FIA Rules Mercedes F-Duct DRS Wing Legal

After complaints by Lotus and Red Bull, the FIA has ruled that the F-duct DRS wing on the Mercedes-AMG W03 is legal. This hopefully puts an end to controversy over whether it gave the team an unfair advantage. 

Lotus and Red Bull claimed that the F-duct violated Formula 1's rule against driver-controlled aerodynamic aids. In a way all the DRS systems violate this rule, given they are activated on the steering wheel, but it is deemed legal by the FIA. 

The FIA says that the system is passive and part of the normal operation of the DRS, and therefore, it is allowed. 

"It is completely passive. There are no moving parts in it; it doesn't interact with any suspension. No steering, nothing. Therefore I cannot see a rule that prohibits it," said Formula 1 Technical Director Charlie Whiting. 

The decision by the FIA means that the teams can either challenge the ruling or they are free develop their own similar systems.

Basically, the Mercedes wing works through an F-duct that opens when the DRS is activated. When opened, it creates a stall on the wing reducing aerodynamic drag and increasing top speed. This is useful in two settings. First, teams may qualify with the DRS open giving the W03 a top speed advantage. Second, it would increase the speed advantage granted by the DRS during the race making it easier for the W03 to pass. 

You can see images of the DRS open and closed in the gallery. 

Source: Autosport