Explained: The FIA clampdown on F1’s ‘flexible wings’ saga

McLaren driver Oscar Piastri leads at the start of the Brazilian GP sprint race
Last week, the FIA informed the teams that a revised technical directive, TD018, will come into effect from the 2025 Spanish Grand Prix.
The new technical directive will see teams put through more stringent flexibility tests from the ninth round of the F1 2025 championship, following the FIA embarking on a fact-finding mission during last season.
FIA moves to introduce new flexibility tests
The topic of aeroelasticity became a major one during 2024, with ‘flexi-wings’ allowing teams using them to optimise their balance between maximising downforce through corners with reducing drag and keeping stability down straights.
McLaren found itself the topic of scrutiny following the Azerbaijan Grand Prix as its rear wing displayed a ‘mini-DRS’ effect down the straights of the Baku City Circuit, leading to the Woking-based squad making “proactive” changes to its range of rear wings in deference to the FIA.
With McLaren and Mercedes’ front wing, in particular, attracting attention as they maximised the potential of permissible levels of flexibility, their chief rival teams took notice – and began vociferously questioning their use with the FIA, leading to the governing body carrying out research to evaluate whether its static load measuring tests were up to scratch.
Ahead of the F1 2025 season, with the field of cars for this year’s championship almost fully completed and ready to hit the track, the governing body appeared to turn back on its initial plan to keep the status quo for this season by way of introducing revisions to technical directive TD018.
On paper, this could have been seen as a highly disruptive move – this change, if not communicated in advance, would have a significant impact on a team’s design approach to the season, even with the eight-race leeway introduced. After all, the entire balance of a car can be hugely different based on these very different front-wing profiles.
In December 2024, FIA single-seater chief Nikolas Tombazis told Autosport that the intention was to keep the same static load tests in place for this season, saying,?“Obviously, there was a lot of hoo-hah about it during the summer and early autumn.
“We had made it quite clear to teams since 2022 at least, that we were not planning to introduce any further tests on the front wing and we stuck to that.”
But, just weeks after this, the FIA did issue its guidelines to the teams for the revised TD018 which will reduce the permitted level of flexibility across the front wing – which, despite its apparent suddenness, multiple sources have indicated came as no surprise having been under discussion for several months.
“Following further analysis carried out by the FIA Single Seater Department after the conclusion of the 2024 season, we are committed to ensure that bodywork flexibility is no longer a point of contention for the 2025 season,” an FIA spokesperson told PlanetF1.com.
“As part of this effort, we will be increasing the scope of rear wing tests from the start of the 2025 season, and additional front wing tests being introduced from the Spanish GP. This phased approach allows teams to adapt without the need to discard existing components unnecessarily.
“These adjustments are aimed at further refining our ability to monitor and enforce bodywork flexibility regulations, ensuring a level playing field for all competitors to promote fair and exciting?racing.”
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Why is the FIA introducing more stringent static load tests?
The issue – which could be viewed as an attempt to peg back the pace of McLaren, whose MCL38 won the Constructors’ Championship – stems back to last summer, and the clampdown has led to questions about which – if any – of the leading teams are likely to be put out by the changes, which will see the permitted level of flex reduced from 15mm of movement to 10mm.
With concerns expressed about the level of flexibility of some teams’ front wings during last season, flexibility which was visible via onboard TV footage, the FIA rolled out TD034G at last year’s Belgian Grand Prix.
This technical directive allowed the governing body to begin evaluating whether the existing static load tests – of which every team passed every test in parc ferme – were sufficient to keep ahead of the latest innovations being rolled out on the cars.
Explaining the situation at the time in a statement to PlanetF1.com, an FIA spokesperson said: “The FIA has decided, starting from Belgium onward for an indefinite period of time, to measure the overall front wing deformation on track. The FOM forward-facing cameras are unfortunately not capable of capturing the complete front wing as a large outboard part is not covered by the angle.
“The intent will therefore be to measure across several events all front wings with a camera provided by the FIA which will be installed on the nose (in place of current camera housings) offering a sideways view. The collected data will be used to enhance the overall understanding of bodywork flexibility when defining future regulations.
