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:
“Here I am.... You get the parts of me you like and also the parts that make you uncomfortable. You have to understand that other people’s comfort is no longer my job. I am no longer a flight attendant.”
—Patricia Ireland (b. 1935)
“There are old heads in the world who cannot help me by their example or advice to live worthily and satisfactorily to myself; but I believe that it is in my power to elevate myself this very hour above the common level of my life.”
—Henry David Thoreau (1817–1862)