JX Weather (CBT) Flashcards

1
Q

Change of 1.0 inHg changes the altimeter by how many feet

A

1,000 feet

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2
Q

You change your altimeter setting from 29.92 to 29.64. What will your altimeter indicate?

A

An decrease in altitude

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3
Q

You change your altimeter setting from 29.92 to 30.60. What will your altimeter indicate?

A

A increase in altitude

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4
Q

For every 11 deg C, how much of an altimeter error could you expect?

A

4%

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5
Q

With standard pressure (29.92), what will your altimeter indicate if OAT is lower than standard?

A

It will read an altitude higher than you actually are

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6
Q

With standard pressure (29.92), what will your altimeter indicate if OAT is higher than standard?

A

It will read an altitude lower than you actually are

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7
Q

Define indicated altitude

A

Altitude as it is displayed on your altimeter

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8
Q

Define absolute altitude

A

The acft’s altitude above the ground (AGL)

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9
Q

Define true altitude

A

The acft’s altitude references to sea level (MSL)

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10
Q

Define pressure altitude

A

Altitude above the standard datum plane (29.92 inHg)

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11
Q

Define density altitude

A

Pressure altitude corrected for nonstandard temperature deviations. (Not a reference altitude, but rather indication of acft performance)

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12
Q

Pure dry air contains what gasses and how much water vapor

A

Roughly:
78% nitrogen
21% oxygen
1% Other (10 gasses)
The atmosphere contains about 0-5% water vapor by volume

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13
Q

Troposphere dimensions

A

Average of 55,000 feet at the equator to 28,000 at the poles
Hight above the U.S. is about 36,000

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14
Q

Significance of the troposphere

A

Nearly all weather occurs in this layer

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15
Q

Define lapse rate

A

temp decrease with an increase of altitude

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16
Q

Define tropopause

A
  • An abrupt change in temperature decrease with an increase of altitude
  • Transition layer between the troposphere and the stratosphere
  • Average hight of 36,000 over the U.S.
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17
Q

Where do the strongest winds occur

A

Just bellow the tropopause

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18
Q

Tropopause characteristics

A
  • Strong winds
  • Mod-sev turbulence
  • Haze layer is common
  • Temp is constant with altitude
  • Normally the coldest area in the lower atmosphere
  • Contrails occur… #Chemtrails
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19
Q

Stratosphere

A

Above the tropopause

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20
Q

Stratosphere characteristics

A
  • increasing temperature as altitude increases (inversion) to approx 66,0000
  • smooth air
  • excellent visibility
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21
Q

What is an ELR

A
  • Existing lapse rate
  • Gives meteorologist the type of weather that exists
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22
Q

3 types of ELRs

A
  • Standard
  • Isothermal
  • Inverted
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23
Q

What is the standard lapse rate (temp)

A

2 deg C (or 3.5 F) per 1,000 feet

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24
Q

What is Isothermal lapse rate

A

temp is constant with an increase in alt

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25
Q

What is inverted lapse rate

A

temp increases with an increase in alt (temp inversion)

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26
Q

Characteristics of an inverted lapse rate

A
  • Few hundred - few thousand feet thick
  • stable air
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27
Q

Average weight of air per square inch at sea level (standard conditions)

A

14.7 lbs

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28
Q

What is the relationship with altitude and pressure

A
  • Always decreases with altitude
  • pressure decreases more rapidly in the lower layers of the atmosphere (b/c air density)
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29
Q

What is inHg

A

measure of the high of a column of mercury that can be supported by atmospheric pressure

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30
Q

What is mb

A

The millibar is a direct measure of pressure defined by force per unit area

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31
Q

Standard day at sea level

A
  • 29.92 inHg & 15 deg C (59 F)
    or 1013.2 mb
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32
Q

What is the standard lapse rate (pressure)

A

1 inHg (or 34 mb) per 1,000 feet

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33
Q

What is station pressure

A

atmospheric pressure measured directly at an airfield or weather station

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34
Q

What do surface analysis charts show

A
  • high and low pressure systems
  • isobars
  • ridges (high pressure/good wx)
  • trough (low pressure/bad wx)
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35
Q

What are isobars

A
  • Lines of equal (sea level) pressures
  • depict horizontal distribution of pressure
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36
Q

Winds on charts will depict wind in relation to

A

True north

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37
Q

Winds reported from ATIS, tower, or RSU are in relation to

A

Magnetic north

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38
Q

What are the 3 station model wind indicators

A
  • half barb = 5 kts
  • barb = 10 kts
  • penant = 50 kts
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39
Q

What weather conditions do a station model depict?

