Weather Flashcards
Approved wx briefing sources
- These are legal wx briefings because there is a record of a pilot getting these briefings and legally you have to get The wx before any IFR Flight.
- Flight service Station (FSS)
- 1800 wxbrief (phone)
- Wx brief (online)
- Foreflight (is legal but don’t say it for a stage check)
Standard wx briefing
A full briefing includes: adverse conditions, VFR not recommended, synopsis, current conditions, enroute forecast, destination forecast, winds aloft, NOTAMs, and ATC delays
Abbreviated wx briefing
Updates a previously received briefing or previously received Information from mass disseminated sources.
Outlook briefing
For departures 6 or more hours away. Includes forecasts for the time of the flight.
Inflight briefing
FSS also provides any of the above types in flight.
METARs
Routine aviation weather that shows surface weather observations. Scheduled METARs are published every hour. Non-scheduled METARs (SPECI) are issued when there is a significant change in one or more of the reported elements since the last scheduled METAR
Terminal aerodrome forecast (TAF)
- Weather forecast for 5 SM radius from the center of The runway complex.
- issued 4 times a day, every 6 hours and normally covers a 24 or 30 hour forecast period
- if an airport doesn’t have a TAF and you need to determine if you need an alternate use the GFA tool on aviationweather.gov
Airmets
- Valid for 6 hours, are the most generic, least severe, and are hazardous to all, but mostly smaller aircraft.
- three types of airmets: Sierra, tango, Zulu
Sierra airmet
For mountain obstructions (something that is obscuring the mountain so you cannot see them) or IFR conditions 1000 ft ceilings and 3SM visibility will trip off an IFR airmet).
Tango airmet
Turbulence; moderate turbulence and sustained surface winds o knots of or greater.
Zulu airmet
Moderate icing
Sigmets
Non-scheduled, as needed. Valid for 4 hours. And
- three types: sierra, tango, and Zulu
Sierra sigmet
Visibility is less than 3SM
- could be seen with sand dust Storms (in the desert)
Tango sigmet
Severe or extreme turbulence not associated with a thunderstorm. Clear Air turbulence (cat)
Zulu sigmet
Severe icing NOT associated with thunderstorms.
Convective sigmets
- issued hourly (55 minutes past the hour) valid for 2 hours. All imply severe turbulence, wind shear, icing, etc.
- used for: severe thunderstorms, tornadoes, and embedded thunderstorms.
Severe thunderstorm
Due to: surface winds greater than or equal to 50 knots and hail 3/4” inch or greater in diameter.
Embedded thunderstorms
- A line of thunderstorms at least 60 miles long affecting at least 40% of its length.
- thunderstorms producing heavy precipitation effecting 40% of at least 3,000 square miles.
Pirep
A pilot report on conditions
What 2 things are required for icing to form?
- Visible moisture
- Aircraft surface temperature below freezing
3 types of icing
Structural icing, induction icing, and instrument icing
Structural icing
Accumulation of ice on the exterior of The aircraft. Small/narrow objects are The best collectors of droplets and ice. Ice on the temperature probe or pitot tube are the first places a pilot will see indications of ice accumulations.
Induction icing
Reduces the amount of air available for combustion within the cylinders. Most Common type is carburetor ice, but we don’t have a carburetor. Fuel injected systems can still be effected if the engines air source becomes blocked.
Instrument icing
Pitot-static system becomes blocked affecting the Flight instruments.
3 types of structural icing
Clear ice, rime ice, and mixed ice
Clear ice
Formed by The slow freezing of supercooled water. Dan The most serious form because it leaks back and changes the camber for the wing, can freeze control surfaces, and it is very heavy. Happens between +2°C and -10°C. Occurs downflow of the point of initial contact. Clear ice freezes over the center of the airfoil and not just The leading edge because it freezes at higher temperatures, it has that time to move over the airfoil.
Rime Ice
A rough, milky, opaque ice that is formed by The instantaneous or rapid freezing of droplets as they strike the aircraft. Happens at -15°C and lower. Occurs upflow of the point of the initial contact. Rime ice freezes on impact.
Mixed Ice
A combination of clear and rime ice formed on the same surface. Occurs between -15°C and -10°C. Occurs both up flow and down flow of the airframe.