Take this one with a very large grain of salt. While I'm sure they meant well in putting this together, critical thinking sort of escaped them. Of course, they couldn't be expected to realize that no plane was going to be able to overcome several box steel columns, backed by 52 inch steel spandrel plates, which are themselves braced up against 4 inch concrete slabs on steel pans supported by the floor trusses bolted and welded to the core. So any "complete penetration" would have to be an illusion created by using explosive charges. Obviously no remote system could be relied upon to strike the prepared area properly. Only a CGI can do that.
9/11 Ten reasons why the hijackers were fake.