On a recent build of a Ultra Sport 40+ (US+)I decided to lengthen the fuselage by 3 inches. I wasn't sure of the results of this until I was through and put it in the air. One reason I wanted it longer was that I was planning on putting a Super Tiger 90 on the front which I did. I initally thought this might be too long for a 40 size airplane and started to only go for 2 inches but didn't. I knew that the torque of the 90 needed this extra leverage to keep the plane tracking true on uplines and wide open pulls. It also needed the leverage to balance without lead. With these two things in mind I decided to give the three inches longer fuse a try. One way of looking at this is the fuse would be about the same lenth of a 60 size plane with 40 size flying surfaces. WoW what could be the outcome. Well some of the lightness freeks will say it is a bucket of lead that will have negative atributes, possible. Will it be easy to do during the build? It is easy with a little planning if you have building experience. THe plane, Ultra Sport was a prime candidate for this alteration/modification because it is no 3D airplane even though it will do some. The US+ lives up to its name as I believe it is one of the better sport planes out there. I will fly slow or fast and will really cut up with the use of the rear controll surfaces because they are rather large compared to the aileron surface area and will make the airplane go wild in the air. Ok enout about this kind of stuff, How does it fly. Well I can say Great! The plane flys very much like a pattern plane under full throttle flight. It will really move along with that 90 on the nose. How is the landing? It lands very slow and seems to like to land with one clik of throttle until just before touch down. How is the aerobatics? Not a 3D plane but very respectful manouvers can be had but you probally won't want to try slow rolling harriers etc. as the ailerons are a little small. Sure the weight has an effect, knew that from the get-go, didn't care because I didn't plan on trying to turn it into a 3D pane. I wanted this plane for sport flying on Sunday afternoon if you know what I mean. A plane that you can throw in the back seat on moments notice and head out to the field for flying, the kind of flying most of us do or are capable of doing. I bet some of you have done some of the same kind of modifications on kits, if so lets hear how it went so other might gaine some knowledge here.

Buzz, I had, with a captial H, a Laniar Explorer 40 trainer. It never flew right. On approach one day a few months back, I got way off line and decided to go right for a go around vs trying to go left which would have brought it over the pits. My instructor thought I was going to hit the power lines, so he grabbed control and tried to go under them. At slow speed, a little down elevator was way to much and he tagged the top 2x6 on a rail fence. Photo below.

The wings and tail were in OK shape, so I built a stick fuselage using the wing and tail. The trainer required a lot of weight under the engine, so I decided to stretch the nose a bit, so I added two inches there. The elevator didn't have any control at landing speed, so I increased the size of the elevators by about 15%. At the suggestion of my instructor, I also added three inches behind the wing. What a difference. I flew it for about a month or so and then lost it in the creek behind the field. I'm not sure just what happened, radio, structural, ???, but it went in like a lawn dart, right into the thickest part of the creek bed, never to be seen again.

I liked that plane so well that I sat aside a 4*60 I was building and built a clone of the one I lost. I had bought a spare wing kit for the explorer, so it was not a big project. I did cut the length ahead of the wing back by 1/2". I needed about 2oz of lead under the engine before, but now there no lead required. It balanced just fine with just a minor move of the battery. I also increased the elevator size a bit more. All I can say is that it is a real pleasure to fly a plane that does what you tell it. I get a lot of comments on it at the field. "Who makes that one". I decided to call it the Rogers phase II.

Wow, looks like a great plane, Campgems. Good to see that I am not the only one out there with a brain and willing to use it. So many people try to immitate the 3D crowd so that they can't get the point of sport flying.

I took my Ultra Sport out this afternoon and flew it for 30 minutes and it sure is sweet. The three extra inches seems to be a good choice for me it takes off fast and straight even when I lift off quick without much air speed. I was running a 12X8 on the Super Tiger 90 today and it pulled it very well. Not many people I have talked to have experimented with lengthing the plane but if you think about it the pattern planes are long and fly straight and true so why not take advantage of this on a sport plane. I experimented in flight trying knife edge and different tracking position and it seemed real good and stayed pretty much where it is placed. Still am not sure which prop the 90 is going to pull the best with and have several more to try like the 12X10 and 13X8 but I can't complain with the 12X8 or 13X6 so far. I am running slobbering rich but it is still pulling like a champ.

I was out to the field today and, well as they say, a photo is worth a 1000 words. Now, after building two fueslaes to fit wings I had, I need to build a wing to fit this fuselage. I'm thinking that I might go with a Sig four star airfoil and a little less dhideral. I just got my four star finished and flew it on Friday. Looks like it is now my new "main plane"

Don

If everything else stays the same, lengthening the fuse increases stability in pitch, so you could experiment with moving the CG back. Might make it even nicer. Jim

I flew the four star today. It is really responsive, and once I cut the throws back on the aileron and dialed in some more expo on them, it is a realy nice plane. It doesn't handle like the one hanging on the fence though. It has more torque twist on take off, and the tail wants to jump up as soon as you start rolling. I could run the one on the fence up to full speed before rotating and lifting off. The 4* just wants to be in the air. I need a bit more work on take offs before I am as consistant as I was with the fence bird.

The longer fuselage on it made quite a difference. The fuse on the fence bird is the same spinner to aft end of the rudder as the 4*, the wing is 60" vs 72" and the cord is a lot longer on the 4*. To get the same ratio of length to ws on the 4*, I would need to add another 6 to 8 inches to the fuselage. That could be an interesting bird. I'll see what happens, if I have to do a rebuild.

Don

One of the neatest things about RC airplanes is that we can experiment with designs to see what effect it has on it's performance. One thing enjoy, is to take a plane that has nasty habits, and try to "make it better" sometimes it works and other times it is futile, and all you have done is made more scrap wood for the fire....