ATSC 113: MIDTERM EXAM QUESTIONS
WITH COMPLETE SOLUTIONS
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.
Upslope Fog - Answer-When the wind blows air against a hill slope, the air is pushed
upward. But upward-moving air cools adiabatically (without the transfer of heat) about
10°C for each 1 kilometer that it goes up. When the air rises sufficiently high and gets
sufficiently cold, then fog can form.
, Precipitation of Frontal fog - Answer-Precipitation fog or frontal fog is formed by adding
moisture, via the evaporation from warm rain drops falling down through the initially-
unsaturated cooler air below cloud base.
Steam fog - Answer-Steam fog occurs when cold air moves over warm humid surfaces
such as unfrozen lakes or oceans during early winter.
Obscured - Answer-something is totally or partially blocking your view of either the sky
or the ground
Mist
Fog
Smoke
Volcanic Ash
Sand
Haze
Spray
Dust
Snow
Blowing snow
Physiology - Answer-Is how your body, and body parts, work
Hypoxic - Answer-suffering from an insufficient supply of oxygen
Air Density - Answer-is the mass (kg) of air molecules within a volume (cubic meter)
density = mass/velocity
Ideal Gas Law - Answer-The relationship between (density decreases when pressure
decreases or temperature increases)
Pressure Altitude - Answer-The altitude estimated from atmospheric pressure alone
Density Altitude - Answer-The altitude that the aircraft "feels"
Headwind - Answer-A wind directly in your face that slows you down
good because they allow for use of a shorter runway
bad because they slow you down and require that you use more fuel to get to your
destination
Tailwind - Answer-A wind directly behind you
Good because you can go faster allowing you to get your destination soon
WITH COMPLETE SOLUTIONS
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.
Upslope Fog - Answer-When the wind blows air against a hill slope, the air is pushed
upward. But upward-moving air cools adiabatically (without the transfer of heat) about
10°C for each 1 kilometer that it goes up. When the air rises sufficiently high and gets
sufficiently cold, then fog can form.
, Precipitation of Frontal fog - Answer-Precipitation fog or frontal fog is formed by adding
moisture, via the evaporation from warm rain drops falling down through the initially-
unsaturated cooler air below cloud base.
Steam fog - Answer-Steam fog occurs when cold air moves over warm humid surfaces
such as unfrozen lakes or oceans during early winter.
Obscured - Answer-something is totally or partially blocking your view of either the sky
or the ground
Mist
Fog
Smoke
Volcanic Ash
Sand
Haze
Spray
Dust
Snow
Blowing snow
Physiology - Answer-Is how your body, and body parts, work
Hypoxic - Answer-suffering from an insufficient supply of oxygen
Air Density - Answer-is the mass (kg) of air molecules within a volume (cubic meter)
density = mass/velocity
Ideal Gas Law - Answer-The relationship between (density decreases when pressure
decreases or temperature increases)
Pressure Altitude - Answer-The altitude estimated from atmospheric pressure alone
Density Altitude - Answer-The altitude that the aircraft "feels"
Headwind - Answer-A wind directly in your face that slows you down
good because they allow for use of a shorter runway
bad because they slow you down and require that you use more fuel to get to your
destination
Tailwind - Answer-A wind directly behind you
Good because you can go faster allowing you to get your destination soon
