Constituting the Sixth Supplemental Ordinance to the Amended and Restated General Airport Revenue Bond Ordinance; authorizing the Mayor, the City Controller and the City Solicitor, or a majority of them, to issue Airport Revenue Bonds, of the City of Philadelphia, in a maximum aggregate principal amount not to exceed two hundred thirty million dollars ($230,000,000) exclusive of certain items, and in the event the Airport Revenue Bonds are issued with such items, authorizing an increase in the aggregate principal amount of such Airport Revenue Bonds, so issued, by the amount of such items; des — Open Common Ground