Wx Flashcards
For every 1000ft of rise the temperature drops ___ degrees C
2
What is the first layer of the atmosphere ____
Troposphere
The ____ zone is where the air temperature remains constant with height
Isothermal
The _____ absorbs energetic ultraviolet solar energy
Ozone
Becoming oxygen starve is known as ___
Hypoxia
What are the recognized fronts and their characteristics?
- Cold Fronts: cold air mass overtaking/replacing warmer air (TS/Ltg/+RA/IC/GR)
- Warm Fronts: warm air mass overtaking/replacing colder air (FZ/IC/Low ceiling)
- Occluded Fronts: Cold front overtakes warm front and lifts it completely from the ground
- Stationary Fronts: Cold/Warm front does not move
What is the most noticeable property of air
Mobility
What forces drive the winds on earth
- Heat of sun
- Rotation of earth on its axis
The ___ are Westerly winds that can reach up to 300kts but generally maintain between ___ and ____
Jet Stream / 100 and 150 kts
The strongest jet streams are usually between ___ and ___ depending on latitude and season
25,000 and 40,000 ft
Earth’s surface is more than ___ water
2/3
The ___ keeps the atmosphere supplied with moisture and aids in producing temperature and pressure changes
Hydrologic cycle
___ is the most important single element in the production of the clouds and other visible weather phenomena
Water vapor
The ___ the air, the more water vapor it can hold before reaching saturation and condensation occurs
warmer
The higher the temperature, the more ____ the air is capable of holding
water vapor
___ is the ratio of the amount of water vapor actually in the air, to the maximum amount that the air can hold at that temperature
Relative Humidity
____ is the temperature, at atmospheric pressure, to which air must be cooled to become saturated
Dew Point
___ should be alert for the possibility of fog or low cloud formation at any time when the surface temperature is within ___ degrees F of the dew point
Aircrew / 4 degrees F
___ are formed by very small droplets of water collecting on water absorbent particles of solid matter in the air
Clouds and Fog
____ absorb so much heat during the day, their temperature falls slowly
Large Objects
___ is used because it is one of the heaviest liquids at normal temperatures
Mercury
What forces mercury to rise in a barometer
Atmospheric pressure
The US military and civil weather agencies express altimeter settings in ___ of mercury
Inches
What is the weight of the air above an airport known as?
Station Pressure
Air ___ as it becomes warmer and ____ as it cools
expands / contracts
T / F - Aircrews can learn to recognize pressure patterns on charts because they frequently happen and are associated with numerous flying hazards
True
T / F - A clear sky guarantees the absence of turbulence
False
___ is pressure altitude corrected for nonstandard temperature
Density altitude
Hot days cause the air to become ___ and its density at the field is equivalent to a higher altitude
Thinner
Higher density altitude ___ aircraft performance
reduces
____ is used above the transition altitude (18,000 ft)
QNE Altitude setting
___ is a pressure reading which when set will cause the instrument to read its true heading above MSL
QNH Altitude setting
Aircrews must exercise extreme caution in conducting operations at a location using ____ setting
QFE altitude setting
T / F It is the aircrew’s responsibility to ensure terrain avoidance
True
What are the 3 factors that determine indications of the pressure altimeter
- Atmosphere Pressure Level
- Mechanical Displacement of the indicator needles: the altimeter setting
- Instrument error
If air is much ___ than the standard atmosphere, the actual aircraft altitude will be lower than the altimeter indicates
Colder
If the air is ___, the aircraft will be higher than the altimeter indicates
Warmer
____ is a scheduled observation taken between 55-59 minutes past the hour
METAR
___ are a sudden, brief increase in speed during the 10 mins immediately preceding the observation
Gust
The term ___ is used when the speed increases by at least 16kts and sustained at 22kts for at least 1 min
Squall
RVR is reported when the prevailing visibility is one statute mile or less and/or the RVR for the designated runway is ___ / ___ or less
6000ft / 1830m
VC means ___
Vincity
SH means ___
Showers
TS means ___
Thunderstorm
DZ means ___
Drizzle
IC means ___
Ice Crystals
___ are short duration and small in size relative to thunderstorm complexes, but they may have 100kts of wind and severe downdrafts
Microburst
Who is the primary point of contact for briefings and all operational weather
CWT
T or F - Aircrew should ask how the weather will affect our mission
True
OWSs need a minimum of ___ notification to prepare a weather briefing
2hrs
What is a MEF?
