[GentleKiller]

My squad and I have tested the Spit MkI online and it worked perfectly. As spud stated, everyone must have the mod and Spit installed. Think about it.....if they dont have the plane model installed, how are they going to see it?

yes true
unless you want to tell your people, armee, in the rules of your mission brief for a website to get mods, so more people will get the same plane, in this case spit mk1