Common sense and spotters....
A couple of examples came to mind when I read this thread.
RAF Cottesmore around 2000 , when they held the RIAT here.
A large group of spotters on the end of the runway as the B1 wound up and went....smaller gruoup of spotters blown backwards by the blast of four burners.....
The fence at RAF Coningsby is made up of wood panels. The ones in the middle are newer than the ones on the edges. Nobody could work out why until a 'phoon blew them away with a max rate take off. Spotters now stand at the side instead of the middle, proving that Darwin was right.....