Mission Execution Forecast (MEF-DD Form 1751): process that allows the CWT to efficiently prepare your actual mission briefing
The turbofan engine is a byproduct of combining the basic ____ and ___ engines
Turbojet and Turboprop
The airflow from the fan stages produces thrust much like a _____
Propeller thrust
The action from these blades is much like that of a ___, although the motion of the propeller blade is more complex than that of a ____
Wing / Wing
Slip is the difference between the ____ pitch of the propeller and its ___ pitch
Geometric pitch / Effective pitch
The ____ is the angle between the blade chord and the plane of the propeller’s rotation
Blade angle
____ is essential in order to obtain efficient propeller operation
Twist
Aerodynamically, ___ is the result of the shape and angle of the propeller blade
Propeller Thrust
The turboprop engine is rated by the amount of ___ it applies to the propeller
Shaft Horsepower
99% of the atmosphere lies within ____ of the earth’s surface
19 miles
The atmosphere is composed of what gases
Nitrogen - 78%
Oxygen - 21 %
Other - 1% (Argon 0.93%)
____ is the rate at which the air temperature decreases with height
Temperature lapse rate
The Troposphere extends from the earth’s surface up to ___ ft
36,000 ft
The boundary separating the troposphere and stratosphere is called the ____
Tropopause
____ are high winds that meander in a narrow channel, like an older river, often at speeds exceeding 100kts
Jet Stream
The second region of the atmosphere is the ___
Stratosphere
The ___ is considered the middle sphere
Mesosphere
The ___ is considered the hot layer above the mesosphere
Thermosphere
___ is one of the most important weather parameters that aviators need to understand
Atmospheric Pressure
In the Standard atmosphere, sea level pressure is ___ Hg or ___ millibars
29.92 inches Hg or 1013.2 millibars
What’s the difference between A01 and A02
A01 - ASOS without rain vs snow discriminator
A02 - ASOS with rain vs snow discriminator
___ is any surface designed to obtain a reaction upon itself (producing lift) from the air through which it passes through
Airfoil
The ____ of a wing is the distance from the leading edge to the trailing edge and is represented by a straight line called the ____
Chord / chord line
___ is the force of gravity acting downward upon anything that goes into the aircraft (crew, fuel, cargo)
Weight
When ___ is increased, it also ___ drag
Airspeed or AoA / Increased
When __ __of the engine is increased, ___ momentarily exceeds drag and airspeed will ___., provided straight and level flight is maintained
Thrust Output / Thrust / Increase
What are the factors affecting lift and drag?
