JX104 - Weather Hazards Flashcards
Define each type of turbulence:
Light Turbulence: Momentary slightly erratic changes
Moderate Turbulence: Larger changes in altitude, DEFINITE STRAIN AGAINST SEAT BELTS AND SHOULDER STRAPS** (know for test)
Severe Turbulence: Large abrupt changes in altitude or attitude, large variations in airspeed, aircraft may be momentarily out of control
Extreme Turbulence: Aircraft violently tossed about, control difficult or impossible
What are the 4 classifications of turbulence?
Light
Moderate
Severe
Extreme
State the duration of each turbulence
Occasional
Intermittent
Continuous
Occasional - Less than 1/3 of the time
Intermittent - 1/3 to 2/3 of the time
Continuous - More than 2/3 of the time
What are 5 causative factors of turbulence?
Thermal (Lifting from heat. Also called convective)
Mechanical (Caused by buildings or other obstructions)
Frontal (Caused by fronts)
Wind Shear (Can be caused by mountainous terrain and other factors)
CAT (Clear Air Turbulence usually in the Jet Stream)
What are Rotor Clouds?
Form downwind from and parallel to mountain range; Cylindrical shape; Downward flow has been known to reach the ground
What are the rules of thumb for turbulence proximity/intensity for EXTREME, SEVERE, and MODERATE?
50 knots wind at altitude of peak - EXTREME
Up to 150 miles downwind - SEVERE*** (know for test)
Up to 300 miles downwind - MODERATE
What are some ways to avoid mountain wave turbulence?
Cicumnavigate if possible
Fly 50% higher than peak*** (Know for test)
Avoid rotor, cap, lenticular clouds
Approach mountain range at 45º angle
In Frontal Turbulence, how much turbulence is there in a warm front?
No turbulence in warm front due to little or no liffting
Wind Shear Turbulence: Suddne change in wind speed or direction over ____ distance, _______ or ________
Short distance, vertically or horizontally
What type of frontal activity is likely to produce the most turbulence?
Fast moving cold front
What temperature can you get Clear Icing? Rime? Mixed?
Clear 0 to -10º C
Rime -10 to -20º C
Mixed -8 to -15º C
What are some Icing Requirements?
Visible moisture Temperature 0º to -20º Structure of airplane below freezing Super-cooled water droplets Liquid water at air temps below freezing Clouds are the most common form
What type of clouds, icing, and rate of accumulation is associated with an occluded front?
Stratus and Cumulus
Mixed Icing
Rapid and Heavy accumulation
Very widespread area of icing
Does icing affect your attitude indicator?
No
There is a high probability for induction icing with air temperatures ___ºC and below.
+10ºC
What are the greatest hazards associated with induction and compressor icing?
Reduced airflow and FOD
Define Icing TRACE LIGHT MODERATE SEVERE
TRACE: Ice becomes perceptible
LIGHT: Rate of accumulation can be a problem over extended time, over one hour** Know for test
MODERATE: rate of accumulation potentially hazardous
SEVERE: Rate of accumulation extreme, De-ice/anti-ice equipment fails to reduce
What is flight visibility?
See and identify
Prominent unlighted objects by day
Prominent lighted objects at night
What is Prevailing Visibility?
Greatest horizontal visibility
Equaled or exceeded throughout over half horizon circle
Measured in statute miles
What is Slant Range Visibility?
Distance on final approach at which runway environment in sight
Must be reported by PIREP
Indicates when aircraft will “break out” on final
What is Runway Visual Range (RVR)?
Horizontal distance seen by looking down runway from approach end
Reported in meters or hundreds of feet
What is a Ceiling?
Lowest broken or overcast layer OR Vertical visibility (VV) into an obscuring phenomenon
What are the characteristics of Fog:
Base at or within ___ feet of surface
Greater than ___ feet thick
Reduces visibility to less than ____ miles
Base at or within 50 feet of surface
Greater than 20 feet thick
Reduces visibility to less than 5/8 mile
All 3 conditions must be met to be fog
What are two types of fog?
Radiation
Advection
What causes Radiation fog?
Nocturnal radiation cooling
What dissipates Advection Fog? Radiation Fog?
Advection Fog can only be dissipated by a wind shift
Radiation Fog can be dissipated by solar heating
What category of turbulence is characterized by large variations in airspeed and abrupt changes in attitude and altitude?
Severe Turbulence
What are the 3 types of wind shear turbulence?
Temperature Inversion
Jet Stream
Gusty Winds
When may Extreme Wind Shear Turbulence be formed?
When strong inversion exists near the ground
