AUSTIN, Texas — A technical violation cost Lewis Hamilton second place in the US Grand Prix and disqualified Charles Leclerc from the race.
After the checkered flag, Hamilton’s Mercedes and Leclerc’s Ferrari were scrutinized by the FIA and found to have breached Article 3.5.9. e), which is related to wear and tear on the undercarriage.
The disqualification forced Hamilton into a hard-fought second position, where he closed on race winner Max Verstappen in the final stages.
Leclerc, who started the race from pole position, finished sixth.
The article in question states: “The thickness of the plank assembly measured normal to the bottom surface must be 10 mm [plus or minus] 0.2 mm and shall be uniform when new.
“A minimum thickness of 9 mm shall be adopted due to wear, and compliance with this provision shall be checked at the perimeter of designated holes.”
In the ruling, the stewards said “the high wear on the ski pads was likely a result of the unique combination of dark tracks and sprint race schedules that reduced car set-up and check times before the race.”
The decision to throw both cars out of the results was confirmed shortly before 7:30 p.m., nearly four hours after the end of the race.
The plank — a strip of wood resin affixed to the bottom of the car — is used by the FIA to measure how lesser teams are driving their cars and prevent them from exploring potentially dangerous setup choices.
Running a lower car can give a performance advantage, but as a car is set up to run lower, the planks wear more as they scrape along the track surface.
If the thickness of the plank falls below 9 mm at any of its four measurement points, the car will be considered invalid and disqualified from the results.
After the US Grand Prix four cars were selected to be tested for plank wear: Verstappen, Lando Norris (who finished second after Hamilton was disqualified), Hamilton and Leclerc.