Mercedes DDA judged legal by Spielberg commissioners

Of course, we had to wait until 00:45 a.m. on the night of Friday to Saturday before the Austrian Grand Prix, but at least everyone is now settled. The ingenious dual-axis steering (DDA) introduced by Mercedes on his W11, which allows the driver to adjust the toe-in of the front wheels by pulling on the steering wheel while the car is moving, was deemed legal by the Spielberg Stewards. 

After threatening to file a claim in Australia, Red Bull had the merit of following through on his approach for his home meeting by filing a double complaint against the Silver Arrows, who had become black, at the end of Free Practice 2 of the first effective round of the season, contested this weekend in Styria. 

Both parties were summoned before the sports commissioners, physically or via videoconference. Attending the meeting were Paul Monaghan (chief engineer), Adrian Newey (technical director), and Jonathan Weathley (sporting director) for Red Bull; James Allison (technical director), Ron Meadows (sporting director), John Owen (chief designer), and Andrew Shovling (engineering director) on the Mercedes side; as well as Nikolas Tombazis, head of the FIA ​​single-seater series. 

The Milton Keynes team (United Kingdom) considered that the DDA was in breach of Articles 3.8 and 10.2.3 of the technical regulations. Namely that any element of the car which has an influence on its aerodynamic performance must remain immobile in relation to the suspended part of the car. And that the suspension system cannot be adjusted while the car is moving.

The FIA ​​technical department carried out an analysis of the Mercedes system and the stewards scrutinized the elements of the car concerned.

In their verdict, 6 extremely detailed pages long, the officials notably explain Red Bull's grievances, of which here is an extract below: 

« The technical regulations authorize several steering systems. The primary purpose of a steering system should be to steer the car. Any secondary system that is not capable of steering the car by itself is not necessary. 

Based on video footage taken during free practice, the device appears to only be used during launch laps or at reduced speeds as a means of adjusting tire temperature. Its primary function is therefore not to steer the car but to manage the temperature of the rubber.

The DDA is therefore an independent and redundant system which requires action from the pilot and components which deviate in their effects from the main steering system. ».

In its defense, Mercedes set out to demonstrate that the DDA was indeed a steering system and not a suspension element.

« The DDA is not a suspension element because:

•    It plays no suspension role and does not isolate the car from the undulations of the track surface. 
•    The system is mounted entirely on the steering column
•    The only thing the device is capable of doing, just like any steering system, is changing the alignment of the front wheels
•    It does not change the length of any suspension element

The DDA is a management system because:

•    A conventional steering system moves the wheels in the same direction
•    DDA moves the wheels in an opposite direction – this is like changing the static toe angle of the steering system
•    A traditional steering system also changes the toe-in depending on the steering angle. (...)
•    DDA is a steering system that allows the driver to optimize toe-in and therefore steering response during a lap instead of having to change from one attempt to the next »

Mercedes specified that the device “ was not electronically controlled and had met all federal geometry and safety criteria ". According to them, the DDA “ benefits from the same implicit exemptions » provided for by Article 3.8 of the technical regulations as a steering system. The six-time world champion team finally recalled that it had warned the FIA ​​regarding the introduction of this new system, as required by Article 2.5 of the same technical regulations.

In their verdict, the commissioners considered that the DDA was indeed a management system, “ although unconventional ”, and that he was not part of the suspension. Nor can the system be “ accused of adjusting the suspension illegitimately », said the stewards.

Finally, as an integral part of management, the DDA cannot fall under Article 3.8, which excludes de facto steering systems. This is because the positioning of the front wheels affects the aerodynamic performance of the car and it is controlled by the driver. So any steering system would be potentially illegal without these regulatory tolerances.

Such a decision confirms Mercedes in its position as the big favorite this weekend and more generally this year.