Nothing fly's in the UK air show system with out being signed off by the governing body. In our case, EASA and the CAA. Our team is sponsored by Sydney Charles aviation insurance, so we are covered up to the hilt, as for the fire works, they are hand made for us and burn for 60 seconds. our min fire height is 1000 feet, so if the engine stopped as we fired the pyros, we would still be above 700 feet as they burnt out. In still air at 28 to 1 we can glide 5 miles from 1000 feet. Nothing is with out risk and we keep it to a minimum.
If you have any other questions, Email me.