46 C.F.R. § 108.241 Visual aids.
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(a) Each helicopter deck must— (1) Have a wind direction indicator located in an unobstructed area readily visible to helicopter pilots approaching the deck; (2) Be fitted around the perimeter with yellow and blue lights in alternate order, not more than 3 meters (10 ft.) apart; and (3) Be marked with— (i) The unit's identification; (ii) A continuous line 40 centimeters (16 in.) wide on the perimeter; and (iii) Aiming circles as may be appropriate considering deck configuration, helicopter type, and operational requirements. (b) All markings must be in a contrasting color to the surface of the deck.
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PART 108—DESIGN AND EQUIPMENT
Subpart B—Construction and Arrangement
Helicopter Facilities
§ 108.241 Visual aids.