“It is also reiterated that all front wings checked so far this season have passed the existing deflection tests and are deemed legal. This new technical directive is the result of a long-standing desire to better capture front wing behavior under aerodynamic load.”
With the exercise of data-gathering carrying on over several Grand Prix weekends, the complexion of the story became clearer as Red Bull and Ferrari highlighted their concerns over the level of front-wing flex seen on the McLaren MCL38 and the Mercedes W15.
The FIA opted against taking any steps to tighten up its testing methods during 2024, with the governing body stating that, “the front wing has been a challenging area throughout the years, because the aerodynamic loading patterns between different competitors varies and it is therefore difficult to find a load vector which will cover all types of front wing construction.
“Other areas of the car – including rear wing and floor edges – have much more consistent aerodynamic loading patterns across the grid, making for a more universal load-deflection test.
“The FIA has the right to introduce new tests if irregularities are suspected. There are no plans for any short-term measures, but we are evaluating the situation with the medium and long-term in mind.”
When was the decision made?
Given the FIA’s initially lenient stance on the practice, both Red Bull and Ferrari had indicated intentions of pursuing the development of more flexible front wings for their cars for F1 2025, citing the performance gain available from the practice, if the FIA didn’t seek to clamp down on it.
Ferrari rolled out with a more flexible front wing at the Singapore Grand Prix –?the Scuderia going on to win races in the United States and Mexico – with team boss Fred Vasseur later explaining that the Italian manufacturer had initially been reluctant to divert finances and resources into a more flexible front wing having expected a clampdown.
“There was frustration because at one stage we were waiting for the decision of the FIA when they installed the cameras,” he said.
“We were convinced that it would go for the ‘no go’. And it went for the ‘go!’ So probably we lost one or two months.”
However, PlanetF1.com now understands that the FIA informally made its intentions regarding the potential introduction of the new technical directive guidelines known in late November 2024, with the governing body working on the “ongoing” issue throughout the winter.
While the exact details of the proposals to alter the existing load tests has changed over the past two and a half months, the intention was made clear to the teams that a change was very likely – meaning that every team has been armed with the knowledge that wings designed to maximise the regulations would have a very uncertain shelf life.
Given the near-certainty of the imposition of more stringent load tests, it’s therefore unlikely that many of the leading teams will have devoted much by way of time or resources into developing more flexible front wings given this limited shelf life – particularly with all teams needing to balance the development of their 2025 cars against the demands the new regulation cycle coming in 2026 will have.
Certainly, multiple sources across the grid have indicated there’s no cause for concern over a major change in the pecking order as a result of the changes, although it’s understood the reduced flexibility available may make finding the ‘sweet spot’ of setup more difficult.
What impact will the changes have on the leading teams?
If the leading teams continue in the same direction they ended 2024 in, it’s therefore Red Bull who may start this season on the back foot. The Milton Keynes-based squad didn’t roll out a more flexible solution during 2024, and it’s understood that the advance notice of the possible technical directive meant no further time or resources were poured into developing one over the winter.
It remains to be seen what front wings the teams will roll out with for the start of the F1 2025 season – designs that conform to the current static load tests or to the stricter tests – which is obviously information teams will aim to keep as close to their chests as possible.
But it’s certainly not unthinkable that teams with more flexible designs will seek to make the most of them and work to comply with the test in place at any individual race – meaning racing for eight weekends with the optimal design before switching to a revised version from Spain onwards.
Given the majority of the season will run under stricter rules, the benefits offered by running more flexible solutions will be short-lived but could be substantial over the first eight race weekends of the season.
How this could backfire is if a handle on finding the setup sweet spot for after the more rigid tests are introduced isn’t properly developed over that timespan.
This would suggest that any of the leading teams with more flexible solutions might, be more inclined to run with wings according to the stricter rules right from the offset – while the performance disadvantage might be noticeable over the first third of the season, it will allow the teams to fully understand their car’s handling well in advance of the technical directive clampdown.
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