The 1990 Formula 1 season would see both Ayrton Senna and McLaren emerge victorious once again in the World Drivers and Constructors championship. With Alain Prost departing McLaren for Ferrari after winning of the Driver’s Championship in 1989, Senna was paired with Gerhard Berger, both now behind the wheel of the McLaren MP4/5B. Despite Senna winning six grands prix across the season and finishing on the podium in most of the other races, the season was not without its challenges.

All the teams on the grid, McLaren included, took notice of Tyrrell’s innovative “high-nose” design on their car at the opening round of the 1990 Formula 1 World Championship; the United States Grand Prix at Phoenix. That weekend saw Jean Alesi, who was just starting his first full season in Formula 1, not only out-qualify Ayrton Senna but also pull away from Senna, Berger, and the rest of the pack to take the lead at the start of the race. McLaren’s engineers sought to replicate Tyrrell’s nose on the MP4/5B, which was fitted for the first and only time at a test in Monza in August of 1990. McLaren struggled to make the aerodynamics work during the test and decided to continue with their initial nose design instead.

According to photographic research undertaken by helmet designer and historian Mike Fairholme, it was the helmet offered here that Senna wore during that particular test at Monza. Unusually, as the helmet was only used in testing, it does not bear the usual sponsor logos Nacional and Hugo Boss, with the Marlboro logo being the Chevron design for events where Tobacco advertising was not permitted. The Marlboro logo was present at Monza, but has subsequently been removed. There is no Snell label present inside. Nor is there evidence of a radio being fitted, but this was often the case for helmets used during testing.

On file is a letter from Alan Sidney Mosca, the son of Sidney “Sid” Mosca, the man who designed and initially painted Ayrton Senna’s iconic design that chronicles the helmet’s provenance following use by Senna. This helmet was gifted to Alan Sidney Mosca by Senna himself, alongside another helmet donated to his father. Remaining with Alan from 1991 until 2018, before the helmet was acquired by the current owners in 2021. The letter states this helmet was used by Senna in 1991. However Rheos had produced an all-new design for Berger and Senna’s helmets in 1991, to replace the 1990 type which was based on a version used in motorcycle racing, This led to the earlier helmets being retired from use on the introduction of the 1991 model.

The short timeframe of collaboration between Senna and Rheos leaves only a small number of Senna-worn Rheos helmets in existence. As they were only supplied for Senna and Berger, the number of Rheos Formula 1 helmets are exceptionally limited, with helmets used exclusively in testing even rarer. This would be a fascinating addition to any collection, as it marks an interesting side note within the history of McLaren.