How is the term “Ceiling” defined in aviation?

The term “Ceiling” in aviation is defined as the height above the Earth’s surface of the lowest layer of clouds or obscuring phenomena that is reported as broken, overcast, or obscured, or when the visibility is reduced due to weather. This is critical for pilots as it determines the lowest altitude at which they can operate under Visual Flight Rules (VFR) and how much vertical space they have in the cloud layers or when flying in restricted visibility. Understanding the ceiling is essential for safe navigation and ensuring that pilot and aircraft remain within regulatory guidelines.

The other definitions provided in the choices, while related to aviation, do not accurately represent the specific definition of ceiling in this context. For example, the height of the highest point of the aircraft relates more to the aircraft's altitude rather than a meteorological term. Similarly, the altitude required during Instrument Flight Rules and the vertical limit of airspace pertain to operational regulations and airspace structure rather than the physical definition of ceiling pertaining to weather conditions.