It seems like there are a couple of big perpetrators of this stuff... All Asian outfits of course...

Fly Models seems to be the most egregious violator. Every Fly Model's plane comes with partially photocopied manuals from other manufacturers...

Case in point the Ultimate 40S which NP, Texas-RC and many others sell....

It's a "Fly Models" or "Evergreen" plane, and it uses the same manual as the World Models ( another Asian manufacturer ) plane even though the two planes are actually distinctly DIFFERENT and have few similiarities!

In turn this causes confusion for the builder, who cannot find the pictured structures or parts.

Fly Models planes are carried by many U.S. Vendors and I've seen their planes stocked in Mom and Pop LHS'...

Of course the Yak, Sig and other planes are ALL ultimately coming from Asian factories, so in effect the manufacturers are hurting themselves with these practices.

If they rip off a design ( as in QueQue's plane ), and/or manuals, then the next time someone wants to put a new product out, that will be a manufacturer NOT selected to do the production... so they ultimately loose....