A
  • Wind direction
  • Wind speed
  • sky cover (circle)
  • temperature (top left)
  • dew point (bottom left)
  • sea level pressure (top right)
  • pressure change (bottom right) +/- in last 3 hrs
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40
Q

How far apart are isobars spaced?

A

4 millibars apart

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41
Q

Wind characteristics in surface charts

A
  • generally move in the same direction between pressure systems
  • most cases, almost parallel to isobars
  • High pressure system = clockwise
  • Low pressure system = counterclockwise
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42
Q

Define pressure gradient

A

rate of change in a direction perpendicular to isobars

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43
Q

What is PGF

A

pressure gradient force

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44
Q

How is PGF represented

A

isobar spacing

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45
Q

Atmospheric circulation moves air by

A

mean of ascending and descending currents

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46
Q

descending air generates what pressure system

A

high pressure system

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47
Q

air moving upward generates what pressure system

A

low pressure system

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48
Q

Air spreads out, produces horizontal flow

A

high pressure system

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49
Q

air tries to converge toward the center

A

low pressure system

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50
Q

Coriolis force

A
  • force created by earths rotation
  • diverts wind to the right with respect to its initial direction (regardless of pressure system)
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51
Q

gradient winds

A
  • combined force between the pressure gradient force and the Coriolis force
  • flow perpendicular to pressure gradient force (parallel to isobars)
  • results in northern hemisphere circulation (counterclockwise = low pressure system
    clockwise = high pressure systems)
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52
Q

where are gradient winds found

A

above 2,000 ft AGL

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53
Q

When the PGF, Coriolis, and friction force balance (bellow 2,000ft AGL)

A

wind flows at a 45 deg across isobars from high to low pressure

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54
Q

wind speeds ______ with height through the troposphere; reach a maximum near the ______

A

increase; tropopause

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55
Q

Jet stream

A
  • 50 knots or more (100-150; excess of 250)
  • moves vertically and horizontally
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56
Q

two types of jet streams

A
  • polar jet
  • subtropical jet
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57
Q

characteristics of jet streams

A
  • greatly influence weather patterns
  • average height of 30,000 MSL
  • wind speeds 100 - 150 kts (can reach in excess of 250 kts)
  • 1,000 - 3,000 miles long
  • 100 - 400 miles wide
  • 3,000 - 7,000 feet deep
  • move west to east
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58
Q

Valley wind

A

idk

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59
Q

Mountain wind

A

idk

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60
Q

dew point

A

the temperature that saturation occurs

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61
Q

difference between temperature and dewpoint

A
  • dew point depression
  • temperature dew point spread
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62
Q

relative humidity

A

percentage of the air saturation

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63
Q

3 characteristics of precipitation

A
  • showers
  • continuous
  • intermittent
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64
Q

Characteristics of showery precipitation

A
  • starts/stops
  • changes intensity or sky conditions rapidly
  • associated with cumuliform clouds
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65
Q

Characteristics of continuous precipitation

A
  • steady
  • gradual change
  • associated with stratiform clouds
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66
Q

Characteristics of intermittent precipitation

A
  • starts/stops at least once per hour
  • can be showery or steady
  • associated with both cumuliform and stratiform
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67
Q

precipitation forms

A
  • rain
  • drizzle
  • frozen
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68
Q

how are clouds generally categorized

A
  • high
  • middle
  • low
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69
Q

characteristics of low clouds

A
  • surface to 6,500 agl
  • hazardous to flight b/c of proximity to ground
  • turbulence: non-moderate
  • precipitation: drizzle or light rain
  • if below freezing: can produce icing (accumulates faster due to clouds being denser)
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70
Q

characteristics of middle clouds

A
  • 6,500 to 20,000 agl
  • names contain “alto” prefix
  • composed of ice crystals, water droplets, or a mix
  • rain, snow
  • icing is common
  • turbulence may be encountered
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71
Q

characteristics of high clouds

A
  • 20,000 to 40,000 agl
  • names contain “cirro” prefix
  • composed of primarily ice crystals
  • contain no precipitation
  • not an icing hazard
  • little effect on flight ops except for mod turbulence
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72
Q

