McLaren has agreed to change the specification of its rear wing after complaints from rivals that flexing is giving the car a 'mini DRS' effect offering a key performance advantage.
The rear wing was introduced last week at Azerbaijan, which was won by Oscar Piastri ahead of Charles Leclerc and George Russell with Lando Norris putting in a storming recovery drive to finish in fourth having started from 17th.
Television footage of the race showed the the edges of the wing flap flexing upwards at high speed. The FIA looked into the wing and initially deemed the deformation to be within the acceptable tolerance laid down by the rules.
However complaints from other teams - in particular Red Bull - prompted the governing body to look again and reopen discussions about the situation with McLaren.
Just prior to the start of second practice at Singapore, McLaren announced that it had made changes to the wing as a precautionary measure, while not accepting that the part had broken the rules in any way.
"While our Baku rear wing complies with the regulations and passes all FIA deflection tests, McLaren have proactively offered to make some minor adjustments to the wing following our conversations with the FIA," the team said.
The statement added pointedly: "We would also expect the FIA to have similar conversations with other teams in relation to the compliance of their rear wings."
McLaren will be allowed to continue to use the wing this weekend, as long as it not observed to behave in the same manner as was seen on rearward facing cameras mounted on Piastri's race-winning car last week.
Red Bull team principal Christian Horner had been said by sources in the paddock to have been lobbying hard behind the scenes for the FIA to take action, but has not made his thoughts on the matter public so far.
However Ferrari team boss Frederic Vasseur had suggested that the wing was “more than borderline” and that the matter was “frustrating” given how close this year's championship was turning out.
"The front wing we all agree that it could be a grey area. The rear wing is different because in the [relevant] article [in the sporting regulations] there is a maximum deflection and this is black or white, no grey.”
there will be no retroactive punishment for McLaren over the use of the rear wing in Baku. Only the wing McLaren uses at high-speed, low-drag circuits is affected by the FIA intervention.
The next race at which the wing would be likely to appear after Singapore is the Las Vegas Grand Prix in November.
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