Which statement defines Instrument Meteorological Conditions (IMC)?

Which statement defines Instrument Meteorological Conditions (IMC)?

• A. Visibility less than 3 sm and ceilings less than 1000 ft, require pilots to fly primarily by instruments
• B. Visibility greater than 3 sm and ceilings greater than 1000 ft
• C. Visual flight rules
• D. Daylight only

Answer: (A)

IMC is when weather is not suitable for flying by looking outside, so pilots must rely on their instruments to fly. The statement captures the common defining scenario: visibility is below 3 statute miles and the cloud base (ceiling) is under 1,000 feet, which means pilots need to fly by instruments and follow instrument flight rules. In contrast, weather that meets or exceeds those visual minimums—visibility at least 3 miles and ceilings at least 1,000 feet—allows Visual Meteorological Conditions and VFR. IMC can occur in day or night, so daylight only isn’t a determinant.

IMC is when weather is not suitable for flying by looking outside, so pilots must rely on their instruments to fly. The statement captures the common defining scenario: visibility is below 3 statute miles and the cloud base (ceiling) is under 1,000 feet, which means pilots need to fly by instruments and follow instrument flight rules. In contrast, weather that meets or exceeds those visual minimums—visibility at least 3 miles and ceilings at least 1,000 feet—allows Visual Meteorological Conditions and VFR. IMC can occur in day or night, so daylight only isn’t a determinant.