Special clouds (types)

A
  • towering cumulous
  • cumulonimbus
  • nimbostratus
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73
Q

Cumulous & Cumulonimbus cloud characteristics

A
  • found in low to middle and extend the the high cloud heights
  • nearing thunderstorm stage
  • produce heavy, showery precipitation
  • mod turbulence
  • icing common above the freezing level
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74
Q

Cumulonimbus cloud characteristics

A
  • also referred to as “CB”
  • very dangerous
  • severe turb
  • hail/icing
  • lightening
  • If extends past tropopause = severe thunderstorm
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75
Q

Nimbostratus cloud characteristics

A
  • bases can be as low as 1,000 AGL
  • heavy, continuous rain, snow, or ice pellets
  • poor visibility
  • low ceilings
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76
Q

What is denser, cold or warm air?

A

cold air

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77
Q

Four methods that air masses are lifted

A
  • convergence
  • frontal
  • orographic
  • thermal
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78
Q

convergent lifting

A

two air masses or parts of a single air mass converge

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79
Q

frontal lifting

A

cold fronts moving through the an area, lifting the warm front over it

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80
Q

orographic lifting

A

wind against a mountain side pushing up

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81
Q

thermal lifting

A

(Convective lifting) warm surface pushing cold air up by “intense solar heating”

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82
Q

Conditions you’d expect when stratiform clouds are present

A
  • smooth air
  • poor visibility
  • steady winds
  • steady precipitation
  • rime icing
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83
Q

Conditions you’d expect when cumuliform clouds are present

A
  • rough air
  • good visibility
  • gusty winds
  • showery precipitation
  • clear icing
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84
Q

Inversions, low clouds, fog, rising temps while climbing would indicate what conditions

A

stable

85
Q

dust and rapidly decreasing temps while climbing would indicate what conditions

A

unstable

86
Q

Define air mass

A

Body of air with uniform temp and moisture conditions

87
Q

temperate zone

A

region between 30 and 40 deg North latitude (US)

88
Q

Air masses are named according to their ___, ___, and ____.

A

moisture content; location; temperature

89
Q

What indicates stability of air mass

A

temperature
(warm = stable, cold = unstable)

90
Q

Surface front

A

point where front comes in contact with the ground

91
Q

frontal zone

A

area that encompasses the weather on either side of the front

92
Q

3 characteristics of fronts

A
  • always located in a trough of low pressure
  • cold fronts are faster than warm fronts
  • frontal passage is usually accompanied by a 90 deg shift in wind direction
93
Q

Flying through a front can show the following indication

A
  • initial pressure decrease, then rises immediately (after frontal passage)
  • wind shift (possible severe wind shear)
94
Q

What clouds produce steady precipitation and little to no turbulence

A

Stratiform
(PREVIOUS TEST QUESTION –> OPTIONS MIGHT INCLUDE NIMBOSTRATUS AND STRATUS. ANSWER IS STRATUS)

95
Q

What clouds produce showery precipitation and turbulence

A

cumuliform

96
Q

How does the angle of the frontal slope influence weather

A

steep - generally associated with severe weather, showery, move fast
shallow - extensive cloudiness with steady precipitation

97
Q

describe a cold front

A

more dense (wedges under warm air), steep slope, associated with unstable conditions when met with warm front

98
Q

Signs a cold front is passing through

A

generally wind speed increased, baro pressure decreases-then rises sharply, lower cloud bases and rain/snow, win shifts 90 deg SW to NW, then clear skies and fair weather

99
Q

Fast moving cold front occurs in a _____.

A

narrow band (sever)

100
Q

Slow moving cold front occurs in a _____.

A

larger area (less severe, lasts longer)

101
Q

squall line

A
  • line of violent thunderstorms (dashed-double dotted purple lines)
  • develop 50-300 miles ahead of cold fronts (sometimes nowhere near)
  • very dangerous
102
Q

Warm frontal passage characteristics

A
  • overtakes colder air by going over the top (creates broad area of cloudiness)
  • steady precipitation
  • reduced visibility
  • typically slower than cold fronts
  • SE to SW wind shift
103
Q

Stationary front

A
  • frontal boarder between air masses show little or no movement (neither replacing each other)
  • 180 deg wind shift
  • weather similar to warm front but less intense
  • weather of a stationary front may last for several days
104
Q

how far ahead of a warm front can the associated cloud system reach?

