ICAO heliport manual 5.2.2.10
Desciption
Air Transit Route Markers are made from aluminum with two frangible poles, baseplates, anchor rope.
The panel is nonilluminated and it is colored with 3M foils.
Where air transit routes are established their center lines should be marked with markers
The markers shall be frangible and located along the centerline of the air transit route
The markers shall be spaced at intervals of not more than 60 m on straight sections and 15 m on curves
The surface of the marker as viewed by a pilot shall be a rectangle with a height to width radio of approximately 1 to 3 and have a minimum area of 1.500 cm2
The marker shall show three vertical bands colored yellow, green and yellow respectively and shall not exceed 1 m above ground or snow level