The KVUE article above has one of the better videos from the spectator area that shows a wider view of what all the planes were doing, not just the two involved in the collision.
In the video, you can see smaller planes running a faster, tighter inside path and larger planes flying a slow, wide outside path. Pretty common for air shows.
By design, those two planes should not have been near each other. Either the B-17 was encroaching on the inside track or the P-63 ran wide of his inside path.
Armchairing it, I'd say the P-63 left his designated course. The Air Boss is the guy that'd know for sure, though.
In the video, you can see smaller planes running a faster, tighter inside path and larger planes flying a slow, wide outside path. Pretty common for air shows.
By design, those two planes should not have been near each other. Either the B-17 was encroaching on the inside track or the P-63 ran wide of his inside path.
Armchairing it, I'd say the P-63 left his designated course. The Air Boss is the guy that'd know for sure, though.