if the decision makers were truly smart, they would've asked to use a provable programming language like Coq, or at least haskell or something like that (i hear Ada is very popular in millitary software because of it's contract based programming).
Also, ADA is _a bit_ popular, but not too much. Most of the code is still done in C because of the conformism. Object oriented programming is still considered like a dangerously modern move. The rules here are pretty hard and it's easier to fuck up the regulation than the code... (cough A330 Neo cough)