A British driver who was the first person to break the sound barrier in a car on land has set a new speed record, this time in a hydrogen-powered vehicle. Andy Green, a 64-year-old retired Royal Air Force pilot, reached a speed of 406mph (654km/h) at the Bonneville Salt Flats in Utah, the fastest a hydrogen-powered car has ever travelled. Green's record was measured as an average of two runs in a car powered by two hydrogen internal combustion engines, with a combined 1,600 brake horsepower (bhp). In 1997, Green drove the jet-powered ThrustSSC across Nevada's Black Rock Desert at 763mph (1,228km/h), making him the first, and still the only person, to break the sound barrier on land.