Plane file refers to missing Component Frame '~CS_LEFTSKID_GC_Back'
Plane file refers to missing Component Frame '~CS_LEFTSKID_GC_Front'
These thing are a little box you have to place in the Skid.
One at the front and one at the back side of each skid.
The boxes tell's G3 were the Skid have the contact point's to the ground to avoid a sinking helicopter. (half of the skid is under the ground)
I also have the problem with my first heli.
This is the only component wich isn't explaint in the tutureal, and is difficult to locate at the demo helicopter fom Knifeedge if you don't know were its location is.