Hardly the same thing though. Astrée is a static analyzer used to help prove avionics code written in C, it's not used in any onboard avionics systems. So its lack of real-time processing is not important.

If you're writing real-time avionics software, your choices are really only Ada, C and C++. Most companies I know of, including Airbus, are using C. Typically, avionics software has to be qualified to DO-178B/ED-12B standards which specifies certain development, testing and proofing requirements. Software verification tools like Astrée are also governed by DO-178B/ED-12B, though they are subject to a lighter verification process.