Originally Posted by
Tourist
All aircraft are upgraded over their lifetimes. This is just normal Ops over the lifetime of a design.
From Aviation Week:
...converted from JAS 39Cs but with new engine, avionics and primary structure
The JAS-39C to E conversion sounds a little more comprehensive than a simple 'upgrade' though, '(new) primary structure' sounds like quite a significant part of the airframe will be a new design and build...
-RP