I believe the reason the Vulcan appeared on the Portrush site was that a fee had been aggreed by both partys for the Vulcan to appear...
.and also appear at the Southport airshow at the same time...but due to the rise in fuel and mantaince costs the Vulcan team decided to up their fee.....
so the Southport show decided to pull out because it was too high for them....
and then the Vulcan team raised their fee to appear at Portrush even further and then it was decided to drop it from the show there too....
so it seems that the Vulcan team has priced themselfs out of most small and medium sized shows this year and some of the shows that have booked them are having second thoughts about doing it again....