Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Instrument Rating > Weather > Flashcards

Weather Flashcards

1
Q

Air Stability

A

Ability of atmosphere to resist vertical motion. Measured by the difference between the temperature lapse rate of a given parcel of air, compared to the dry adiabatic lapse rate (3c per 1000). Dry/cool air is more stable. Inversions also help.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Turbulence procedures

A
  • slow to Va (or slower)
  • maintain level flight, while accepting changes in airspeed or altitude
  • exit the situation however practicable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Wind shear/microburst procedures

A
  • detection: sudden unexplained changes in airspeed or VSI
  • be prepared to respond to the opposite effect
  • exit the area, make a report
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Structural icing procedures

A
  • react quickly. Even a sandpaper amount of ice can reduce lift by 30% and increase drag by 40%. And it can accumulate as much as 3 inches in 5 minutes.
  • notify ATC (possibly with urgency) and get an amended clearance: different altitude (out of freezing level), or different route (out of precip)
  • report the PIREP
  • expect a significantly higher stall speed on landing
  • never take off with frost on the plane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Jet stream speed

A

50kts or greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Tropopause height

A

Ranges from 20,000 at the poles to 65,000 at the equator. Average is 37,000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tropopause defined by

A

Sharp change in the temperature lapse rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Standard temperature and lapse rate

A

15c at sea level. Decreases 2c per 1000ft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Air circulation direction (northern hemisphere)

A

High pressure: clockwise

Low pressure: counterclockwise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Causes of wind deflection

A

Near the ground (<2000agl): friction causes it to move toward the lower pressure. Contours also affect.

In the air: coriolis force deflects at a right angle (northern hemisphere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Increased precipitation comes from

A

Upward currents. Cloud particles collide and merge faster, creating more precip and bigger drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ice pellets on the surface always indicates

A

Freezing rain at a higher level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Standing Lenticular clouds

A

Lens shaped clouds that form on the crests of air rotating near mountains. Indicator of strong turbulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cloud families

A

High, mid, low, and “clouds with extensive vertical development”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fair weather cumulus clouds indicate

A

Bumpy turbulence beneath the cloud, but good visibility. The top of the cloud is the upper limit of convection, meaning smooth air above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fog types

A

Radiation: cold ground cools the air to its dew point

Advection (sea) fog: moist air is blown over cooler land or water

Upslope: moist air is blown up a slope and cooled to its dew point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Thunderstorm ingredients

A

Moisture, Lift, and Unstable air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Thunderstorm stages

A

Cumulus: rising air. Continuous updrafts and lowering pressure

Mature: precipitation begins, as do downdrafts. High intensity.

Dissipating: mostly downdrafts

19
Q

Squall lines - what, and where?

A

Narrow band of active thunderstorms. Winds of at least 16kts rising to 22kts for 1+ minute. Usually forms ahead of a cold front, but CAN develop in unstable air anywhere

20
Q

Inadvertent Thunderstorm penetration procedures

A
  1. Keep your eyes on your instruments
  2. Maintain reduced airspeed
  3. Fly straight through
  4. Maintain attitude, but dont force altitude
21
Q

Microburst duration & strength.

A

Rarely longer than 15 mins. However, there may be multiple microbursts in an area. Downdrafts as strong as 6000 fpm, horizontal winds as strong as 45kts each way (90 total shear)

22
Q

Conditions for frost

A

Freezing air at the surface that is also below the dew point

23
Q

Conditions that produce the highest levels of accumulation of structural icing

A

Large supercooled water droplets (AKA Freezing rain)

24
Q

What is one good thing freezing rain indicates?

A

There must be a layer above of warmer air in order for supercooled droplets to form

25
Q

Effect of snow or frost with the roughness of coarse sandpaper

A

Reduces lift by as much as 30% and drag by as much as 40%

26
Q

Procedure: landing with ice build up

A

Land at a higher speed, with minimum large/abrupt configuration changes, and minimum flaps, to account for

  • decreased thrust (from lift and drag) and
  • the possibility of a tailplane/empennage stall (due to ice building up undetected on the horizontal stabilizer)
27
Q

Procedure: encountering ice in flight

A

Leave the area of precipitation and/or change to a warmer OR much colder (-10c) altitude (either may be higher or lower), disable autopilot

28
Q

Indicators of impending tailplane stall

A

Elevator control pulsing, oscillation/vibration, abnormal nose-down trim change, reduction in elevator effectiveness, sudden change in elevator force, uncommanded nose-down pitch

29
Q

Procedure: suspected tailplane ice

A

Retract flaps, nose up, add power, operate de-icing equipment several times, and make nose-down pitch changes cautiously

30
Q

Procedure: roll upset (due to icing)

A

Increase airspeed, extend flaps to first setting, operate de-icing systems

31
Q

Risks of climbing out in icing conditions

A

Ice may develop on the underside and farther back than in cruise flight and therefore go undetected. Use of autopilot, especially VS mode highly discouraged

32
Q

Icing: first place to form

A

Small protuberances and the tailplane

33
Q

Typical wind shear location

A

LLWS: Strong temperature inversions, on all sides (up to 15 miles) or below a thunderstorm cell, near frontal activity

WS: any change in wind, esp up to 6 hours ahead of a warm front (<5000agl) , 3 hours behind a cold front >5000agl)

34
Q

TAF Validity

A

5 mile radius of the center of an airport’s runway complex during a 24 hour period

35
Q

PIREP (UA) Components

A 
OV over location
TM time
FL altitude
TP aircraft type
SK sky cover
WX weather and visibility
TA temperature
WV wind
TB turbulence
IC icing
RM remarks
36
Q

Winds/temperatures aloft format

A

DDffTT
Direction (2 digit DD)
Velocity (ff)
Temperature (TT)

Winds light and variable are coded 9900

Direction greater than 50 = subtract 50 and add 100 to wind

Direction above 50 and wind greater than 99 = “more than 200 knots”

For altitudes greater than 24000, temperatures are always negative, so the sign is omitted

37
Q

Wind aloft reports and forecasts given in what units and relative to what direction?

A

Knots, True North

38
Q

Winds and temperatures aloft are forcast starting at what altitude above a station?

A 
Temp = 2500+
Wind = 1500+
39
Q

In flight weather advisory types

A

AIRMET: conditions significant to single engine/light aircraft (surface winds of 30+, wide spread IFR conditions, mountain obscurement, etc)

SIGMET: conditions significant to all aircraft (eg severe icing, dust storms, volcanic ash)

Convective SIGMETS: Thunderstorms, tornadoes, LLWS

AWW: severe weather forecasts

CWA: Center weather advisories

AIRMET/SIGMET broadcast on HIWAS at H+15 and H+45
Convective SIGMETS (WST) broadcast at H+15, 30, 45, and 55)
40
Q

Report type AC

A

Convective outlook. Describes prospects for general thunderstorm activity for following 24 hours. Can be Slight, Moderate, or High.

41
Q

Shown on a constant pressure chart

A

Temperature, dewpoint, wind, height, and height changes (12 hours)

42
Q

Significant Weather (SIGWX) charts

A

Presents weather information that may impact flight planning. Comes in low level (FL240 and below) and high level (FL250-FL630) forecasts.

Low level: turbulence, freezing levels. Issued 4x daily.

High level: turbulence, cumulonimbus clouds, tropopause height, jet streams

43
Q

SIGWX Jet Stream Pennants

A

50kts

44
Q

Jet stream seasonality

A

Weaker and farther north in the summer, stronger and further south in the winter

Instrument Rating (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions