3-33.
Postfrontal fog may be formed under
which of the following conditions?
1.
Two air masses are near
saturation and accompanied by
light winds
2.
The postfrontal air mass is
temporarily heated from below
3. Hydrocarbon fuels are present
with a quasi-stationary frontal
system
4.
A quasi-stationary east-west
oriented cold front is present
and the continental polar air
behind the front is stable
3-34.
Frontal passage fog may form where
associated air masses are near
saturation,
with light frontal
winds.
1.
True
2.
False
3-35.
Sea fogs tend to dissipate under
which of the following conditions?
1.
When the winds are greater than
6 knots
2.
When the underlying water
continually becomes colder
3.
When there is radiational
cooling from the warm water
4.
When the sea fog flows over
warm land
3-36.
Assume that a sounding is taken at
a time when stratus clouds are
observed over your location.
Which
of the following conditions will
usually exist near the surface?
1.
A moist adiabatic lapse rate
2.
A dry adiabatic lapse rate
3. A shallow convective cloud deck
4.
A temperature inversion
3-37.
You are using the dry adiabatic
method to predict the height of the
top of a layer of fog.
The average
mixing ratio line intersects the
temperature curve at 20°C, and the
dry adiabat of this intersection
reaches the surface level at a
temperature of 30°C.
The top of
this layer of fog will be at what
height?
1.
1,000 ft
2.
1,640 ft
3.
3,280 ft
4.
5,280 ft
3-38.
The “critical temperature” is the
surface temperature at which fog
will
1.
form, provided no changes have
taken place in the sounding
2.
dissipater regardless of
changes in the sounding
3.
dissipate,
provided no changes
have taken place in the
sounding
4.
form,
regardless of changes in
the sounding
3-39.
A stratus layer is over your
station when you take a morning
sounding at 0600 local standard
time, with a surface temperature of
8.5°C.
The surface temperature at
which dissipation will begin is
computed to be 16°C, with
dissipation to be complete when the
temperature reaches 24°C. If
heating is forecast to increase at
the rate of 4°C per hour for the
first 2 hours, and 6°C per hour for
the next 3 hours, at what time
should you forecast the stratus
layer to dissipate?
1.
0915 local standard time
2.
0945 local standard time
3.
1015 local standard time
4.
1045 local standard time
3-40.
What causes a supercooled water
droplet to freeze on contact with
an aircraft at -3°C when it will
not normally freeze until the
temperature is between -10°C and
-40°C?
1.
The internal stability of the
droplet is destroyed when it
strikes the aircraft, and its
freezing point is raised
2.
The surrounding air temperature
is below 0°C, causing the water
droplets to freeze immediately
3. The airflow created by the
engine creates sufficient
disturbance to destroy the
stability of the water droplets
4.
Supercooled water droplets
normally freeze at -3°C
3-41.
In the course of a flight from
takeoff to landing, at what stage
is a turbojet aircraft LEAST
susceptible to icing?
1.
When in the landing pattern
2.
When taking off
3.
When in final approach
4.
At cruising altitude and speed
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