FAA Airline Transport Pilot (ATM)Meteorology and Weather ServicesMedium
A pilot is planning a flight and wants to check for reports of severe icing not associated with thunderstorms along the route. Which product should be consulted for this specific hazard?
- AAIRMET Sierra
- BConvective SIGMET
- CAIRMET Zulu
- DSIGMET
Show answer & explanationAnswer & explanation
Correct answer: D. SIGMET
SIGMETs are issued for weather hazardous to all aircraft, including severe icing not associated with thunderstorms, severe or extreme turbulence, and widespread dust/sandstorms. AIRMET Zulu covers only moderate icing, a lesser threshold intended primarily for lighter aircraft.
Why the other options are wrong
- A. AIRMET Sierra covers IFR conditions and mountain obscuration, not icing.
- B. Convective SIGMETs address thunderstorm-related hazards, not icing specifically.
- C. AIRMET Zulu is for moderate icing, not severe icing.
SIGMET (Severe Icing)
A weather advisory issued for hazardous weather significant to all aircraft, including severe icing not associated with thunderstorms.
- Valid for 4 hours (6 for hurricanes)
- Covers severe icing, severe/extreme turbulence, dust/sandstorms, volcanic ash
- Distinct from AIRMET Zulu, which covers moderate icing
Memory trick: SIGMET = 'SIGnificant' hazard for every pilot, severe icing included.