46 C.F.R. § 108.233 Location and size.
Title 46 - Shipping
(a) Each helicopter deck must be— (1) At least the size of the rotor diameter of the largest single main rotor helicopter that will be used on the facility; or (2) If tandem main rotor helicopters use the facility, at least of a size to provide a longitudinal axis of Note: For the purpose of paragraph (a)(2) the overall length is measured across both main rotors in the fore and aft line. (b) Each helicopter deck must be located so as to provide clear approach/departure paths to enable the largest helicopter using the facility to operate in all weather conditions which allow helicopter operations.
Title 46: Shipping
PART 108—DESIGN AND EQUIPMENT
Subpart B—Construction and Arrangement
Helicopter Facilities
§ 108.233 Location and size.

