AS 121 EXAM 4 QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2025/2026
What time frame does the GFA report? - Answers 14 hours in the past until 15 hours in the
future
What purpose does the GFA (Graphical Forecast for Aviation) serve? - Answers Provide
necessary weather information to give users a complete picture of the weather that may affect
a flight in the continental United States (CONUS)
Which of the following is a non-convective inflight weather advisory that is considered
potentially hazardous to all aircraft? - Answers SIGMET
Which of the following are aviation forecasts depicted on the GFA? - Answers TAFs,
thunderstorms and turbulence
Weather data derived from AWOS observations will contain what prefix? - Answers AUTO
Which of the following is the AIRMET code used to denote IFR and mountain obscuration? -
Answers Sierra
What weather data does an AWOS-2 system report? - Answers The information provided by an
AWOS-1 plus visibility
Which of the following is the AIRMET code used to denote strong surface winds? - Answers
Tango
Which of the following is an inflight weather advisory that is considered potentially hazardous to
light aircraft? - Answers AIRMET
Which of the following would cause the issuance of a convective SIGMET? - Answers Severe
thunderstorms with surface winds greater than 50 knots
The most severe type of low-level wind shear (microburst) is associated with what kind of
weather? - Answers Convective precipitation
Why does the wind direction at the surface vary from the wind direction at 2000 feet? - Answers
Friction
What happens to barometric pressure as altitude increases? - Answers Pressure decreases
The vast majority of clouds, weather, storms and temperature variances occur within - Answers
The troposphere
The troposphere - Answers Uneven heating of the Earth's surface
Which way does air flow? - Answers From high pressure to low pressure
What is standard sea level pressure and temperature in the International Standard Atmosphere
, (ISA)? - Answers 29.92 "Hg and 59 degrees F
Which way does air circulate around a high pressure area (Northern Hemisphere) - Answers
Clockwise
The average temperature decrease within the troposphere is - Answers 2 degrees Celsius every
1000 feet of altitude
Falling pressure generally indicates what kind of weather? - Answers Approaching bad weather
A pilot can expect the following when encountering wind shear that produces a change in wind
direction from a headwind to a tailwind. - Answers A decrease in airspeed and performance
Which way does Coriolis force deflect moving air in the Northern hemisphere? - Answers To the
right
Which of the following produces a "sea breeze"? - Answers Warm air over land rises, cool air
over water descends causing air to move from over the water toward the shore
What effect does altitude have on takeoff distance in an airplane? - Answers The higher the
altitude the longer the takeoff run
Convective circulation patterns associated with sea breezes are caused by - Answers cool,
dense air moving inland from over the water.
The wind at 5,000 feet AGL is southwesterly while the surface wind is southerly. This difference
in direction is primarily due to - Answers friction between the wind and the surface.
What causes variations in altimeter settings between weather reporting points? - Answers
Unequal heating of the Earth's surface.
The development of thermals depends upon - Answers solar heating
Every physical process of weather is accompanied by, or is the result of, a - Answers heat
exchange.
What is an isobar? - Answers A line of equal barometric pressure drawn on a chart
What is "dew point"? - Answers The temperature at which air can hold no more moisture
What is the height of a cloud base if the temperature at the ground is 95 degrees F and the dew
point is 85 degrees F? - Answers Approximately 2,270 feet
What happens when moist, unstable air rise to a point where temperature and dew point are the
same? - Answers Clouds often form
Which of the following defines "occluded front"? - Answers A fast moving cold front catches up
to a slow moving warm front
What time frame does the GFA report? - Answers 14 hours in the past until 15 hours in the
future
What purpose does the GFA (Graphical Forecast for Aviation) serve? - Answers Provide
necessary weather information to give users a complete picture of the weather that may affect
a flight in the continental United States (CONUS)
Which of the following is a non-convective inflight weather advisory that is considered
potentially hazardous to all aircraft? - Answers SIGMET
Which of the following are aviation forecasts depicted on the GFA? - Answers TAFs,
thunderstorms and turbulence
Weather data derived from AWOS observations will contain what prefix? - Answers AUTO
Which of the following is the AIRMET code used to denote IFR and mountain obscuration? -
Answers Sierra
What weather data does an AWOS-2 system report? - Answers The information provided by an
AWOS-1 plus visibility
Which of the following is the AIRMET code used to denote strong surface winds? - Answers
Tango
Which of the following is an inflight weather advisory that is considered potentially hazardous to
light aircraft? - Answers AIRMET
Which of the following would cause the issuance of a convective SIGMET? - Answers Severe
thunderstorms with surface winds greater than 50 knots
The most severe type of low-level wind shear (microburst) is associated with what kind of
weather? - Answers Convective precipitation
Why does the wind direction at the surface vary from the wind direction at 2000 feet? - Answers
Friction
What happens to barometric pressure as altitude increases? - Answers Pressure decreases
The vast majority of clouds, weather, storms and temperature variances occur within - Answers
The troposphere
The troposphere - Answers Uneven heating of the Earth's surface
Which way does air flow? - Answers From high pressure to low pressure
What is standard sea level pressure and temperature in the International Standard Atmosphere
, (ISA)? - Answers 29.92 "Hg and 59 degrees F
Which way does air circulate around a high pressure area (Northern Hemisphere) - Answers
Clockwise
The average temperature decrease within the troposphere is - Answers 2 degrees Celsius every
1000 feet of altitude
Falling pressure generally indicates what kind of weather? - Answers Approaching bad weather
A pilot can expect the following when encountering wind shear that produces a change in wind
direction from a headwind to a tailwind. - Answers A decrease in airspeed and performance
Which way does Coriolis force deflect moving air in the Northern hemisphere? - Answers To the
right
Which of the following produces a "sea breeze"? - Answers Warm air over land rises, cool air
over water descends causing air to move from over the water toward the shore
What effect does altitude have on takeoff distance in an airplane? - Answers The higher the
altitude the longer the takeoff run
Convective circulation patterns associated with sea breezes are caused by - Answers cool,
dense air moving inland from over the water.
The wind at 5,000 feet AGL is southwesterly while the surface wind is southerly. This difference
in direction is primarily due to - Answers friction between the wind and the surface.
What causes variations in altimeter settings between weather reporting points? - Answers
Unequal heating of the Earth's surface.
The development of thermals depends upon - Answers solar heating
Every physical process of weather is accompanied by, or is the result of, a - Answers heat
exchange.
What is an isobar? - Answers A line of equal barometric pressure drawn on a chart
What is "dew point"? - Answers The temperature at which air can hold no more moisture
What is the height of a cloud base if the temperature at the ground is 95 degrees F and the dew
point is 85 degrees F? - Answers Approximately 2,270 feet
What happens when moist, unstable air rise to a point where temperature and dew point are the
same? - Answers Clouds often form
Which of the following defines "occluded front"? - Answers A fast moving cold front catches up
to a slow moving warm front
