broken off after it has already formed.
Heating Devices
Heating vulnerable areas with hot air from the engine or special heaters is a method of preventing the buildup of ice.
Regional Gliding School

24. NOTE: You must use the buttons in the Confirmation Stage

25. An opaque, or milky white ice
Meteorology
Visibility & Ice Accretion
Let's try a few review questions on Meteorology:
Question #3 - Match
An opaque, or milky white ice
A white, feathery, crystalline formation that covers the entire surface of an aircraft A
Hoar Frost B
Rime Ice A
Hoar Frost B
Rime Ice
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28. Flying Scholarship Program
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29. Flying Scholarship Program
That answer is correct.
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30. Meteorology Visibility & Ice Accretion Congratulations!!
You have now completed the Visibility & Ice Accretion lesson of the Meteorology Module. Of course, this lesson is always available to you for future reference if required.
You are now ready to move along to the next Meteorology lesson you have not completed or to any other module you wish. You can advance to the Self Test Module if you feel ready to challenge the final exam.
Good Luck!
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