Also known as: fl.
FL has various meanings in the Aviation category. Discover the full forms, definitions, and usage contexts of FL in Aviation.
Altitude at barometric setting of 1013.2 millibars or 29.92 inches of mercury, expressed in rounds hundreds of feet. This is usual mostly above 18,000 feet. FL350 is 35,000 feet.
AviationHazardous cargo. Flammable liquids are those that give off vapours which become spontaneously combustible at certain temperatures (flash point); these are often referred to as "inflammable" but "flammable" is preferred.
AviationThe freezing level, or 0 °C (zero–degree) isotherm, represents the altitude in which the temperature is at 0 °C (the freezing point of water) in a free atmosphere (ie allowing reflection of the sun by snow, etc). Any given measure is valid for only a short period of time, often less than a day.
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