Lewis Hamilton and Charles Leclerc's disqualification explained by F1 aero expert

lewis hamilton and charles leclerc — Photo: © LAT Images

F1 Analysis

Hamilton and Leclerc's disqualification explained by F1 aero expert

GPFans' aerodynamics expert Shubham Sangodkar explains why Hamilton was disqualified

Shubham Sangodkar

Monday 23 October 2023 18:43

The United States Grand Prix proved to be a race all about strategy. Eventually, Mercedes with Lewis Hamilton were tantalisingly close to a win with their late two-stop while Ferrari with Leclerc lost out by attempting a one-stop.

The Silver Arrows ran a new floor at this event, with Mercedes bringing their last major upgrade package of the year to Austin, Texas.

Despite their efforts, Hamilton and Leclerc's results were completely scrubbed from the board, with both cars being deemed illegal due to excessive floor plank wear.

In this article, GPFans will break down the rules and regulations governing this incident.

Lewis Hamilton and Charles Leclerc were disqualified from the United States Grand Prix

Why is the plank present?

The wooden plank is a way of the FIA regulating minimum ride heights. It’s present for performance and driver safety.

If a team sets up an F1 car really low with the new ground effect regulations, you can go faster but it also makes your car bounce if the track has bumps.

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Excessive bumps can result in a sudden loss of aerodynamic forces and can also cause aerodynamic instability such as porpoising.

Porpoising can cause damage to the drivers as seen in some cases during the start of the 2022 season.

In order, to govern this, article 3.5.9.e of the technical regulations says that the wooden plank has to be a minimum of 9mm thick when checked post race and it’s an automatic disqualification if cars don’t meet this criteria.

So what happened?

Post-race, Mercedes and Ferrari representatives were called in by the stewards, who argued that the high wear on the skid pads, was likely a result of the unique combination of the bumpy track and the Sprint Race schedule, which minimised the time to set up and check the car before the race.

However, the Stewards noted, "the onus is on the competitor to ensure that the car is in compliance with the regulations at all times during an event. In this particular case, the rear skid in the area defined in the Technical Delegate’s report was outside of the thresholds outlined in Article 3.5.9 e) of the FIA Formula One Technical Regulations, which includes a tolerance for wear."

Lewis Hamilton's Mercedes W14 throwing up sparks at the Circuit of the Americas

It seems that a combination of factors contributed to Hamilton and Leclerc's disqualification.

It's possible that the F1 stars were simply too aggressive when cornering some kerbs.

However, a more likely out is that Mercedes and Ferrari ran their ride heights too low and were caught out by the vigorous bumps at the Circuit of the Americas.

After all, the Austin circuit is known for a geological phenomenon called “subsidence” which causes the soil underneath the track to sink in certain places due to geological activity. Something the teams will have to keep in mind next time they head to Texas.

Shubham Sangodkar is a former F1 Aerodynamicist with a Master's in Racing Car Design specialising in F1 Aerodynamics and F1 Data Analysis. He also posts aerodynamics content on his YouTube channel, which can be found here.