When must an advisory be issued if the ILS critical area is not protected and a 'coupled', 'CAT III', 'autoland' approach will be conducted?

• A. Weather is clear with unlimited visibility
• B. Weather indicates ceiling 800 ft or more; or visibility 2 miles or more
• C. Autoland is engaged
• D. All pilots present must be informed beforehand

Answer: (B)

When an ILS critical area is not protected and a coupled CAT III autoland is planned, the advisory is required only when weather conditions allow other traffic to operate in the area. The threshold given—ceiling 800 ft or more, or visibility 2 miles or more—defines a minimum level of visibility and cloud cover where pilots could be in or near the approach path, making coordination important. In these conditions, issuing an advisory helps alert pilots to the unprotected critical area and reduce the risk of conflicts during the autoland.

If the weather is better than that (clear or very high ceilings and excellent visibility), or worse (lower than those minima), the advisory as described isn’t triggered by this rule. The other options don’t fit because they either describe the event itself (autoland engaged), imply a blanket rule about informing everyone (which isn’t the specific weather-based trigger), or suggest advisories are always issued regardless of weather, which isn’t what the standard specifies.