In our previous coverage of the 2026 active aero regulations, we looked into the mystery surrounding the Mercedes W17’s front wing. Video footage seemed to show the flaps taking up to 800ms to close – double the legal 400ms limit. I admitted that a simple hydraulic bypass trick wouldn’t work because the FIA Standard ECU monitors the transition in real-time. However, the story around this has just got a little more interesting. The FIA has officially launched an investigation into the Silver Arrows ahead of the Japanese Grand Prix.
Ferrari Demands Answers
The governing body didn’t just stumble upon this on their own. Following a dominant Mercedes 1-2 finish by Kimi Antonelli and George Russell at the Chinese Grand Prix, Scuderia Ferrari formally requested clarification from the FIA regarding the legality of the W17’s front wing. In English, this is Ferrari wanting to close a potential loophole discovered by the Brackley outfit.
So, how is Mercedes allegedly bypassing the FIA’s strict ECU sensors that should immediately flag an 800ms closing time? According to technical analysts and Ferrari’s inquiry, Mercedes has developed a highly sophisticated “two-phase” or “bi-phase” closing mechanism.
Instead of snapping shut in one single, fluid motion, the Mercedes wing splits the movement into two distinct stages. The first phase is a rapid movement that happens within the legal 400-millisecond window. Because this initial movement occurs strictly within the time limit, the FIA’s control system and sensors register the action as a “completed” closure.
However, a slower, secondary mechanical phase then follows. This delayed second stage allows the wing to settle into its final aerodynamic position long after the FIA’s sensors have stopped monitoring the transition.
The On-Track Advantage
Why go through all this trouble just to delay a flap closing by a fraction of a second? It all comes down to braking stability. When an F1 car slams on the brakes at the end of a high-speed straight, the aerodynamic balance shifts violently forward, reducing load on the rear axle.
By using a staggered, two-step transition, the Mercedes front wing increases front downforce incrementally. This prevents the front end from becoming overly loaded during that sharp forward weight transfer. The result is a smoother aero-balance transition, greater stability during initial braking, improved tire management, and more predictable handling into corners.
If the governing body decides this two-phase system violates the rules, they could issue a Technical Directive clamping down on the trick wing. This could be an interesting weekend in Japan.
