A flight level (FL) is a standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the International standard pressure datum of 1013.25 hPa (29.92 inHg), the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.
Read more about Flight Level: Background, Transition Altitude, Quadrantal Rule, Semicircular/Hemispheric Rule, Reduced Vertical Separation Minima, Metric Flight Levels, Flight Levels in Russian Federation
Famous quotes containing the words flight and/or level:
“One man’s observation is another man’s closed book or flight of fancy.”
—Willard Van Orman Quine (b. 1908)
“For him nor deep nor hill there is,
But all’s one level plain he hunts for flowers.”
—Unknown. The Thousand and One Nights.
AWP. Anthology of World Poetry, An. Mark Van Doren, ed. (Rev. and enl. Ed., 1936)