Both Red Bull cars were found to be infringing the technical regulations in post qualifying scrutineering, flexion of the Front Wing flaps being the culprit. Followers of the technical side of the sport might be thinking here we go again... however it's not aeroelasticity at blame this time (contrary to Christian Horner's rebuttal with the BBC, although he did later concede they'd thinned the metal used) but a metal component that was 'designed' to deform or spring under load.
Article 3.15 of the technical regulations covers aerodynamic influence:
No part can be infinitely rigid, especially given the forces a Formula One car has placed upon it. That's why key areas of the car, known to be influenced by the teams to make aerodynamic gains are tested for deflection. The most well known of these tests is the front wing deflection test, owing to the flex teams were trying to achieve in the preceding seasons. In those circumstances the teams were trying to either arch the wing back, twisting it about the front wings pylons (longitudinally) or flexing the far tip of the wing, in order for it to be in closer proximity to the ground. The front wing deflection test has been beefed up over the last few years in order to make it difficult for the teams to 'flex' their wings with it now set at a vertical load of 1000nm over the endplate.
The flaps are not subjected to the load test and so they're free game for the teams to exploit. We've often seen the Williams front wing deflecting at high speed but theirs is simply being achieved through aeroelasticity, ie the force on the wing is sufficient for it to flex downward as the load increases. It's been an exceptional tool for Williams this season but doesn't only have a direct effect at the front wing but components downstream too.
This early iteration of Red Bull's front wing had the adjuster placed much further inbound than it's most recent locale, furthermore it also adjusted the whole flap, whereas we can see in the wing used from China onward the flap had been split into two sections, with the outer section of the flaps retaining their AoA and therefore a consistent airflow structure with which to manage the outer tyre wake, whilst the inner most section of the flap moved around the metal structure that defines both sections.
The FIA in my opinion have done the right thing here, as a dangerous precedent gets set when teams start to push the boundaries of the regulations. Things like this start off small but then become much larger concepts, nipping it in the bud at the final round means teams won't put huge resource into developing their 2015 challengers with this in mind, although as we know they won't forget it and will find another way. What may appear to be fairly innocuous at the outset often descends into a complex and expensive chase of performance, take FRIC as an example...
It'll be interesting to see if the FIA devise another deflection test for the flaps going forward and/or how much the teams make an effort in their quest to increase their aeroelasticity. For me Williams have perhaps showed the way in this regard this season (front wing flap deflection) and have specifically targeted direct and vicarious downstream gains from it. They clearly lack peak downforce when compared to even some of their close rivals, let alone Red Bull & Mercedes but they've proven there is more than one way to skin a cat, with an extremely efficient car. The deformation of their front wing flap, falls inline with the compression of the tyres at speed, which in turn changes its wake profile. This means that the aero structures around the floor and sidepod also change with speed (mass airflow) and so being able to manipulate this flow through flap deformation will have a marked effect on top speed. Furthermore it also changes the cars centre of pressure and so controlling how this pressure shifts also makes life easier for the driver in terms of balance (under braking, turn-in etc).