Statistics
To my knowledge (and I stand by to be corrected) the number of members of the public killed at a UK airshow since 1952 = 0.
We had crowd overflight arrivals banned whilst I was in the Reds but I believe they are now allowing it back in (in a controlled manner).
The crowd line distances are sufficient for the debri-hemisphere of a crash to not affect the paying public.
Airshows are more than safe enough if you pay your money and stand behind the barrier.
KMB01