wynterhwk

Greetings

I am building a Great Planes Easy Sport 40. I have it almost fully framed and have done enough to mock it up. The horizontal stab is just the smallest bit out of line with the main wing. It really is just a scoch. The thing is the stab fits nice and tight in the fuse. If I sand to level the stab, I also loosen the glue joint...so....do I leave it alone for the sake of frame strength or is it important enough to adjust. Also, I would like to leave the dorsal fin off.... I like the looks better....will this affect the performance of the plane? Any help would be greatly appreciated.

Paul

gubbs3

My Feedback: (1)

By dorsal fin you mean rudder, right? You can not fly without the rudder. Most of all you would have no control over the plane on the ground once the tail is up and it would most likely spin and you would break something. Also, if you ever got into a spin, you would be unable to recover, resulting in a re-kitted plane. Leave it on. End of story.

majortom-RCU

My Feedback: (40)

I have seen plenty of models fly quite well enough with very noticeable mis-alignments. They lose just a little bit in terms of competitive performance, if you are intending to compete with it; but if you are sport flying, I would just cover it and fly it. You'll very possibly never notice the difference, nor will anyone else.

Last summer I flew a quarter scale I picked up at auction, loaded and ready to go, and had it in the air for a full flight, then noticed when it came down that the rudder (fixed vertical fin) was never glued into its slot. The only thing that kept it from falling off was a little bit of friction and the linkage. I did wonder when I was flying it if it had a little slop, but since it was my first flight on that bird, I didn't know any better, and it basically flew where I wanted it to go, and landed with no complications.

By dorsal fin, I expect you mean the little projection out in front of the vertical fin itself. I think my recommendation would be to simply add a quarter or half inch stick along the front edge of the vertical fin, to make up the difference in area of leaving off the so-called dorsal fin. This is another item that you'd probably never notice the difference by just leaving it off, but when you have the opportunity to compensate for your mod, I would prefer to honor the kit designer's intentions.

buzzard bait

I gather you intend to attach the main fin that the rudder attaches to, but leave off the fin that is more horizontal and angles up from the fuselage to the lower part of the main fin. If that is the case, you can leave it off, bearing in mind that the plane may or may not have a little less directional stability. It's probably not enough side area to matter if you don't have it. You can tape on a bit more fin or rudder area as an experiment to see if you think the extra area makes a difference. If you like it, then you can add some material to make the fin bigger or add to the rudder to make it bigger. It probably won't matter, but side area is pretty easy to add or subtract. I don't think the shape matters much.

Jim