In City of Philadelphia v. Fraternal Order of Police, Lodge No. 5, 564 Pa. 290, 768 A.2d 291 (2001), our Supreme Court reaffirmed an appellate court's limited review of an Act 111 arbitration award as follows: Act 111 altered the landscape of employer-employee relations. While the legislature maintained the prohibition on striking by police and fire personnel, 43 P.S. 217.5, it granted to the workers the right to collectively bargain as well as the right to an arbitration of their disputes. These arbitration provisions were one of the key aspects of the legislature's plan to ensure stability within the police and firefighting forces. The legislature designed Act 111 arbitration to be swift and final; it allowed judicial intervention in the Act 111 context in only the rarest circumstances. Pennsylvania State Police v. Pennsylvania State Troopers' Ass'n (Betancourt), 540 Pa. 66, 656 A.2d 83 (1995). . . . Our review therefore is a very constricted one and is in the nature of narrow certiorari. Narrow certiorari allows us to inquire into only four aspects of an Act 111 arbitrator's award: (1) the jurisdiction of the arbitrator; (2) the regularity of the proceedings; (3) an excess of the arbitrator's powers; or (4) the deprivation of constitutional rights. Betancourt, 656 A.2d at 85. Id. at 294-95, 768 A.2d at 294.