Technology / Aviation / Flight Level (FL): A level of constant atmospheric pressure related to a reference datum of 29.92 inches of mercury. Each is stated in three digits that represent hundreds of feet?€”flight level 250 represents a barometric altimeter indication of 25,000', flight level 255 as 25,500'.
Search Google for Flight Level (FL):
Flight Noun Synonyms: flying, soaring, winging, excursion
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Level Adjective Synonyms: even, smooth, plane, uniform, plain, flat, flush, straight, true
Level Noun Synonyms: horizontal, prone, supine
Level Verb Synonyms: aim, point, draw a bead, direct, train, focus
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Science / Weather / Mean Sea Level: The average height of the sea surface water level. For the United States, it is computed by averaging the levels of all tide stages over a nineteen year period, determined from hourly height readings MORE
Science / Tides and Currents / Mean River Level: A tidal datum. The average height of the surface of a tidal river at any point for all stages of the tide observed over the National Tidal Datum Epoch. It is usually determined from hourly height read MORE
Science / Tides and Currents / Mean Diurnal Tide Level (MDTL): A tidal datum. The arithmetic mean of mean higher high water and mean lower low water. MORE
Science / Weather / Marginal Visual Flight Rules (MVFR): Refers to the general weather conditions pilots can expect at the surface. MVFR means Minimum or Marginal Visual Flight Rules. MVFR criteria means a ceiling between 1,000 and 3,000 feet and/or 3 to 5 MORE
Technology / Aviation / Mean Sea Level (MSL): The average height of the surface of the sea for all stages of tide: used as a reference for elevations, and differentiated from AGL. MORE
Science / Tides and Currents / Mean Tide Level (MTL): A tidal datum. The arithmetic mean of mean high water and mean low water. Same as half-tide level. MORE