Modification of Class E Airspace; Yankton, SD

This action modifies Class E airspace at Yankton, SD. This action amends the effective hours of the Class E surface area from one (1) hour per day to twenty-four (24) hours per day to accommodate regular air carrier operations that occur outside the current times of operation of the surface area. The purpose of this action is to afford an increased level of safety during instrument flight operations for the commercial air carrier operations at the Chan Gurney Municipal Airport.