Ceiling
Ceiling is the height above ground level (AGL) of the lowest broken or overcast cloud layer, or the vertical visibility into an obscuration. A ceiling is the relevant meteorological parameter for determining VFR vs. IFR conditions and for applying approach minimums.
Sky Cover Terminology
- FEW (FEW): 1/8 to 2/8 cloud cover — not a ceiling
- SCT (Scattered): 3/8 to 4/8 cloud cover — not a ceiling
- BKN (Broken): 5/8 to 7/8 cloud cover — constitutes a ceiling
- OVC (Overcast): 8/8 cloud cover — constitutes a ceiling
- VV (Vertical Visibility): Reported when the sky is obscured; ceiling is the depth of the obscuration
Ceiling and VFR
Basic VFR weather minima in uncontrolled airspace at and above 1,000 ft AGL require: visibility ≥ 1 SM and clear of cloud. In controlled airspace below 10,000 ft, minima are: ceiling ≥ 1,000 ft, visibility ≥ 3 SM. Below 1,000 ft AGL in uncontrolled airspace, VFR flight is illegal when the ceiling is below 500 ft or visibility is below 2 SM.
On the TC Written Exam
Know that a ceiling is defined only by broken or overcast layers (not scattered or few). Know the VFR weather minima for different airspace classes. Know that an obscured sky reports ceiling as vertical visibility.
Related Terms
See also: Visibility, IMC, VMC.