Which event is listed as a mandatory ATC report?

• A. Outer marker
• B. Final approach (inside radar)
• C. Unforecast weather
• D. Radio/nav issue

Answer: (C)

The event being tested is weather reporting requirements to ATC. Unforecast weather is something a pilot must report to ATC because it directly affects safety and how the airspace is managed. If actual weather differs from what was forecast or deteriorates, informing ATC promptly helps controllers adjust routing, separation, and advisories for other flights. This communication keeps everyone safer by sharing real-time conditions that could impact altitudes, headings, and approach decisions.

Passing an outer marker or reporting final approach within radar are routine navigation milestones that aren’t, by themselves, mandated ATC weather reports. A radio or navigation equipment issue triggers different procedures (such as following lost-comms or equipment failure protocols) but isn’t categorized as a standard weather-report requirement.