FAA Sport Pilot Airplane (SPA)WeatherMedium
During a preflight briefing, a pilot is advised that a SIGMET has been issued for severe turbulence along the planned route. Compared to an AIRMET, a SIGMET is issued for weather conditions that are
- APotentially hazardous to all categories of aircraft, such as severe turbulence, severe icing, and widespread dust storms
- BPrimarily hazardous to light aircraft, such as moderate turbulence and marginal VFR ceilings
- CRoutine advisories issued only for scheduled air carrier flight planning
- DLimited to convective activity affecting only Class B airspace
Show answer & explanationAnswer & explanation
Correct answer: A. Potentially hazardous to all categories of aircraft, such as severe turbulence, severe icing, and widespread dust storms
A SIGMET (Significant Meteorological Information) warns of weather hazardous to all aircraft, including severe turbulence, severe icing, and widespread dust or sandstorms, while an AIRMET covers conditions primarily hazardous to light aircraft.
Why the other options are wrong
- B. This describes an AIRMET, not a SIGMET.
- C. SIGMETs are issued for all pilots, not just air carriers, when hazards exist.
- D. SIGMETs are not restricted to Class B airspace or convective activity only.
SIGMET vs AIRMET
SIGMETs warn of weather hazardous to all aircraft (severe icing, turbulence, dust storms); AIRMETs warn of weather hazardous primarily to light aircraft.
- SIGMET: severe turbulence, severe icing, dust/sandstorms, volcanic ash
- AIRMET Sierra: IFR/mountain obscuration
- AIRMET Tango: moderate turbulence/strong winds
- AIRMET Zulu: moderate icing/freezing level
Memory trick: SIGMET = 'Significant for everyone'; AIRMET = 'Advisory for light craft'.