1. (a) Each helicopter deck must be—

   1. (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. (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.
2. (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.

Note: For the purpose of paragraph (a)(2) the overall length is measured across both main rotors in the fore and aft line.