At least, that's the only reason I can see for the Red Arrows doing a low level pass, complete with smoke trails, over our garden a moment ago.
EDIT: a check of the Duxford site doesn't list anything. On the other hand, the Red Arrows were just down in London an hour or so ago celebrating Brenda's 80th. Why they'd still be at low level 45 miles away, goodness knows. Maybe they're practising.