FAA AIRCRAFT DISPATCHER ACTUAL EXAM 400 QUESTIONS AND CORRECT ANSWERS 2023-2024 UPDATE WITH EXPERT FEEDBACK |NEW!! What is a Radar summary chart? - ANSWER- A radar summary chart is a graphically depicted collection of radar weather reports. Does the Radar summary chart depict forecast conditions, or observed conditions? How often? - ANSWER- Observed, hourly. What is the difference between visible and infrared Satellite imagery? - ANSWER- The visible images display cloud cover. The infrared images display the earth in a manner that correlates with temperature. Generally speaking, the warmer an object, the more infrared energy it emits. What does water vapor imagery show on the Satellite imagery? - ANSWER- The water vapor images display the earth in a manner that correlates to quantity of water vapor in the upper portions of the atmosphere (25,000 feet and higher in general). The most useful information to be gained from the water vapor images is the locations of storm systems and the jet stream. What do the Valid Times indicate? (on a prog chart) - ANSWER- 12 and 24 hours. They indicate that the prog chart is valid for 12 hours from the time issued, or 24 hours from the time issued. How many times are Prog charts issued? - ANSWER- 4 times a day. 00Z, 06Z, 12Z, 18Z. Is a prog chart a forecast or a depiction of actual conditions? - ANSWER- Forecast. Remember "to prognosticate" means "to forecast" What kinds of weather/hazards are shown on the low level prog chart? - ANSWERPrecip, icing, turbulence, thunderstorms, tropical storms, hurricanes IFR/MVFR conditions, areas of high/low pressure, different types of fronts. What is a cold front? - ANSWER- The leading edge of an advancing cold air mass What clouds are associated with a cold front? - ANSWER- Cumulus and cumulonimbus What weather is associated with a cold front? - ANSWER- Thunderstorms, hail, tornadoes, good visibility. What discontinuities are associated with a cold front? - ANSWER- -Temp: Cold air advances and overtakes warm air. -Pressure: Pressure will drop then rises abruptly after the front passes. - Windshift What is a warm front? - ANSWER- The leading edge of an advancing warm air mass. What clouds are associated with a warm front? - ANSWER- Stratus clouds. Nimbostratus, altostratus, cirrostratus, cirrus. What type of weather is associated with a warm front? - ANSWER- Continuous rain, Drizzles, poor visibility. What type of weather is associated with a stationary front? - ANSWER- Several days of overcast weather (stratus clouds) and drizzle, nothing severe. What type of front is associated with a temperature inversion? - ANSWER- An occluded front. This is because the advancing cold airmass sinks below the warm airmass and pushes the warm airmass up above the cold airmass. This creates an inversion because the warm air will be above the cold airmass and therefore temperature will increase as altitude increases. What is a temperature inversion? - ANSWER- A temperature inversion is when temperature increase with altitude rather than decrease with altitude. Inversions are common in the stratosphere. What is an airmass? - ANSWER- a volume of air defined by its temperature and water vapor content. Air masses cover many hundreds or thousands of square miles, and adapt to the characteristics of the surface below them. They are classified according to latitude and their continental or maritime source regions. What weather is associated with a warm front? - ANSWER- continuous rain and drizzle What discontinuities are associated with a warm front? - ANSWER- -Temp: Warm air -Pressure: Pressure usually drops abruptly. What is an occluded front? - ANSWER- an occluded front is a front that is made up of 3 air masses. 2 cold air masses (cold and cool), and one warm air mass. All the air masses are all moving in the same direction. How and why does a temperature inversion occur in an occluded front? - ANSWER- A temperature inversion occurs in an occluded front because the cold air masses push the warm air mass up and above them, therefore warmer air will exist as altitude increases. What is a stationary front? - ANSWER- A stationary front is when an advancing warm airmass and an advancing cold airmass converge and one is not strong enough to overtake the other so the air masses become stationary. What is an Isobar? - ANSWER- An Isobar is a line of equal pressure reduced to sea level. Since pressure varies with altitude, we cannot readily compare station pressures between stations at different altitudes. To make them compatible with each other, we must adjust them to a common level (MSL) What is standard sea level pressure in -millibars -inches of mercury -millimeters of mercury -PSI - ANSWER- 1013.2 -millibars 29.92 -inches of mercury 14.7-PSI 760 -millimeters of mercury Where to find approved WX sources? - ANSWER- Ops specs. What is a strong pressure gradient (closely spaced isobars) indicate? - ANSWER- High winds What is Pressure Altitude? - ANSWER- For pressure altitude, set the window in your altimeter to 29.92. Whatever value it reads is pressure altitude. What is Density Altitude? - ANSWER- pressure altitude corrected for non-standard temperature. What is true altitude? - ANSWER- This is the height above "mean sea level" What is absolute altitude? - ANSWER- Absolute altitude is your height above the ground. Describe circulations associated with high pressure systems. - ANSWER- High pressure = clockwise circulations (Anti-cyclones) Describe circulations associated with low pressure systems. - ANSWER- Low pressure = counter-clockwise circulations (Cyclones) How often are SIGMETs and AIRMETs issued? - ANSWER- AIRMETs: Scheduled - every 6 hours starting at 0145Z Max Forecast period - 6 hours SIGMETs: Unscheduled - as needed Max Forecast period - 4 hours Once issued, how long are SIGMETs good for? - ANSWER- 4 hours