- Wing Area
- Air Foil Shape
- External Induced Air Foil Change
- Air Speed
- Air Density
The lift and drag acting on a wing are roughly proportional to the ____, meaning that if the ___ is ___ with all variables remaining the same, the lift and drag created by the ____ will be ____
Wing area / Wing area / Doubled / Wing / Doubled
A raised ___ reduces the lift on the wing by decreasing the curvature of a portion of the wing
Aileron
As the air density ___, lift and drag ____. as air density ___, lift and drag decreases
Increases / Increases ; Decreases / Decreases
Lift and drag are directly proportional to the ____
Density of the air
Square of the velocity of air
During take-off and landing, the effectiveness of nose wheel steering is dependent on _____
Friction
Thrust is needed to overcome ___ and ___
Rolling friction and aerodynamic drag
The primary purpose of wing flaps and wing slats is to allow the aircraft to ___ and ___
takeoff and land at low airspeeds
T or F: Extending flaps and slats increases drag only
False: it increases lift and drag
___ is the true altitude (MSL) corrected for atmospheric pressure (barometric pressure) variance from the ICAO standard day
Pressure altitudes
___ is pressure altitude corrected for nonstandard temperature
Density Altitude
What % of headwind component will be used for mission-essential missions only
50%
___ is a measurement of friction between the aircraft tires and the runway
Runway Condition Reading (RCR)
T or F: Grooved/porous runway improve aircraft braking
True
___ is the average depth and type of runway surface covering to the nearest one-tenth inch
Runway Surface Condition (RSC)
___ is the result of marked loss of coefficient of friction between the tires and runway
Hydroplaning
A ____ shortens take-off ground run and the Critical Field Length (CFL)
Downhill slope
___ increases take-off ground run and increases CFL
Uphill slope
___ is used when nothing else will save life, property, or mission objective
(Take-off power) Maximum Effort
___ produces close to the maximum thrust of which an engine is capable, but compromise some amount of thrust in the interest of extending engine life
Takeoff Rated Thrust (TRT)
TRT is expressed in terms of ___ and ___
Engine Pressure Ratio (EPR) and Fan Speed (N1)
Takeoffs with bleed air off are either ____ or ____
- mandated under prescribed conditions
- left to the discretion of the aircraft commander
____ are the primary indication of available on turboprop engines
Inch-pounds of torque
___ combines the EPR/N1, which vary with temperature at a given altitude, with the actual altitude to produce a statement of thrust
Thrust Factor (TF)
___ is a reference number that combines EPR/N1, temperature and pressure altitude
Air Performance Number (APN)
___ adds the effect of density altitude on the airframe to the thrust of the engines
Takeoff Factor (TOF)
___ combines static EPR/N1, temperature, and pressure altitude to arrive at a reference number which also incorporates the effect of density altitude on the airframe
Ground Performance Number (GPN)
____ combines thrust developed by the engines with the aircraft gross weight to arrive at a reference number which expresses the aircraft weight to power ratio
Climb Out Factor (COF)
___ is the airspeed used during the climb which compromises between the airspeed for max climb rate and the airspeed that produces the most efficient engine operation
Climb speed
___ is the height an aircraft will climb in a given horizontal distance
Climb gradient
___ is the minimum speed required to maintain directional control with an outboard engine inop and the remaining engines at takeoff thrust
Ground Minimum control speed (VMCG)
___ is the speed at which an aircraft can have an outboard engine fail and still maintain directional control using full rudder deflection and not more than 5 degrees of bank
Air Minimum Control Speed (VMCA)
___ is the distance required to accelerate on all engines, to critical engine failure speed (VCEF), experience engine fail at VCEF, and either takeoff/abort
Critical Field Length (CFL)
___ is the speed at which an aircraft can accelerate on all engines, have an engine failure, and either stop within the CFL or takeoff with the remaining engines
Critical Engine Failure Speed (VCEF)
___ is the max speed an aircraft can accelerate with takeoff power and stop within the remaining runway
Refusal Speed (VR)
___ is the speed reached during the takeoff run that the aircraft transitions from a 3-point attitude to takeoff attitude
Rotation Speed (VROT)
___ is the speed the aircraft must accelerate before liftoff occurs
Take-off speed (VTO)
___ is the max ground speed that a tire can structurally withstand during taking/landing
Tire Placard Speed (TPS)
___ is the tire placard speed corrected to either Calibrated Airspeed in Knots (KCAS) or Indicate Airspeed in Knots (KIAS)
Tire Limit Speed (TLS)
