Gillette Fusion razors are allowed on planes but because the blade is so easy to remove from the Gillette Fusion razor it must be put inside your checked luggage.
So you can take a Gillette Fusion razor on a plane but only in checked luggage and not in your carry on luggage.
Disposable razors that you cannot remove the blades from can be taken on planes through carry on luggage but any razors that are not disposable and can have the blade removed from easy must be in checked luggage when boarding a plane.