"The Tucker Act, the principal statute governing the jurisdiction of this court, waives sovereign immunity for claims against the United States, not sounding in tort, that are founded upon the Constitution, a federal statute or regulation, or an express or implied contract with the United States. "
However, the Tucker Act is merely a jurisdictional statute and “does not create any substantive right enforceable against the United States for money damages. Instead, the substantive right must appear in another source of law, such as a “money mandating constitutional provision, statute or regulation that has been violated, or an express or implied contract with the United States.”
Clearly SPSPA is a express (or implied) contract with the United States that waives sovereign immunity for claims against the United States for both tort and non-tort claims.