Controllers must advise pilots of hazardous weather contained in HIWAS broadcasts that may impact operations within how many nautical miles of their sector?

• A. 25 NM
• B. 50 NM
• C. 100 NM
• D. 150 NM

Answer: (D)

The main idea here is that HIWAS provides continuous hazardous weather information that can affect flight operations, and controllers have a duty to ensure pilots are aware of any weather in that broadcast which could impact their sector’s area. The distance used for this advisory is 150 nautical miles. This radius gives enough lead time for pilots to plan or adjust routes, holds, or diversions before entering or while operating near affected airspace, especially on en route segments and during approaches.

HIWAS includes alerts such as SIGMETs, convective SIGMETs, and AIRMETs that describe significant weather like strong turbulence, icing, icing, thunderstorms, or volcanic ash. By advising within 150 NM, controllers help pilots incorporate the weather information into their flight planning and decisions. Distances smaller than 150 NM wouldn’t reliably cover surrounding routes and sectors where hazardous weather could still influence operations, which is why the 150 NM figure is the standard.