Section 243.71 - Refunding bonds(1) The authority may provide for the issuance of revenue bonds of the authority for the purpose of refunding any revenue bonds of the authority then outstanding, including the payment of any redemption premium thereon and any interest accrued or to accrue to the earliest or subsequent date of redemption, purchase, or maturity of the revenue bonds, and, if considered advisable by the authority, for the additional purpose of paying all or any part of the cost of constructing and acquiring additions, improvements, extensions, or enlargements of a project or any portion thereof.(2) The proceeds of any revenue bonds issued for the purpose of refunding outstanding revenue bonds may be applied to the purchase or retirement at maturity or redemption of the outstanding revenue bonds on their earliest or any subsequent redemption date or upon the purchase or at the maturity thereof and may, pending the application, be placed in escrow to be applied to the purchase or retirement at maturity or redemption on the date determined by the authority.(3) Any escrowed proceeds, pending use, may be invested and reinvested in direct obligations of the United States, or in certificates of deposit or time deposits secured by direct obligations of the United States, or in other investments as the resolution authorizing the issuance and sale of the bonds or the trust agreement provides, maturing at the time or times as is appropriate to assure the prompt payment, as to principal, interest, and redemption premium, if any, of the outstanding revenue bonds to be refunded. The interest, income, and profits, if any, earned or realized on any such investment may also be applied to the payment of the outstanding revenue bonds to be so refunded. After the terms of the escrow have been fully satisfied and carried out, any balance of the proceeds and interest, income, and profits, if any, earned or realized on the investments thereof may be returned to the authority or to the participating institution for use by it in any lawful manner.(4) The portion of the proceeds of any revenue bonds issued for the additional purpose of paying all or any part of the cost of constructing and acquiring additions, improvements, extensions, or enlargements of a project may be invested and reinvested in direct obligations of the United States, or in certificates of deposit or time deposits secured by direct obligations of the United States, or other investments as the resolution authorizing the issuance and sale of the bonds or the trust agreement provides, maturing not later than the time or times when the proceeds will be needed for the purpose of paying all or any part of the cost. The interest, income, and profits, if any, earned or realized on the investment may be applied to the payment of all or any part of the cost or may be used by the authority or the participating institution in any lawful manner.(5) All refunding revenue bonds are subject to ss. 243.50 - 243.77 in the same manner and to the same extent as other revenue bonds issued under ss. 243.50 - 243.77.