Constituting the Twentieth 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 and sell one or more series or subseries of tax-exempt or taxable airport revenue bonds or notes of the City of Philadelphia; setting forth the use of proceeds; determining the sufficiency of pledged Amounts Available for Debt Service; covenanting for the payment of interest and principal; authorizing the Bond Committee to take certain action with regard to the terms and condition