Hamilton and Leclerc referred to F1 stewards for potential plank rules breach

In arguably Mercedes’ most competitive showing of the season, Hamilton enjoyed stellar race pace during the final stint to close to within 2.25 seconds of eventual winner Max Verstappen.

Leclerc, meanwhile, suffered as a result of Ferrari’s decision to attempt a one-stop strategy to leave him vulnerable in the closing stages as he dropped to sixth place.

But both drivers have now been referred to the FIA stewards after their cars were found to fail compliance checks governing the skid blocks.

The two drivers are potentially in breach of Article 3.5.9 e) of the 2023 Formula 1 technical regulations.

This section reads: “The thickness of the plank assembly measured normal to the lower surface must be 10mm [plus or minus] 0.2mm and must be uniform when new.

“A minimum thickness of 9mm will be accepted due to wear, and conformity to this provision will be checked at the peripheries of the designated holes.”

Photo by: Andy Hone / Motorsport Images

Charles Leclerc, Ferrari SF-23, Max Verstappen, Red Bull Racing RB19, Carlos Sainz, Ferrari SF-23

Due to the Austin, Texas round running to a sprint race format, parc ferme regulations set in after the single one-hour practice session early on Friday afternoon. That leaves teams limited with the set-up revisions they can make.

For example, ahead of the Azerbaijan GP earlier this season, which also ran to sprint rules, Alpine opted for a pit lane start for Esteban Ocon so that it could brake parc ferme and tweak the suspension settings to preserve the plank.

This weekend, drivers have noted that the Circuit of The Americas is markedly bumpier than previous visits, with the cars upset through the Turn 1 apex.

Verstappen referred to the track as being like a ‘rally stage’ and no longer up to F1 standards.

The course has been resurfaced at Turn 12 and from Turn 14 to 16 in an attempt to alleviate the problem, which left Aston Martin performance director Tom McCullough to liken the different Tarmacs to being a “patchwork quilt”.