16 Pa. Stat. § 5516-A
The effectuation of the authorized purpose of Authorities created under this article shall and will be in all respects for the benefit of the people of the Commonwealth, for the increase of their commerce and prosperity and for the improvement of their health and living conditions, and since such Authorities will be performing essential governmental functions in effectuating such purposes, such Authorities shall not be required to pay any taxes or assessments upon any property acquired or used or permitted to be used by them for such purposes, and the bonds issued by any Authority, their transfer and the income therefrom (including any profits made on the sale thereof), shall at all times be free from taxation within the Commonwealth.
16 P.S. § 5516-A