Plug-in vs one piece wings are not a legal issue---more a personal choice. As Rich has said, the majority of Daddy Rabbits, (the single most popular plane in SPA), have them, and the World Models Intruder, (also very popular) can be built with plug-in or a one-piece wing. A wing tube is included with the kit. I learned in my article research that the first plug-in wings go all the way back to the mid-'60s, (ie the Simla).[X(]

There are also a number of different ways to secure plug-in wings that people debate back and forth.

Duane