Former Indycar driver and motorsport safety innovator Bill Simpson has died following a stroke.
Between 1968 and 1977, Simpson made a total of 52 Indycar starts, with a best finish of sixth place at Milwaukee in 1970.
His earlier drag racing exploits first triggered his interest in safety after a severe crash in 1958 left him with two broken arms.
That led to his idea of a safety parachute to slow down the Top Fuel cars of the era - a system that was adopted by drag-racing legend 'Big Daddy' Don Garlits.
After that development, Simpson worked on increasingly effective driver protection devices - helmets, firesuits, gloves and shoes - making big breakthrough with Nomex when working for NASA.
In the 1967 Indianapolis 500, 30 of the 33 starters used Nomex firesuits.
Simpson became famous for setting himself on fire to prove his products' effectiveness, but he was also a strong advocate of improving the safety devices on cars.
For many years badgered NASCAR about developing what became known as 'crumple zones' to help absorb energy during impacts.
Simpson safety belts became one the motorsport industry's standards, but the failure of a belt during Dale Earnhardt's fatal crash at Daytona in 2001 caused NASCAR to state that this was a contributory factor in his death.
Simpson said the failure was not caused by a manufacturing defect but by incorrect installation, as Earnhardt preferred the greater comfort offered by a customised installation.
After trying to sue NASCAR for $8.5m, Simpson settled out of court, but left Simpson Performance Products.
Subsequent medical investigations into the accident concluded that a basilar skull fracture was the cause of Earnhardt's death, due to inadequate head and neck restraints.
Simpson went on to form the safety equipment company Impact! and continued his quest to improve driver safety.
He entered the Motorsports Hall of Fame in America in 2003, and the Indianapolis Motor Speedway Hall of Fame in 2014.
He also developed lighter and stronger American Football helmets, as players suffering concussion became ever an ever more prominent issue.
Another noteworthy highlight of Simpson's career was providing four-time Indianapolis 500 winner Rick Mears with a car for his first Indycar start in the 1976 Ontario 500.
Simpson chronicled his life in the books - 'Racing Safely, Living Dangerously' and its sequel, 'Through the Fire'.
A celebration of Simpson's life is being planned at the IMS Museum for May 2020.