Red Bull has revealed its drama on the grid at the British Grand Prix was caused by cracks being discovered in the rear-wing endplates of both its Formula 1 cars.
Red Bull mechanics were prompted in to a frenzy of activity pre-race to replace the endplates on both Max Verstappen's and Pierre Gasly's cars before the start of the race.
The matter was complicated by the fact that the cars were under parc ferme conditions until the start of the race, meaning the team needed permission from the FIA to replace the rear wing parts.
Asked by Autosport about what happened on the grid, Red Bull team principal Christian Horner said: "One of the mechanics doing one of the checks found a crack in the rear wing of Max, so we applied to get permission to change it.
"Then, there was an inspection on Pierre's and we could see the very start of a crack appearing in the same place. So permission to change them both was granted just as a security, and we did that."
As well as the endplates being replaced for ones of identical specification, mechanics were also spotted applying a special glue tape to the wings to ensure the cracks did not return during the race.
"The tape wasn't going to reinforce it, it was more some glue that went on," said Horner.
Both Verstappen and Gasly completed the race without any rear-wing problems, but Red Bull is likely to investigate why the cracks appeared in the first place.
The high-speed nature of the Silverstone circuit means the forces put through the cars are amongst the highest experienced during the Formula 1 season.