CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER I-A—MOBILE OFFSHORE DRILLING UNITS (parts 107 to 109) > PART 108—DESIGN AND EQUIPMENT > SUBPART B—Construction and Arrangement (§108.113 to §108.241) > 108.233—Location and size.

108.233—Location and size.

(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 9/10 the overall length of the helicopter, and a width of 3/4 of the overall length of the helicopter.

Code of Federal Regulations

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.