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A tower shape with heights above ground and above sea level.
Also known as: Tower symbol chart, Mast marking
An obstruction on an aeronautical chart carries two heights: above mean sea level in large figures and above ground level in brackets. The bracketed figure is what tells a pilot how far the structure rises from the terrain beneath it.
Marks a tall structure hazardous to flight, drawn as a small tower shape with two height figures.
Contexts: Navigation, Maps
Gives height above mean sea level and, in brackets, above ground level, the second being what states how far the structure projects from its terrain.
Contexts: Navigation, Maps
Is drawn differently above a threshold height and carries an added marking where the obstruction is lit.
Contexts: Navigation, Maps
A narrow tapering tower outline with a small base, beside two numerals one of which is bracketed.