re: B-17 collides/crashes with another plane at Dallas air show.

They don't fly those old planes 'hard', for the most part.
No combat maneuvers and crazy antics. Easy does it. No hard G loadings. They're museum pieces, and treated as such. The P-63 pilot might have been able to turn tighter, but stayed within the performance limits they fly under, while unaware how close he was to the B-17. Which goes back to the point that there was a planning or procedural error that took place, ie too short a gap between the fighters and bombers doing the parade lap, and other things that have been mentioned.

As long as people like Kermit Weeks are around, they'll be flying plenty of those old birds, unless the cost become just too prohibitively expensive as the years go. I hope he'll make some kind of content about this.