Well, if you run just one client. it has no sense of rotating the mesh because is removed in anyway, but when they are 2 clients,(2 crafts on the World) and they are front to front, then you cant see none of them. but if they are back to back you see both. The camera is directed to the oposite Z craft axis.
About the definitions, well, front is the front of the craft (where the camera should be watching) and the rear is the rear of the craft (where the turbines are). So, the camera is watching from the center of the craft to the the rear part, thats the oposite Z axis.
Every client chose a craft from a list and when beggining the game the selected craft is sent to the sever to add it to a list of all the current players, this list os passed to all the clients on each iteration, so each client can see others crafts (this crafts are not being rotated but the code you game me is like not having written the code for rotating it)