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:
“When we are high and airy hundreds say
That if we hold that flight they’ll leave the place,
While those same hundreds mock another day
Because we have made our art of common things ...”
—William Butler Yeats (1865–1939)
“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)