Fixing buckle comprising: - a first securing part provided with a first coupling means, - a second securing part provided with a second coupling means defining a hook, the hook being configured to collaborate with the first coupling means so that the first coupling means is attached to the second coupling means in removable manner, - a blanking system (7, 8) configured to define a first position preventing extraction of the first coupling means from the second coupling means and a second position allowing insertion and extraction of the first coupling means, the blanking system (7, 8) comprising: ∘ a first blanking plate presenting a first position configured to at least partially obstruct the hook and prevent extraction of the first coupling means from the second coupling means, and a second position configured to allow insertion and extraction of the first coupling means, ∘ a second blanking plate presenting a first position preventing extraction of the first coupling means from the second coupling means by at least partially obstructing the hook, and a second position for insertion and extraction of the first coupling means, fixing buckle characterized in that: - the first position of the first blanking plate is configured to prevent movement of the second blanking plate from its first position to its second position, - the second blanking plate separates the first coupling means and the first blanking plate along an extraction channel defined by the hook. - a first securing part provided with a first coupling means, - a second securing part provided with a second coupling means defining a hook, the hook being configured to collaborate with the first coupling means so that the first coupling means is attached to the second coupling means in removable manner, - a blanking system (7, 8) configured to define a first position preventing extraction of the first coupling means from the second coupling means and a second position allowing insertion and extraction of the first coupling means, the blanking system (7, 8) comprising: ∘ a first blanking plate presenting a first position configured to at least partially obstruct the hook and prevent extraction of the first coupling means from the second coupling means, and a second position configured to allow insertion and extraction of the first coupling means, ∘ a second blanking plate presenting a first position preventing extraction of the first coupling means from the second coupling means by at least partially obstructing the hook, and a second position for insertion and extraction of the first coupling means, ∘ a first blanking plate presenting a first position configured to at least partially obstruct the hook and prevent extraction of the first coupling means from the second coupling means, and a second position configured to allow insertion and extraction of the first coupling means, ∘ a second blanking plate presenting a first position preventing extraction of the first coupling means from the second coupling means by at least partially obstructing the hook, and a second position for insertion and extraction of the first coupling means, - the first position of the first blanking plate is configured to prevent movement of the second blanking plate from its first position to its second position, - the second blanking plate separates the first coupling means and the first blanking plate along an extraction channel defined by the hook.