I've been at it for about nine years now, and have four 40+ size planes flyable right now; each with it's own flight pack and engine. But use the same frequency on all, so the same transmitter (Futaba 6XAS). I also have three kits close to ready for covering, plus two planes being repaired. (And quite a few kits waiting.)
I have two electric flight packs with battery packs and motors (plus many extra speed 400, 05's and gear boxes), so I can have at least a couple small electrics ready at a moments notice; I have two additional flight packs for other planes being repaired. I have three OS 40FP's, (two currently on loan to my brother

), a 46 LA, an OS 70 Surpass, a YS 91 AC, two Magnum 52 four strokes, a Thunder Tiger 54 four stroke, a Super Tiger 61, a 91 two stroke (don't remember the brand), two or three OS 25's, a couple Norvel .061's, and a Saito 1.80 Four Stroke.
Oh yeah, I have at least 6 or 8 servos without homes, and just had a Hanger 9 Cap 232 ARF (73" wingspan) given to me, which is why I bought the Saito 1.80.
Anyone have an OS 1.20 they want to part with at a reasonable price? I need one for either my Super Skybolt or the Cessna 182. The other will get my YS 91.
No, I don't swap engines or flight packs.

Dennis-