ATSC 113 Fly C Exam Questions with
Correct Answers
characteristics of stratiform or layer clouds - Answer-associated with atmospheric layers
of different relative temperatures (happy cake)
typical of warm fronts
See corona: bright circle with colourful fringes from the diffraction of sunlight in water
droplets of the cloud
types of stratiform clouds - Answer-high (cirrus, cirrostratus, and cirrocumulus), middle
(altostratus, and altocumulus), low (stratus = well defined cloud bases, and
nimbostratus = diffused cloud bases & precipitation)
stratocumulus clouds - Answer-low layer of lumpy clouds; characteristics of both
cumuliform and stratiform clouds
fog characteristics - Answer-cloud that touches ground with poor visibility (less than 1
km); most likely during late night and early morning
formed in 2 ways: 1) water added to unsaturated air, or 2) unsaturated air cooled to
dew-point temperature (point where water begins to condense)
+ wind = turbulence mixes cool humid air with warm dry air, which dissipates fog
+ clear skies = ground radiates heat and becomes cold, if air cooled by ground is humid
and cooled enough becomes fog
+ cloud cover = clouds preventing ground cooling, prevents fog
freezing fog - Answer-fog made of supercooled water droplets
ice fog - Answer-fog made of tiny ice crystals
Valley fog forms when... - Answer-Cool, dense air flows downhill and settles in a valley
fog type - radiation - Answer-ground cools by infra-red radiation, cooling the air above it
fogs that form are shallow and gradually get thicker as night progresses
if fog becomes deep enough, IR cooling happens from fog top = fog becomes hard to
dissipate
fog type - advection - Answer-humid air blown over colder surface
forms a thick layer with sharp, defined front edges
fog type - upslope - Answer-air pushed uphill cools adiabatically at 10°C/1km up
appear as if the mountain top is in a cloud
, fog type - precipitation/frontal - Answer-formed by adding moisture via evaporation from
warm rain drops falling down into unsaturated cooler air (rain into cooler clouds,
waterfall droplets/spray)
also creates fractus clouds
fog type - steam - Answer-occurs when cold air moves over warm humid surfaces (air
warmed through conduction, water aded by evaporation)
warm air rises, creating a layer of convective turbulence touching the ground
turbulence causes humid air to mix with colder air higher up, creating steam fog
fog as an obscuration - Answer-fog reduces horizontal visibility to 0.5 statute miles or
less
"socked in" - trapped at an airport because of fog
fog will dissipate/lift from sunlight warming the earth, or winds picking up/turbulence
sky cover, cloud cover, or cloud amount - Answer-fraction of the sky (celestial dome)
covered by clouds; measured in 8ths (oktas)
NEVER underestimate, always assume a cloud is hiding another cloud above it
sky cover by oktas - Answer-0: clear
1-2: few
3-4: scattered
5-7: broken
8: overcast
9: sky obscured
ceiling characteristics - Answer-the altitude of cloud base for the lowest cloud with
coverage of 5 or more (broken or overcast) oktas and below 20'000ft (6'000m)
if obscured, the vertical visibility distance is reported as the ceiling
ceilings are measured with... - Answer--traditional ceilometers (uses trig)
- laser ceilometers (light burst, time to reflect back)
-ceiling balloons
- pilot reports
- weather-observer estimates (worst)
CAVOK - Answer-Ceiling and Visibility OK
min. requirements for VFR flight - Answer--horizontal visibility of 3 statute miles or more,
AND
-ceiling of 1000 ft above the airport
Marginal VFR - Answer-conditions which VFR is allowed, but visibility is poor and/or
cloud-base is low
Correct Answers
characteristics of stratiform or layer clouds - Answer-associated with atmospheric layers
of different relative temperatures (happy cake)
typical of warm fronts
See corona: bright circle with colourful fringes from the diffraction of sunlight in water
droplets of the cloud
types of stratiform clouds - Answer-high (cirrus, cirrostratus, and cirrocumulus), middle
(altostratus, and altocumulus), low (stratus = well defined cloud bases, and
nimbostratus = diffused cloud bases & precipitation)
stratocumulus clouds - Answer-low layer of lumpy clouds; characteristics of both
cumuliform and stratiform clouds
fog characteristics - Answer-cloud that touches ground with poor visibility (less than 1
km); most likely during late night and early morning
formed in 2 ways: 1) water added to unsaturated air, or 2) unsaturated air cooled to
dew-point temperature (point where water begins to condense)
+ wind = turbulence mixes cool humid air with warm dry air, which dissipates fog
+ clear skies = ground radiates heat and becomes cold, if air cooled by ground is humid
and cooled enough becomes fog
+ cloud cover = clouds preventing ground cooling, prevents fog
freezing fog - Answer-fog made of supercooled water droplets
ice fog - Answer-fog made of tiny ice crystals
Valley fog forms when... - Answer-Cool, dense air flows downhill and settles in a valley
fog type - radiation - Answer-ground cools by infra-red radiation, cooling the air above it
fogs that form are shallow and gradually get thicker as night progresses
if fog becomes deep enough, IR cooling happens from fog top = fog becomes hard to
dissipate
fog type - advection - Answer-humid air blown over colder surface
forms a thick layer with sharp, defined front edges
fog type - upslope - Answer-air pushed uphill cools adiabatically at 10°C/1km up
appear as if the mountain top is in a cloud
, fog type - precipitation/frontal - Answer-formed by adding moisture via evaporation from
warm rain drops falling down into unsaturated cooler air (rain into cooler clouds,
waterfall droplets/spray)
also creates fractus clouds
fog type - steam - Answer-occurs when cold air moves over warm humid surfaces (air
warmed through conduction, water aded by evaporation)
warm air rises, creating a layer of convective turbulence touching the ground
turbulence causes humid air to mix with colder air higher up, creating steam fog
fog as an obscuration - Answer-fog reduces horizontal visibility to 0.5 statute miles or
less
"socked in" - trapped at an airport because of fog
fog will dissipate/lift from sunlight warming the earth, or winds picking up/turbulence
sky cover, cloud cover, or cloud amount - Answer-fraction of the sky (celestial dome)
covered by clouds; measured in 8ths (oktas)
NEVER underestimate, always assume a cloud is hiding another cloud above it
sky cover by oktas - Answer-0: clear
1-2: few
3-4: scattered
5-7: broken
8: overcast
9: sky obscured
ceiling characteristics - Answer-the altitude of cloud base for the lowest cloud with
coverage of 5 or more (broken or overcast) oktas and below 20'000ft (6'000m)
if obscured, the vertical visibility distance is reported as the ceiling
ceilings are measured with... - Answer--traditional ceilometers (uses trig)
- laser ceilometers (light burst, time to reflect back)
-ceiling balloons
- pilot reports
- weather-observer estimates (worst)
CAVOK - Answer-Ceiling and Visibility OK
min. requirements for VFR flight - Answer--horizontal visibility of 3 statute miles or more,
AND
-ceiling of 1000 ft above the airport
Marginal VFR - Answer-conditions which VFR is allowed, but visibility is poor and/or
cloud-base is low
