Aeronautics and Space. Part135:Operating requirements: Commuter and on demand operations and rules governing persons on board such aircraft. Section135.611:IFR operations at locations without weather reporting.
(a) If a certificate holder is authorized to conduct helicopter IFR operations, the Administrator may authorize the certificate holder to conduct IFR helicopter air ambulance operations at airports with an instrument approach procedure and at which a weather report is not available from the U.S. National Weather Service (NWS), a source approved by the NWS, or a source approved by the FAA, subject to the following limitations: