AUSTIN, TX – When representatives from Mercedes and Ferrari were summoned to face FIA commissioners after Sunday’s United States Grand Prix, they knew their fate was sealed.
The cars of Lewis Hamilton and Charles Leclerc had both failed a post-race inspection, during which officials found that the skid plates on both chassis were excessively worn, in breach of technical regulations.
At a time when teams meticulously check their cars during a race weekend to ensure compliance with regulations, it is rare to be excluded from the final standings for a technical infringement: since Romain Grosjean’s exclusion from the Italian Grand Prix in the In 2018, no driver was disqualified in a race on such an issue.
Hamilton and Leclerc published a joint Instagram post on Monday morning showing them sitting together, bored and emotionless, during the FIA press conference on Friday. The headline simply read: “Mood.”
It was a shocking end to their two weekends. But how did it happen that two cars from different teams were disqualified for the same rule violation in Austin on Sunday?
This is how the technical acceptance process works
Both Hamilton and Leclerc’s cars violated Article 3.5.9 e) of the FIA’s technical regulations. This rule describes the required thickness and dimensions of the boards under the cars. This is “10 mm ± 0.2 mm” before a race, while during a race a “minimum thickness of 9 mm is accepted due to wear”. Similar design restrictions apply to all parts of the F1 cars.
The plank on the underside of an F1 car is made from a composite material called Jabroc, a type of reinforced beech wood. Its main purpose is to ensure safety and prevent the cars from bottoming out on the track.
The purpose of the plank wear rule is to ensure that teams do not drive their cars too close to the ground. This can provide a performance advantage by increasing the downforce generated by the floors, which is particularly strong under current “ground effect” regulations.
After each race, the FIA carries out a comprehensive technical inspection process, checking various aspects of all cars. This information is detailed in a post-race report from FIA technical delegate Jo Bauer, which will be sent to all participants and made available to the media.
All 20 cars are weighed and examined for things like tire pressure, fuel samples, torque control and oil consumption. In addition, some cars will be randomly selected for additional technical checks. After the Austin race, the cars of Sergio Pérez, Lando Norris and Yuki Tsunoda were selected for aerodynamic component and bodywork tests to ensure compliance with technical regulations. A total of 19 areas were covered including the front wing, rear wing and side pods.
These were separate from the physical floor and plank wear inspections that are routine at racing – they last took place in Singapore – and were carried out on four cars this weekend: Max Verstappen’s Red Bull, Norris’ McLaren, Hamilton’s Mercedes and Leclerc’s Ferrari. These were again selected randomly. It just so happened that two of the four committed an infraction.
Had the FIA not checked the planks on Hamilton and Leclerc’s cars, both would have escaped detection and disqualification.
Team representatives usually go to the hearings together with the sports commissioners and have all possible arguments to avoid a sanction. On this occasion, neither Mercedes nor Ferrari could do anything. The document confirming the disqualification stated that both teams “acknowledged that the measurement carried out by the FIA technical team was correct”.
Ferrari sporting director Diego Ioverno explained that Leclerc’s car was only “a few tenths” outside the requirements. “The code does not allow anything other than disqualification in this case,” he said. It’s a black and white rule, and they were on the wrong side.
Why was plank wear a problem?
Two key factors contributed to the high level of plank wear on both cars in Austin: the sprint weekend format and the unevenness of the track.
As teams make setup tweaks during a race weekend, they check and inspect their cars’ planks to use sensors to measure the level of wear. This will help them find out how much the car is bottoming out, which has become an increasing problem with updated technical regulations from 2022.
But the sprint weekend format only gave teams a single hour-long practice session to fine-tune their cars before finalizing their setups. From the start of qualifying on Friday, car settings could no longer be changed without requiring a pitlane start, which is a major disadvantage, particularly for teams starting high up on the grid. On a normal weekend, it is possible that both Mercedes and Ferrari would have realized that the planks were showing too much wear and increased their ride height accordingly.
Ioverno explained that Ferrari raised the ride height of its cars in response to the bumpy asphalt at the Circuit of The Americas in FP1, which has been a recurring problem over the years. After the race, Verstappen said COTA was “more suitable for a rally car” and needed to be repaved to make it smoother for drivers.
“In the past, more or less everyone has had suspension and chassis failures,” Ioverno said. “We knew it was going to be difficult and that’s why we lifted the car throughout FP1. From our perspective it should have been fine. It turned out we were too marginal anyway.”
That meant wear levels were just above that as Hamilton and Leclerc’s cars dealt with the bumps, used a lot of fuel and were exposed to stronger winds during the 56-lap race than at the start of the weekend, which also affected handling of the car affected the permitted amount.
F1 teams will always try to push the technical regulations to the limit to beat their rivals. But this time the factors combined to push Hamilton and Leclerc’s cars too far.
“In hindsight, we may have lifted the car even more,” Ioverno said. “But we would have lost performance. We are always here to optimize our own performance.”
(Main photo of Lewis Hamilton and Charles Leclerc: JIM WATSON/AFP via Getty Images)