No. McCain wasn’t born on the US military base. He was born in the Panama City hospital because the base didn’t have a facility for birthin’ no babies.
I don’t think it was Panama City. It was Cristobal on the Carribean side of the isthmus.
McCain's birth certificate was signed by Captain W. L. Irvine. He was director of the medical facility at the submarine base hospital in Coco Solo, Panama Canal Zone.