midterm Flashcards
100
Aircraft turbulence is
irregular motion of air in flight
The first rule in flying through turbulence is to
Fly V(a)
The main natural causes of turbulence are:
convective
mechanical turbulence
wind shear
An additional cause of turbulence, found behind and below aircraft producing lift is
wake turbulence
What should you do if you suspect turbulence is present during an approach?
slightly fast
To avoid turbulence in cumulus clouds you should fly above / through / below the clouds.
Above
Turbulence encountered outside of clouds is called
clear air turbulence
What do “rotor” clouds indicate?
Indicate severe or extreme turbulence at low altitudes due to mountain waves.
T / F To avoid mountain wave turbulence, wait to climb until just before reaching the mountain.
F
. Mountains should be over flown by a clearing altitude of
3000,5000
T / F Another way to avoid mountain wave turbulence is to fly under it through mountain passes.
T
. T / F Mountain valleys may be insulated from peak level winds, so plan accordingly when taking off from a
valley.
T
List 2 things you should be prepared for if you suspect wind shear due to a low-level temperature inversion.
wind shift
wind shear turbulence
Wake turbulence is caused by
lift
List the 3 directions in which wake turbulence moves:
down
out
direction of the wind
How long should you wait for wake turbulence to clear?
5 min
The cumulative effects of icing on the “four forces” are:
a. Lift
b. Drag
c. Weight
d. Thrust
reduced
increased
increased
reduced
Name the 3 types (locations) of icing that can affect the overall performance and systems of an aircraft:
induction icing
structural icing
instrument icing
Two conditions that must be present for structural icing in flight are ____ and
______.
visible moisture
freezing temps
Three types of structural icing are:
Rime
clear
mix
The type of ice that forms when water drops are large, as in cumuliform clouds, is _____________ ice. This
ice is hard and heavy.
clear
The main impact of rime ice is
reduces lift and increases drag
How does induction icing reduce thrust?
clogs up air intakes
List 4 instruments or aircraft systems that may be affected by “instrument icing.”
Radio
Air speed indicator
altimeter
vertical speed indicator
T / F Only cumulus clouds have icing potential
F
Frost forms near the surface primarily in what type of weather conditions?
clear stable air
It takes a _________ amount frost on an aircraft wings to prevent the aircraft from becoming airborne.
small
. What should you do if your aircraft does not have anti-icing or de-icing systems?
avoid icing
To get out of an icing layer, you should change altitude slowly / rapidly to minimize icing potential
Rapidly
If you encounter freezing rain, you should climb / descend to get out of it
climb
T / F If you have a buildup of structural icing, you should maneuver the aircraft to try and break it off.
F
If you are iced up on approach, fly the approach with ____
more power
The three conditions required for thunderstorm formation are:
unstable air
moisture
kick start
The three stages of a thunderstorm cell’s life cycle are:
Cumulus
mature
disapating
The key feature of the first stage of a thunderstorm cell’s life cycle is ________
lift
T / F Since the growth rate of the cloud in its first stage is relatively low (sometimes only 3000 fpm),
a climb to cross over the cloud is one recommended technique to avoid its turbulence.
F
How would a pilot know that a thunderstorm cell was mature?
Precipitation
Updrafts in a thunderstorm can reach a rate of _______during the ________
stage.
6000 fpm
mature
T / F A pilot approaching a squall line should plan to very carefully avoid individual cells by flying
between the well-defined cells at VA .
F
Name the two types of thunderstorms with regard to how they receive their energy.
Air mass
steady state
Why does a steady state thunderstorm last so much longer than an air mass thunderstorm?
being fed
Where does the precipitation fall from a steady state thunderstorm?
outside the cloud
List five hazards thunderstorms present to aircraft in flight.
Squall line low visibility lightning tornado microburst
The more frequent the lightning, _____
worse the storm
Frequent flashes playing along a large sector of the horizon suggests a ___
Squall line
Hazardous turbulence is present in___ thunderstorms.
All
If caught in the turbulence of a thunderstorm, a pilot should try and maintain constant
_______________ to minimize stress on the aircraft.
Attitude
Hail has been observed
In clear air miles away from storm
T / F Rain at the surface or lower altitudes indicates a lack of hail in a thunderstorm.
F
Hail should be anticipated in __________thunderstorm, especially
_________
any
under anvil
A pressure change cycle affecting altimeters may occur in as little as _____
15 min
What is “St. Elmo’s Fire”?
low level static discharge
Microburst downdrafts can be as strong as ______________________ fpm.
6000
A microburst near the ground can extend approximately ___________ in diameter.
2 1/2 miles
Microburst wind shear can be as much as __________ near the surface.
90 knots
When no rain is present, pilots should be alert to _____________ as an
indication of microburst activity
see stuff blowing
T / F Multiple microbursts in the same general area are not uncommon and should be expected.
T
. Microbursts may be _______ if encountered at low altitude.
impossible to recover from
Name the characteristic that defines the following:
a. Tornado
b. Funnel cloud
c. Water spout
touches ground
does not touch down
touches water
Tornadoes are more frequently associated with
squall lines
T / F Although thunderstorms build and dissipate rapidly, they tend to move slowly and a pilot should
use weather radar plan a course between echoes.
F
Hazardous turbulence may extend __________ from the thunderstorm cloud.
20 miles
Circumnavigate an area of thunderstorms if the area has ____________ thunderstorm coverage.
3/5 or 60%
When flying at night in the vicinity of lightning, aircrew should _______
turn up cockpit instrument lights
Fog is a
ground based cloud
What makes fog especially hazardous to aviation?
forms rapidly
A small _________ spread is essential for fog to form.
temperature dew point spread
Conditions favorable for radiation fog are ___________ skies, ___________ wind, ___________
humidity.
clear
no
high
Advection fog forms when
moist air goes over cold surface
Three differences between advection fog and radiation fog are:
radiation fog burns off
advection can form under clouds
radiation forms over ground
Why is precipitation-induced fog especially critical?
other possible hazards
True or False: Low stratus clouds and fog frequently exist together.
T
Haze occurs in Stable / Unstable air.
stable
True or False: Haze layers often have definite tops above which the visibility is good.
True
Fog evaporates, but haze or smoke must be dispersed by
wind
Ceilings are defined as the height of the __________
above ______.
Base of cloud
ground
What is the difference between a cloud ceiling and an obscured ceiling?
good visibility below
The single cause of the greatest number of general aviation fatalities is
VFR in IMC
