The Karting World Championship takes place this weekend in Sweden, at the Kristianstad raceway. In the same competition, 39 years ago, Ayrton Senna wore his iconic yellow helmet for the first time. The championship took place in 1979, from September 18 to 23, at the Estoril Go-Kart Track, in Portugal.

A few days before the trip, Senna and the Brazilian delegation reached out to Sid Mosca, who had created designs for great Formula One drivers, in order to nail down a layout for the Brazilian drivers’ helmets. At the time, each country had its own color scheme, which meant all Brazilian drivers had to wear the same layout, as stipulated by the competitions’ rulebook.

In Portugal, Senna and his DAP teammate, Peter Koene, ended up tied for first place. In a controversial decision, Koene was declared champion, with Senna as the runner-up. According to the Brazilian team, if two drivers ended up with the same amount of points, the champion should be whoever finished the last of the three finals in a better position – and Ayrton had easily won that race.

The Championship directors, on the other hand, understood the rules differently. They gave Koene the title based on his performance in the semifinals, which he finished in fourth place, while Senna was eighth. During that race, the Brazilian was in second place until the last few laps, when the leader had issues with his vehicle right in front of Ayrton, who wasn’t able to avoid the collision and ended up spinning out.

Upon his return to Brazil, the driver talked to Sid in order to make that helmet his personal trademark – and its design would soon become legendary, thanks to Ayrton’s performance in Karting, Formula Ford, F3 and F1. So maybe Ayrton didn’t walk away with that year’s world champion trophy, but that competition gave him his most iconic feature on the track.

Learn more about Ayrton Senna’s helmet on the two installments of Senna TV featuring Alan Mosca, son of Sid Mosca, who followed in his father’s footsteps.