Considering the languages that are normally used to write aircraft control software, this is perhaps a questionable choice of example.

And there are probably very good reasons why a language like Haskell is not likely to be chosen for this kind of application. Consider predictability: Haskell may make it easy to prove algorithmic correctness, but its laziness makes runtime characteristics more difficult to reason about because they're hidden behind so much abstraction. This could make it very difficult to deal with stuff like subtle bugs related to timing issues that might crop up in an electromechanical system.