Modification of Class E Airspace; Polson, MT

This final rule will modify the Class E airspace at Polson, MT. New Area Navigation (RNAV) Global Positioning System (GPS) Standard Instrument Approach Procedures (SIAPs) have been developed at Polson Airport making it necessary to increase the area of controlled airspace. This additional Class E airspace extending upward from 700 feet or more above the surface of the earth is necessary for the safety of Instrument Flight Rules (IFR) aircraft executing these new SIAPs and when transitioning to/from the en route environment.