[constantcrying]

Sure, I have worked on multiple plane systems which were connected wirelessly, even to the internet. (Although that is something which I am extremely glad I have left behind me and would never brag about in my profile name)

Even though, a modern jet is still able to function without internet.

[joe_the_user]

Yes but my point is whether the system can be "never on the Internet" (hence never subject to constantly evolving hacks) and it doesn't seem like the systems you describe are necessarily that.