Every former DoD engineer I've spoken to has worked pretty extensively in Ada. From the Phalanx, to the F-15/F-16. C++ didn't start becoming popular in those domains until the mid-00s. The first fighter jet to use it extensively was the the F-35[1], which many of the engineers attribute to it's early issues[2]; not because C++ was bad, but because so much well-tested and hardened code had to be replaced.
So, wherever these waivers were, they certainly weren't in those spaces.
> because so much well-tested and hardened code had to be replaced.
Not just software, entire systems. They built their own datalinks instead of aiming for compatibility with existing datalinks or pushing those existing datalinks to a newer version that could meet their needs.
In principle, that should have been their first (flight test ready) version. Just get the planes talking to an existing datalink network even if they had some next gen datalink target. But this is also a classic DOD project management problem. They aim for the full system instead of staging out a series of iterative versions.
And LM, in their infinite wisdom, hired more developers when they were late and ran their development in shifts. Because everyone knows the best way to get a late project back on track is to hire more people...
As an intern I worked in Ada at a defense contractor, it seemed matter of fact for everyone around me who had worked in the field for decades. I'm not sure "vanishingly" is the correct adjective here.
Vanishingly little was written in Ada as waivers were too easy to get.