Mercedes must prove T-wing is safe before Bahrain GP practice three

The T-wing fell off Valtteri Bottas's Mercedes in Friday's second practice and caused damage to the floor of Max Verstappen's Red Bull.

Given that this was Mercedes' second such incident, following a similar one in China, the FIA has taken it extremely seriously.

Mercedes has worked overnight to strengthen the T-wings, and the team now has to prove "beyond reasonable doubt" to the FIA that the fix can guarantee there will be no repeat.

If technical delegate Jo Bauer is not satisfied, then the FIA will ask Mercedes to remove the wings.

In the unlikely event that the team contests that decision, the FIA has the option to refer the matter to the stewards as a case of "dangerous construction".

When Lewis Hamilton's car was pushed to the FIA scrutineering bay on Saturday morning for the team's own usual pre-session checks it was missing its T-wing, although that may have been because the fix was still being completed.

Frustrated by the damage caused to Verstappen's car, Red Bull boss Christian Horner called on Friday for the wings to be banned.

The Haas team was told to remove its T-wing during Australian GP Friday practice before it got clearance to refit it in revised form next day.

Haas team principal Gunther Steiner said it should be down to individual teams to prove their T-wings' strength and that a ban would be excessive.

"There were parts lost before [from cars] and the FIA has to sort out with Mercedes that they fix their problem," said Steiner when asked by Autosport about the calls for a ban.

"I have nothing to say about them because I have no idea why it failed, so they have to explain that to the FIA, then the FIA will take a decision.

"We could say this about every part. How many people lost a wing? We were among them last year and we didn't ban front wings, we fixed them.

"Last year, Toro Rosso had a few issues with the wheel rims, but they didn't ban the use of rims, they fixed them.

"It's the same. Just because it's a T-wing and somebody says they don't like them doesn't [mean] we need to take them off.

"The FIA will take a qualified decision of what they want to do."

Steiner also pointed out that when Haas was told to remove its T-wing, it had never suffered a failure like Mercedes' in China and Bahrain.

Haas achieved its fix in the short term by gluing a carbonfibre strip to either side of the shark fin engine cover, which minimised the vibration being transferred to the T-wing.

The Mercedes T-wing Bottas lost differs from that of Haas in that it is mounted independently of the shark fin engine cover.

The FIA has indicated T-wings and shark fins will both be banned for 2018.