What is a cloud ceiling?

What is a cloud ceiling?

• A. The Base of the Lowest Cloud Layer Above Ground
• B. The Altitude at Which Clouds Begin Forming
• C. The Height of the Lowest Layer Above Ground That Covers the Sky
• D. The Height of the Lowest Layer of Clouds That Covers the Sky, Limiting VFR Visibility

Answer: (D)

Ceiling in aviation is the height of the lowest cloud layer that covers more than half the sky and therefore limits visual flight rules (VFR) visibility. The best choice captures both the fact that it’s the lowest obscuring layer and that it affects whether a pilot can fly VFR. If the lowest broken or overcast layer starts at a certain height, that height is the ceiling and it signals the weather minimums for VFR operations. The other descriptions miss either the requirement that the layer actually covers the sky, or the operational significance of how that coverage limits visibility for flight rules.

Ceiling in aviation is the height of the lowest cloud layer that covers more than half the sky and therefore limits visual flight rules (VFR) visibility. The best choice captures both the fact that it’s the lowest obscuring layer and that it affects whether a pilot can fly VFR. If the lowest broken or overcast layer starts at a certain height, that height is the ceiling and it signals the weather minimums for VFR operations. The other descriptions miss either the requirement that the layer actually covers the sky, or the operational significance of how that coverage limits visibility for flight rules.