___ is the highest speed the aircraft can stop without exceeding the max energy absorption capability of the brakes
Maximum Braking Speed (VBMAX)
___ is the distance required to accelerate to takeoff speed
Takeoff Ground Run
___ compensates for differences between the center of gravity and the center of lift
Horizontal Stabilizer Trim Settings
___ allows for comparison of takeoff vs time/dist and can be aborted at a predetermined point for substandard performance
Acceleration Check Speed
Flying segments of the approach to landing at approach/reference speed plus incremented airspeed increase are known as ____
Approach (VAPP) and Reference (VREF) Speed
__ is the airspeed at which we cross the runway threshold, normally at a height of 50ft
Threshold Speed
___ is the speed that we actually touchdown on the runway
Touchdown Speed
___ is normally based on the aircraft crossing the runway threshold at a height of 50ft at the threshold speed
Landing Distance
___ is the required distance after touchdown to stop the aircraft
Landing Ground Roll
___ is the point all the forces of flight will equal
Absolute Ceiling ( Rate of climb = 0 FPM)
Service Ceiling is what rate of climb
100 FPM
Formatting Ceiling is what rate of Climb
200 FPM
Cruise Ceiling is what rate of Climb
300 FPM
Performance Ceiling is what rate of climb
400 FPM
Combat Performance Ceiling is what rate of climb
500 FPM
What are the Basic Cruise Performance Profiles
Constant Altitude, Cruise Climb Cruise, and Optimum Step Climb
___ consists of an aircraft climbing to a cruise altitude and remaining there until descent (worst gas mileage)
Constant Altitude
___ consists of climbing to its optimum altitude, starting a cruise and as the aircraft gets lighter from fuel burn off, we allow the aircraft to climb (best gas mileage)
Cruise Climb Cruise
___ is the compromise between the Constant Altitude and Cruise Climb Cruise Profiles. Allows for ATC coordination
Optimum Step Climb
__ is very seldom used on large aircraft; set cruise power and leave it alone
Constant Power
__ is used often once cruise speed is established and will be maintained throughout the flight
Constant Speed
___ gives the best gas mileage for the conditions of the day
Maximum Range
__ is flying at the airspeed that will give us our lowest fuel flow; staying in the air the longest
Endurance
___ is where we sacrifice a little range for an increase in airspeed. Sacrificing 1% of range = 5% increase of speed
Long Range
___ gives the greatest amount of time when flying a constant altitude; used by search/rescue
Best Endurance
___ obtain a very high rate of descent when air traffic control or mission dictates
Rapid Descent
___ descents are made when the need for a faster than normal change in altitude exists
Penetration
____ descents are the most common and provide fuel economy and passenger/crew comfort
En Route Descent
The curvature/departure from the chord line is known as ____
Camber
What are the type/characteristics of camber
- Zero: no curves
- Negative: concave/inward curve
- Positive: upward curve
___ is the angle formed by the longitudinal axis of the aircraft and the chord of the wing
Angle of Incidence
___ is the angle between the wing chord line and the direction of the relative wind (chord line and flight path)
Angle of Attack
Air that can no longer flow smoothly over the wing’s upper surface due to the separation of the boundary layer and will eventually cause a stall is known as ____
Burble Point
Drag increases ___ as much as increased speed
Twice
SPECI (Special Rpt) is an unscheduled observation taken when ____
predefined condition criteria change occurs
What is the source that drives the winds
The Sun
The earth’s ____ is the steering mechanism
Rotation
___ is the density of water vapor in the air
Absolute Humidity
When the air has all the water vapor it can hold, it is ____
Saturated
When the air contains all the water vapor possible to hold at its current temperature, the relative humidity is ___
100%`
___ is the most common type of wind and is the average direction/speed over 2 minutes
Prevailing(Sustained)
____ is reported if the direction varies by 60 degrees and speeds greater than 6kts
Wing Variability
On average, thrust constitutes appx ____% of torque, absorbed by the propeller, and ___% are lost in friction and slippage
80% / 20%
Turbofan consist of what sections ___, ___, ___, ___, and ___
- Fan
- Compressor
- Combustion
- Turbine
- Exhaust
Use ___% of tailwind component as the effective wind in planning takeoff/landing performance
150%
Use __% of headwind/tailwind when computing accel check, max braking, or tire limit speed
100%
Runway Condition Readings are the average reading of the total runway length within ___ ft of the runway centerline
20ft
