New flexi-wing tests are not due to be introduced until after this weekend's Azerbaijan Grand Prix, but there has been unease from some outfits about the potential benefits rivals could get one last time on Baku's long straights.

On one side are teams like Mercedes and McLaren, which are adamant they are not exploiting the 'bendy' wing phenomenon. Then there are squads like Ferrari, Red Bull and Alfa Romeo that have been pushing the boundaries with their cars this year.

Plus the FIA is already taking a closer eye on things too, with teams having been instructed from this weekend's race in Baku to add locator dots on their rear wings which can be used to check on how wings are flexing at high speed.

As the above photograph shows, and in order to get further insight into what the teams are achieving whilst out on track and have a baseline for when the new test procedures come into force, the FIA has instructed teams to place 12 10mm dotted stickers on the rear wing.

These stickers will act as datum points on the rear wing for when the FIA review the footage from the rear facing cameras and give them an extra weapon in their fight against the teams who are believed to be circumventing the current static load tests.

This visual confirmation of flexion or rotation is a tactic that we’ve seen deployed by the teams themselves down the years, as they’ve placed chequered stickers on their front and rear wings and used hi-speed cameras to capture any deformation.

Williams FW38 front wing detail with a deflection tester

Photo by: Giorgio Piola

Flexi wing history

Flexible wing controversies are nothing new in F1 though, as cars designers have long looked to shed some of the drag created and boost straightline speed.

This has led to the FIA having to move the goalposts in order to counter the ways in which this is achieved, with teams operating in a grey area between what is measured in the static test during scrutineering and what can actually be achieved out on track.

This imperfect science is why the FIA opted to give teams a grace period in which to come in line with the new load tests that are being introduced from the French GP.

Teams are being given a 20% tolerance in the first month, in order they have enough time to comply with the full intent of the new tests.

However, with the championship race being run exceptionally close at the front, it's no surprise that title protagonists Mercedes and Red Bull have started to eye one another, and talk of a protest has loomed large.

The FIA pull-back test that emerged in the late 90s was as a result of the teams pushing the boundaries and the governing body needing to find a way to keep them in check.

The tilting wings being used by the teams at the time led to several accidents, as the wings failed, causing the car to lose downforce and then career off the circuit, leaving the FIA no choice but to intervene.

Rear wing flap pullback test

Photo by: Giorgio Piola

To keep the teams in check, the loads and the way they're applied have changed down the years too, as the FIA reigns in any attempts to rotate the wing and improve performance.

In this respect, the technical directive issued to the teams after the Spanish Grand Prix was more of a notice, making clear that the FIA is closely monitoring the situation and that it intends to use the provision in article 3.9.9 of the technical regulations to amend the load and deflection tests to reduce the team's ability to rotate the wing out on track, even if it can pass the tests during scrutineering.

Article 3.9.9 of F1's technical regulations states: "The FIA reserves the right to introduce further load/deflection tests on any part of the bodywork which appears to be (or is suspected of), moving whilst the car is in motion."

Rear wing deflection test

Photo by: Giorgio Piola

In addition to the deflection tests already outlined in the technical regulations, the FIA has now added a rotation component, with a one-degree tolerance when a 750N load is applied 20mm forward of the leading edge of the rear wing endplate and 1000N load is applied 350mm behind the rear wheel centreline, 890mm above the reference plane and 300mm from the car centre plane.

The governing body has also made it clear that it will continue to monitor footage captured by the onboard rearward facing cameras to ascertain that the rear wings are not using non-linear deformation in order to pass the new tests.

Should it feel that the tests need to be tweaked or additional tests added, it can once again invoke article 3.9.9 but this will be a costly exercise that everyone will be looking to avoid.

A new front wing for Lewis Hamilton, Mercedes W12

Photo by: Steven Tee / Motorsport Images

But it's not just rear wings under the spotlight, because the behaviour of the Mercedes front wing has also been singled out by Red Bull.

Red Bull team boss Christian Horner said in Monaco regarding the controversy being centred around his outfit: "I think if the camera was facing the other way on our rival's car, we would be having the same discussion."

This, after all, is an area that Red Bull has a great deal of experience in, as it was dragged over the coals on several occasions during its championship winning years.

The load and deflection tests were altered during this period to deal with the various ways in which teams were using flexibility to improve performance on track whilst passing the prevailing tests.

Recent footage of the front wings seem to suggest that the flaps are tilting back excessively under load and returning to their ideal position during the braking phase.

This will not only alter the overall load on the wing, but it will reduce the drag and also change the wing tip vorticity.

As we see at the rear of the car, this is not a solution that's found on just one car either, with most of the field using the effect to improve the cars 'aerodynamics.

So, any changes made by the FIA will be costly for almost all teams in terms of redeveloping their designs. Any forced change would need to be weighed against the cost cap restrictions.

This could require resources to be diverted away from any planned upgrades and, given the quantity of teams pursuing this development direction, the overall pecking order might not be dramatically affected either.