53 Pa. Stat. § 41301
Upon the adoption by the qualified voters of any city of any of the optional plans of government set forth in this act, the city shall thereafter be governed by the plan adopted and by the provisions of this act common to optional plans and by all applicable provisions of general law, subject to the transitional provisions of Article VI of this act, unless and until the city should adopt another form of government as provided by law. The plan adopted and the provisions of this act common to optional plans shall become the organic law of the city at the time fixed by this act. So far as they are consistent with the grant of powers and the limitations, restrictions and regulations hereinafter prescribed, they shall supersede any existing charter, and all acts and parts of acts, local, special or general, affecting the organization, government and powers of such city to the extent that they are inconsistent or in conflict therein. All existing acts or parts of acts and ordinances affecting the organization, government and powers of the city not inconsistent or in conflict with the organic law so adopted shall remain in full force until modified or repealed as provided by law.
53 P.S. § 41301