Definition
An area beyond the runway, centered on the extended runway centerline, that is under the control of airport authorities and is selected or prepared as a suitable area over which an airplane may make a portion of its initial climb to a specified height. For turbine-powered transport category airplanes certificated after September 30, 1958, the clearway plane extends from the end of the runway with an upward slope not exceeding 1.25 percent, with no protruding obstacles, and a minimum width as specified in regulations.
Plain English
A clear, obstacle-free area off the end of the runway that an airplane can climb over during the first part of its takeoff. It is not part of the runway itself, but it is officially recognized as safe to climb across, so it can be counted when figuring out how much room the airplane has to get airborne.
Context Anchor
Seen in runway information, airport design data, and takeoff distance planning.
Derivation
Clearway is literally a 'cleared way' -- a path kept free of obstacles. The 'way' refers to the path of flight, not a surface to roll on. Knowing this helps separate it from a runway or stopway, which are surfaces the aircraft physically touches.
Why Pilots Care
It extends the effective takeoff distance available and directly affects how much weight an aircraft can safely carry on departure from that runway.
Intuition Check
Do not read clearway as “a clear taxi path” or “extra runway.” It means a specified obstruction-free area beyond the takeoff end, mainly for the airplane’s first part of climb.
Example Sentence 1
With a 500-foot clearway beyond the runway, the crew was able to use the longer Takeoff Distance Available when calculating their maximum takeoff weight.
Example Sentence 2
Airport maintenance crews regularly inspect the clearway to ensure no new obstacles have appeared.