135.609 VFR ceiling and visibility requirements for Class G airspace.
(a) Unless otherwise specified in the certificate holder's operations specifications, when conducting VFR helicopter air ambulance operations in Class G airspace, the weather minimums in the following table apply:
(b) A certificate holder may designate local flying areas in a manner acceptable to the Administrator, that must -
(1) Not exceed 50 nautical miles in any direction from each designated location;
(2) Take into account obstacles and terrain features that are easily identifiable by the pilot in command and from which the pilot in command may visually determine a position; and
(3) Take into account the operating environment and capabilities of the certificate holder's helicopters.
(c) A pilot must demonstrate a level of familiarity with the local flying area by passing an examination given by the certificate holder within the 12 calendar months prior to using the local flying area.