This paper describes the specification-based testing and analysis tools, and associated processes, that were used to develop and certify safety-critical avionics systems in an industrial organization. These tools comprise an integrated development environment supporting specification acquisition and analysis, requirement-based automatic test vector generation, test coverage analysis, test driver generation, and test results analysis. The paper describes the specification model, method, development environment, and tool qualification approach. The capabilities of the automatic test generator are compared with foundational concepts and related testing strategies and mechanisms.