A

500-700 miles

105
Q

Occluded fronts

A
  • form when a faster moving cold front overtakes a slower moving warm front
  • 180 deg wind shift
  • associated weather will be a combination of both types
106
Q

difference between cold and warm occluded fronts

A

depends on which front remains in ground contact

107
Q

Where is the most severe weather located in an occluded front?

A

100 miles south to 300 miles north of the frontal intersection

108
Q

what is a dry line

A

“dew point line” is a boundary between moist and dry air masses

109
Q

describe a dry line

A
  • dense dry air wedges under the moist air
  • temp will be similar on both sides (not a large temp gradient)
  • a rapid rise in moist air can result in severe weather (tornados, hail, high winds)
110
Q

What are the two groups of icing

A

Structural and engine icing

111
Q

When does structural icing occur

A

formation of ice through clouds or liquid when the air and skin temp is equal or less than 0 deg C

112
Q

what is the main concern for structural icing?

A

loss of aerodynamic efficiency due to an increase in drag and decrease in lift

113
Q

engine icing is also known as what

A

induction icing

114
Q

when does engine icing occur

A

when ice forms in the induction or compressor sections of the engine

115
Q

what is a result of engine icing

A

FOD and compromised performance

116
Q

Sources of moisture in regards to icing

A
  • super-cooled water droplets
  • wet snowflakes
    -clouds (most common)
117
Q

what are super cooled water droplets

A

water droplets that retain liquid form although temp is bellow freezing (0 to -20, in some cases -40 deg C)

118
Q

True or False
Icing is possible in temps above freezing

A

True

119
Q

3 types of Icing

A
  • Clear
  • Rime
  • Mixed
120
Q

What is a major factor in aircraft icing

A

The shape of the aircraft

121
Q

Characteristics of clear Icing

A
  • between 2 to -10 deg C
  • lumpy and translucent/clear smooth
  • supercooled drops not freezing right away upon contact
  • tends to form horns or other complex shapes
122
Q

Characteristics of rime icing

A
  • between -10 to -15 deg C
  • rough, milky, opaque
  • formed by the supercooled droplets freezing instantaneously
  • conformal or wedge-shaped accretions
123
Q

Mixed Icing

A
  • between -15 to - 20 deg C
  • combination of clear and rime
  • when ice particles become embedded in clear ice
  • very rough/whitish
  • accumulates rapidly and tough to remove
124
Q

Icing generally found in cumulus clouds/unstable conditions

A

Clear icing

125
Q

Rime is dependent on what

A

low rate of catch of small supercooled water droplets

126
Q

Where does rime icing accumulate

A

edge of wings, antennas, pitot tubes, etc

127
Q

What icing typically forms when flying through stratiform clouds/stable conditions

A

Rime icing

128
Q

Where could you expect mixed icing?

A

colder portions of cumuliform clouds

129
Q

Different severities of icing

A
  • trace
  • light
  • moderate
  • severe
130
Q

trace icing

A
  • Ice becomes visible
  • accumulation slightly greater than sublimation
  • occasional use of anti ice
131
Q

light icing

A

rate of accumulation (¼ inch in 15-16 minutes) requires occasional use of ice protection systems to prevent accumulation

132
Q

moderate icing

A
  • rate of accumulation (¼ inch in 5-15 minutes) requires frequent use of ice protection systems to remove/prevent ice
  • unless actions taken, significant build ups of ice on airfoil and may present problem
133
Q

Severe icing

A
  • the rate of accumulation (¼ inch in less than 5 minutes) ice protection systems fail to remove accumulation of ice
  • usually a product of a clear or mixing icing encounter
  • may require immediate diversion
134
Q

There is a definite possibility of ______ icing, usually _____ or _____, within _____ to _____ miles ahead of a warm front.

A

moderate icing; mixed or clear; 100 to 200 miles

135
Q

Light rime can be noticed in the _____ up to _____ miles ahead of a warm front surface.

A

altostratus; 300 miles

136
Q

What front would be considered to have more of localized/spotty area of icing?

A

cold front

137
Q

_____ icing is usually limited to supercooled cumuliform clouds within _____ miles to the ____ of the cold front surface position.

