NIFE Weather 6-3-2 Hazards Flashcards
2.202
Define turbulence
-Any irregular or disturbed flow in the atmosphere producing gusts and or eddies
2.203
List the intensities of turbulence used in Pilot Reports (PIREPs)
-Light, Moderate, Severe, Extreme (Relative to aircraft)
2.204
Define the terms used to report turbulence with respect to time
- Occasional (less than 1/3)
- Intermittent (1/3 to 2/3)
- Continuous (greater than 2/3)
2.205
Describe the causative factors that create the different types of turbulence
- Thermal: surface heating pushing the air mass up
- Mechanical: caused by differences in terrain
- Frontal: Lifting of warm air by a frontal surface leading to instability
- Wind shear: Steep gradient in wind velocity
- Jet stream: Produced by fast wind shears at high speeds just below the tropopause.
2.206
Describe how thermal turbulence develops
Surface heating pushes the air mass up causing instability
2.207
Describe how mechanical turbulence develops
Differences in terrain cause shift in air mass i.e. buildings, mountains, and water
2.208
Describe how frontal lifting creates turbulence
Warm air is lifted by a frontal surface leading to instability, or by abrupt wind shift between the warm and cold air masses.
2.209
Describe how temperature inversions are examples of wind shear turbulence
- Turbulence can occur at the boundary between the inversion layer and the surrounding atmosphere
- may cause a loss of lift
2.21
Describe the primary hazard of low level wind shear turbulence
-Can produce loss of lift by producing a downdraft or changing a headwind to a tailwind
2.211
Describe how jet streams are examples of wind shear turbulence
-Rapid change of wind speed within a short distance of the jet core is particularly significant
- If temperature rises–climb
- If temperature falls–descend
2.212
Describe the recommended procedures for flying through turbulence
-Monitor outside temperature for a minute or two
- If temperature rises climb
- If temperatures fall descend
- If temperatures remain the same either climb or descend
2.213
Describe structural icing
Ice forming on the airfoils changing the camber and weight of the aircraft
2.214
State the requirements for the formation of structural icing
- The atmosphere must have super-cooled visible water droplets
- The free air temperature and the aircraft’s surface temperature must be below freezing
2.215
State the temperature range most conducive to structural icing
- The smaller the droplets the lower the freezing point
- Freeze between -10C and -40C
- Icing is possible in any cloud below 0C
2.216
Identify the hazards of aircraft icing
- Icing decreases lift, increases drag, weight, fuel consumption, and stall speed.
- Can alter the shape of the airfoil changing the angle of attack.
2.217
Describe the types of engine icing
Induction- Ice buildup in the inlets (can occur above freezing due to increase in static pressure)
Compressor- Ice formation on the compressor inlet screens and compressor inlet guide vanes will restrict the flow of inlet air, eventually causing flame out
2.218
Identify the procedures to minimize or avoid the effects of icing
- Anti-icing/De-icing equipment
- Avoid icing forecasts
- Avoid clouds with 0C to -20C
- Avoid freezing precipitation
- Avoid low clouds above mountains
- Avoid steep turns into ice
- Change altitude to temperatures above freezing or below -20C
Avoid flying parallel to fronts
2.219
Describe the parameters that define fog
- Based at or within 50ft of the surface
- Greater than 20ft in depth
- Reduces visibility to less than 5/8 of a statute mile
- Shallow, is no more than 200ft in height
2.22
Define obscuring phenomena
- Any collection of particles that reduce horizontal visibility to less than six miles
e. g. fog, smoke, volcanic ash, and blowing spray
2.221
State the requirements for fog formation
- Condensation nuclei must be present in the air
- The air must have a high water content (low dew point spread)
- light surface winds must be present
2.222
Describe the two main types of fog
-Radiation: Occurs due to nocturnal cooling, usually on clear nights, when the Earth releases relatively large amounts of radiation to the atmosphere, cooling the surface.
Advection: Warm, moist air moves over a cold surface and the air is cooled to the dew point (sea fog) can last weeks (land at day/sea at night)
2.223
Describe the hazards associated with thunderstorms
-Strong wind gusts, severe turbulence, lightning, heavy rain showers, severe icing, and possible hail and tornadoes
2.224
Describe the signs and hazards associated with microbursts
- Strong headwind changes to a strong tail wind (decreasing lift)
- Doppler calls for low-level wind shears
- Visual cues are virga, localized blowing dust, rain shafts, roll clouds, and lightning or tornado like activity
2.225
Describe the recommended techniques for avoiding thunderstorm hazards
- Get latest radar report and PIREP
- Wait out the storm
- Avoid the thunderstorm by at least 20 miles of the anvil
- Don’t fly below in mountainous terrain
- Always avoid flying through a thunderstorm
