ATSC 113: MIDTERM EXAM QUESTIONS
WITH COMPLETE SOLUTIONS
Pileus - Answer-Form over fast-growing cumulus clouds. Interesting to watch, but they
are harmless, and don't affect flying, sailing or snow sports.
Pyrocumulus - Answer-Form over forest fires and volcanoes. Indicate a forest fire so
strong that the heat and moisture released can make a thunderstorm in the smoke.
Rotor Clouds - Answer-Indicate severe or extreme turbulence at low altitudes due to
mountain waves. The rotors can break off aircraft wings and cause pilots to lose control
of their aircraft during take-off and landing. Can also affect sailors if the rotors occur
over water (lakes or coastal regions) downwind of mountains.
Wind shear - Answer-change of wind speed or direction
Clear air turbulence (CAT) - Answer-moderate to strong bumps
Above Ground level (AGL) - Answer-
Broken - Answer-Refer to graph
Ceiling - Answer-For aviation, the altitude of cloud base for the lowest cloud with
coverage ≥ 5 oktas (i.e. lowest broken or overcast clouds) is considered the ceiling
Cloud Amount - Answer-The fraction of the sky (celestial dome) covered by cloud is
called sky cover, cloud cover, or cloud amount
Cloud Cover - Answer-The fraction of the sky (celestial dome) covered by cloud is
called sky cover, cloud cover, or cloud amount
IFR - Answer-Instrument Flight Rules
mean that you can conduct most of the flight by NOT looking out the window.
METARs - Answer-Meteorological Aviation Reports
Oktas - Answer-Eighths of the sky covered
Overcast - Answer-Refer to graph
Skycover - Answer-The fraction of the sky (celestial dome) covered by cloud is called
sky cover, cloud cover, or cloud amount
, Vertical visibility - Answer-poor visibility at ground level that a ground based weather
observer cannot see whether there are any clouds or not.Ex, fog, forest fire
VFR - Answer-Visual Flight Rules
means that you fly by mostly looking out the window. You need good visibility and need
to stay out of clouds. By looking with your eyes, you can:
WMO - Answer-World Meteorological Organization
CAVOK - Answer-Ceiling and Visibility are OK
Ceiling - Answer-is the height above ground level (AGL) of the lowest cloud base
(bottom of the cloud) that is below 20,000 ft (6,000 m) that is covering MORE than half
the sky (i.e. cloud coverage amount is 5/8 or greater; namely, is either "broken" or
"overcast" —see Learning Goal 1c). Ceilings are reported as a height, e.g. the ceiling is
500 feet above ground level.
Visibility - Answer-Visibility: is a measure of how far away you can see a black object
during daytime, or how far away you can see a bright light at night. It is measured as a
distance.
Transmissometers - Answer-shine an incident light beam across a known path length
and measure how much dimmer the received (Transmitted) light is compared to when
the air is clean.
Runway Visual Range - Answer-Indicates how far ahead a pilot can see horizontally
along a runway centerline.
Fog - Answer-is a cloud that touches the ground, reduces visibility and makes is difficult
to see where you are
Freezing Fog - Answer-Fog is made up of supercooled tiny water droplets
Ice Fog - Answer-Is made up of tiny ice crystals
Radiation Fog - Answer-During clear, nearly-calm nights the ground cools by infra-red
radiation to space. The cold ground cools the air that touches the ground. These fogs
often form first as a very shallow fog, and gradually get thicker (deeper, and lower
visibility) as the night progresses.
Advection fog - Answer-Humid air blows over a colder surface, causing the air
temperature to decrease to the dew-point temperature.
These fogs can form as thick layers, sometimes with sharp, well-defined front edges.
WITH COMPLETE SOLUTIONS
Pileus - Answer-Form over fast-growing cumulus clouds. Interesting to watch, but they
are harmless, and don't affect flying, sailing or snow sports.
Pyrocumulus - Answer-Form over forest fires and volcanoes. Indicate a forest fire so
strong that the heat and moisture released can make a thunderstorm in the smoke.
Rotor Clouds - Answer-Indicate severe or extreme turbulence at low altitudes due to
mountain waves. The rotors can break off aircraft wings and cause pilots to lose control
of their aircraft during take-off and landing. Can also affect sailors if the rotors occur
over water (lakes or coastal regions) downwind of mountains.
Wind shear - Answer-change of wind speed or direction
Clear air turbulence (CAT) - Answer-moderate to strong bumps
Above Ground level (AGL) - Answer-
Broken - Answer-Refer to graph
Ceiling - Answer-For aviation, the altitude of cloud base for the lowest cloud with
coverage ≥ 5 oktas (i.e. lowest broken or overcast clouds) is considered the ceiling
Cloud Amount - Answer-The fraction of the sky (celestial dome) covered by cloud is
called sky cover, cloud cover, or cloud amount
Cloud Cover - Answer-The fraction of the sky (celestial dome) covered by cloud is
called sky cover, cloud cover, or cloud amount
IFR - Answer-Instrument Flight Rules
mean that you can conduct most of the flight by NOT looking out the window.
METARs - Answer-Meteorological Aviation Reports
Oktas - Answer-Eighths of the sky covered
Overcast - Answer-Refer to graph
Skycover - Answer-The fraction of the sky (celestial dome) covered by cloud is called
sky cover, cloud cover, or cloud amount
, Vertical visibility - Answer-poor visibility at ground level that a ground based weather
observer cannot see whether there are any clouds or not.Ex, fog, forest fire
VFR - Answer-Visual Flight Rules
means that you fly by mostly looking out the window. You need good visibility and need
to stay out of clouds. By looking with your eyes, you can:
WMO - Answer-World Meteorological Organization
CAVOK - Answer-Ceiling and Visibility are OK
Ceiling - Answer-is the height above ground level (AGL) of the lowest cloud base
(bottom of the cloud) that is below 20,000 ft (6,000 m) that is covering MORE than half
the sky (i.e. cloud coverage amount is 5/8 or greater; namely, is either "broken" or
"overcast" —see Learning Goal 1c). Ceilings are reported as a height, e.g. the ceiling is
500 feet above ground level.
Visibility - Answer-Visibility: is a measure of how far away you can see a black object
during daytime, or how far away you can see a bright light at night. It is measured as a
distance.
Transmissometers - Answer-shine an incident light beam across a known path length
and measure how much dimmer the received (Transmitted) light is compared to when
the air is clean.
Runway Visual Range - Answer-Indicates how far ahead a pilot can see horizontally
along a runway centerline.
Fog - Answer-is a cloud that touches the ground, reduces visibility and makes is difficult
to see where you are
Freezing Fog - Answer-Fog is made up of supercooled tiny water droplets
Ice Fog - Answer-Is made up of tiny ice crystals
Radiation Fog - Answer-During clear, nearly-calm nights the ground cools by infra-red
radiation to space. The cold ground cools the air that touches the ground. These fogs
often form first as a very shallow fog, and gradually get thicker (deeper, and lower
visibility) as the night progresses.
Advection fog - Answer-Humid air blows over a colder surface, causing the air
temperature to decrease to the dew-point temperature.
These fogs can form as thick layers, sometimes with sharp, well-defined front edges.