A

clear icing; 100 miles; rear

138
Q

ice accumulation will have what affects on aerodynamic surfaces (7)

A
  • decrease climb rate
  • decrease cruise speeds
  • increase stall speed
  • decrease service ceilings
  • decrease missed approach performance
  • increase fuel consumption
  • decrease max range
139
Q

When icing is encountered, you should do what?

A

Climb or descend to exit icing condition

(POSSIBLE EXAM QUESTION: ANSWER IS SUPPOSEDLY “CLIMB”)

140
Q

Many times, it is more expedient to (a.) climb or (b.) descend above/below the moisture

A

climb above

141
Q

how are the static ports protected on T-6A from icing

A

airframe location

142
Q

how is the fuel system protected on T-6A from icing

A

external fairings

143
Q

How do you deice the canopy and what are the limitations?

A

heating; 150 deg F

144
Q

The most profound degradation of structural icing that manifests on aircraft performance usually occurs within _____ of ice accretion.

A

the first few minutes

145
Q

Visibility can be reported as (units)

A

statue miles, hundreds of feet, meters

146
Q

flight visibility

A

visibility from the cockpit

147
Q

Prevailing visibility

A
  • overal visibility
  • “greatest horizontal vis equaled or exceeded throughout at least half the horizon circle”
  • not continuous - merely needs to be at least half the horizon
148
Q

Slant range visibility

A
  • visibility from the cockpit to the ground
  • it must be reported in a PIREP
  • can be estimated by meteorologists
  • indicates when aircraft will break out on final
149
Q

RVR (runway visual range)

A
  • max distance that the runway/lights can be seen from a position above a a specified point on its centerline
    -reported in feet or meters
150
Q

SKC/CLR sky cover

A

0

151
Q

FEW sky cover

A

> 0/8 - 2/8

152
Q

SCT sky cover

A

3/8 - 4/8

153
Q

BKN sky cover

A

5/8 - 7/8

154
Q

OVC sky cover

A

8/8

155
Q

A ceiling refers to what

A

OVC, BKN, or obscuration

156
Q

what does VV006 mean

A

vertical visibility of 600 feet

157
Q

Two main types of fog

A
  • radiation fog
  • advection fog
158
Q

other types of fog (not radiation or advection)

A
  • upslope
  • frontal fog
  • freezing fog
159
Q

Radiation fog

A
  • developed only at night
  • dissipating by late morning
160
Q

advection fog

A
  • fog in motion (generated in one spot, wind takes it somewhere else)
  • typically coastal areas
161
Q

upslope fog

A
  • adiabatic cooling of rising air
  • warm air forced up a slope by wind
162
Q

frontal fog

A
  • conjunction with a frontal surface
  • precipitation induced (evaporation of falling rain)
  • warm frontal/stationary fog has greatest impact on aviation ops
163
Q

freezing fog

A
  • air temp is below freezing
  • if dense enough, may produce ice on aircraft surfaces
164
Q

conditions for fog to form (3)

A
  • condensation nuclei
  • air must have high water content
  • light surface winds (less than 10 kts)
165
Q

When will fog start to form?

A

when temp and dew point are about 5 F 3 deg C from another

166
Q

what are the ICAO indicators of a possible encounter with volcanic ash?

A
  • odor
  • haze
  • changing engine conditions
  • airspeed
    pressurization
  • static discharges
167
Q

List some effects of a thunderstorm

A
  • turbulence
  • downburst
  • microburst
  • tornadoes
  • icing
  • lightning
  • hail
  • heavy rain
  • surface wind gusts
  • bad visibility
168
Q

Thunderstorms are formed by a process called ______

A

Convection
- the transport of heat energy

169
Q

what is needed to produce a thunderstorm (needed for convection)

A
  • moisture
  • lift (upward development)
  • instability
170
Q

what is commonly experienced around thunderstorms

A

turbulence (often exceeding the performance capability of most aircraft)

171
Q

Gust front

A

line of dangerously gusty winds created on the leading edge of the advancing thunderstorm

172
Q

roll cloud

A
  • tube shaped
  • along gust front and frequently on the leading edge of thunderstorms, cold front, or line of squats
  • indicate shearing effects of different air masses
173
Q

wall clouds

A
  • abrupt lowering from a cumulonimbus cloud
  • mark lower portion of a very strong updraft
  • can proceed tornadoes if rotation is present
174
Q

