Definition
The minimum horizontal and vertical distances a VFR aircraft must maintain from clouds, as specified in 14 CFR Part 91.155. The required distances vary by airspace class and altitude, and are intended to ensure that VFR pilots can see and avoid IFR traffic that may emerge from clouds.
Plain English
Rules that tell a VFR pilot how far they must stay from any cloud — both sideways and up or down — depending on the airspace and altitude they are flying in.
Context Anchor
Seen in VFR-on-top operations, where an IFR flight is allowed to fly in visual conditions above a cloud layer but must still meet the visual cloud-clearance rules.
Derivation
Criteria comes from a Greek word meaning a standard used for judging. That helps here because these are not rough guidelines; they are the standards used to decide whether the flight conditions are legally visual.
Why Pilots Care
Ensures the flight remains in visual meteorological conditions relative to clouds while on top, maintaining legality and safety margins.
Intuition Check
Do not read this as “stay a comfortable distance from clouds.” It means specific required spacing from clouds, based on the airspace and altitude you are flying in.
Example Sentence 1
Before climbing through the gap, the pilot checked the distance-from-cloud criteria for Class E airspace below 10,000 feet.
Example Sentence 2
Maintaining the distance-from-cloud criteria allowed the flight to continue legally above the cloud deck.