There were no planes on 911, only 3D holograms of planes, which is why some people filmed planes and other couldn't of the event because it depended on the recording angel. There was however landing gear from another plane next to the discovered passports that had been ripped off of another plane by heavy machinery but it wasn't grey but actually white with orange stripped markings. The more you know, and that is coming from a ground zero worker witness of it.