 Complete the following phrase:  The FIA introduced a mandatory titanium-carbon fibre halo cockpit protection structure for the 2018 Formula One and Formula 2 championships. Surteess fatal impact was one of many simulated with the halo device, and the FIA concluded that Surteess outcome likely would have been improved by the presence of a halo. The utility of the halo, controversial when introduced, was borne out in the 