Clouds that indicate low level wind shear, extreme turbulence, and occur in fast moving thunderstorms

A

roll and wall clouds

175
Q

Clouds that indicate low level wind shear, extreme turbulence, and occur in fast moving thunderstorms

A

roll and wall clouds

176
Q

Hail size that can cause significant damage to acft in a few seconds

A

larger than ½ to ¾ of an inch

177
Q

How is lightning formed

A
  • satiric charges
  • negative charge at the bottom and a positive charge at the top of the cloud
  • positive charge on the ground, eventually a circuit is created and a discharge takes place
178
Q

where do lightning strikes on aircraft commonly occur?

A

within 5,000 ft of the freezing level

179
Q

hail process

A

water is lifted by warm updraft, freezes, falls back down, then either repeats going up and down or continues down (can be yeeted out the tow of the cloud too)

180
Q

St. Elmo’s Fire

A

when enough static buildup causes a discharge (plasma) between an object and the air around it

181
Q

What hazards are associated with lightning?

A
  • structural damage
  • flash blindness
  • static build up
  • fuel ignition
182
Q

Roll and wall clouds indicate

A

a severe fast moving thunderstorm

183
Q

Tornado characteristics

A
  • up to 1 ½ miles wide
  • winds can reach up to 300
  • tornado itself can move 30-40 kts
184
Q

Most accurate means of tracking thunderstorms

A

NEXRAD (Next Generation Radar)

185
Q

What is a TVS

A

Tornado Vortex Signature

186
Q

Severe thunderstorms should be avoided by how many miles?

A

20

187
Q

If you have to penetrate a thunderstorms what should you adhere to?

A
  • penetrate perpendicular
  • penetrate below the freezing level
    or above -15 deg C level
  • Min altitude should be 4,000-6,000 AGL above highest terrain
188
Q

Be at least _____ feet higher than the top of the storm for every 10 knots of wind speed at the cloud top.

A

1000

189
Q

What is a microburst

A
  • sinking air formed by a thunderstorm
  • less than 2.5 miles in diameter
  • wind speeds as high as 150 mph
  • flow velocities can reach over 6,000 ft/min
190
Q

Development mechanisms of a microburst

A
  • Cooling beneath thunderstorm cloud base
  • sublimation
  • evaporation
  • existence of rain and/or hail
191
Q

Viable ways to recognize microburst conditions

A
  • Visual
  • Instrument
  • PIREPS
192
Q

Visual cues of a microburst (4)

A
  • Virga
  • localized blowing dust
  • shaft of rain
  • severe thunderstorms/cumulonimbus clouds
193
Q

Frequency of METAR observations

A

hourly, between 55 to 59 minutes past the hour

194
Q

Two sections of a METAR

A

Body and remarks

195
Q

When are SPECI’s issued

A

when critical data of a METAR observation has changed from the previous observation

196
Q

What does the “COR” in place of “AUTO” mean in the report modifier mean?

A

When a corrected METAR or SPECI is transmitted

197
Q

AO1 and AO2 meaning

A

equipment used to accomplish the observation
(precipitation sensitivity)

198
Q

Wind speeds on a METAR are displayed on a ___ min average

A

2 min

199
Q

When would you see RVR listed on the METAR

A
  • when prevailing visibility is less than or equal to 1 SM
    or
  • RVR for designated instrument runway is less than or equal to 6000 ft
200
Q

observation area METARS cover

A
  • 5 SM
  • “unless directed elsewhere for thunderstorms/lightning”
201
Q

Where can you look up remark codes for a METAR?

A

AFM 15-111

202
Q

Period of time a TAF covers

A
  • usually 30 hours (sometimes 24)
203
Q

The “best projection” of weather for your ETA +/- 1 HR

A

TAF

203
Q

The “best projection” of weather for your ETA +/- 1 HR

A

TAF

204
Q

Area that a TAF covers

A

5 SM

204
Q

Area that a TAF covers

A

5 SM

205
Q

When is VRB used in a TAF

A
  • wind speed is 6 KTS or less
  • not possible to forecast a single wind direction (thunderstorms)
206
Q

what does “9999” in a TAF mean?

A

7 SM visibility or greater is forecasted

207
Q

when are obstructions/weather conditions included in the visibility of a TAF

A

vis is forecasted to be 9000 meters or less