The B17 can stay flying in the same way the B52 and the A10 is still in active service Jim. Regular inspection and maintenance schedules that are strictly adhered to and they can fly conceivably forever.
I find it very hard to swallow that after 85+ years they suddenly find a defect in the design of the wing spar grounding all flying examples? A week before the Memorial Day air shows kick off? Not trying to do wrong by the site here but it reeks of dirty politics.