SIGMETS are issued as a warning of weather conditions hazardous to which aircraft?

• A. All aircraft
• B. Commercial airliners only
• C. Private aircraft only
• D. Military aircraft only

Answer: (A)

SIGMETs warn of weather conditions hazardous to all aircraft. This means the advisory applies regardless of aircraft size or type, from private planes and sailplanes to airliners and military aircraft. The hazards covered include significant convective activity like strong thunderstorms, severe icing, severe turbulence, and dust or sand storms that can affect control, visibility, or performance. Because the dangers are universal to flight, pilots of any aircraft—whether flying commercially, privately, or for military purposes—should treat a SIGMET as a warning that applies to their flight. For less severe conditions, AIRMETs provide guidance, but SIGMETs indicate weather that could threaten flight safety for any aircraft.