They might have USB drives. I believe that is how Manning downloaded all that info. That isn’t the same as internet access though. They may use flash drives to load flight data which is then stored elsewhere. I would think they would have a hard line for that though. I never had any interaction with any flight equipment.
I have contracted with DISA.
It is full of M$ zealots who believe
that windows is safe.They most likely use Sipernet
which is what was used by Manning.