The Trouble with Profile Planes By James Goss      When I first saw a profile plane about ten years back I thought it was a strange looking plane and that someone couldn't afford to build the whole plane. It looked a lot like a control line plane and I never did get efficient in the art of flying those. At the time I didn't have any idea that I would grow to love these crazy looking planes as much as I do today. I have built many of them in the past and I am involved with several on the building board at this time. I guess some of the main reasons for liking them deals with the way they are built. That flat fuselage is easy to build and uses less material compared to a conventional fuselage. The wing is no different form any other wing; the same building techniques are used as in regular models. I really like the low wing loading; most of my profiles weigh less than five pounds with a few at 7 lbs.      Most people look at a profile plane and think they are really fast to build and they are to a degree, especially if you cover the fuselage before you mount the wing. I do not prefer to cover the fuselage before mounting the wing, I like to install the wing, get a good glue joint between the fuselage and wing, and then cover the whole plane as a unit. I think you will get a more pleasing finish this way because the covering on the fuselage and wing will blend together and lines will not show as readily. It does take a lot more time this way but it is worth it to get a quality covering job. Who would have thought that a profile could take longer to cover than a conventional plane?      What I really like the most about profile planes is the accessibility that you have to all the components. Having the fuel tank visible makes it really nice to check on your fuel level in a low fly-by and also for troubleshooting. In the past I always placed the servos inside the wing, but now I mount then outside the wing, which is much faster and also allows easer troubleshooting. The receiver and battery pack still go inside the wing under a hatch cover plate on the bottom of the wing. One thing that I would recommend is to place your on-off switch on the top of the wing instead of the bottom. You will find that it is much easier to access it that way. If you place it on the bottom of the wing it is harder to find and in some cases you must pick the plane up to activate the switch. Also double the wall thickness of the ribs that are on either side of the battery. With the many crazy maneuvers we do with these profile planes the battery really gets thrown around so have it secured so it can't go through the ribs. I have had this to happen on two of my profile planes.      I could go on all day talking about what I like about profile planes, but what I really wanted to tell you about in this article is a common trouble we have with profile planes. The fuselage tends to break at a point just rear to the wing when you have a mild crash or hard landings. You will see a wrinkle in the covering form at this location, which is an indication that the fuselage is cracked. Usually a little thin ca glue will give you a temporary fix and keep you flying for a while, but it will break again. The question is do you build the fuselage solid or do you stick frame it? I have used both methods and like the solid the best. It does weigh a little more but by having it solid it allows you to use some pretty good techniques to add more strength to it. One is to laminate the fuselage out of two sheets of balsa instead on one. I like to use two 3/16 sheets and laminate them with a heavy fiberglass cloth and epoxy resin in between the two sheets. Be sure to use epoxy resin because it is not brittle like polyester resins are and will take more bending before breaking. This also helps out with another problem, warping of the fuselage. If you build the fuse from solid balsa it may or may not warp as the humidity changes from day to day. The fiberglass seems to help in that area.      The latest technique I have started using to strengthen the fuselage is to install a piece of 5/8 inch channel aluminum down the length of the fuselage about midway of the wing back to the tail. The channel aluminum will not allow any side motion of the fuselage while under load and only adds about three ounces of weight. The fuselage that I am now building weighs 1 pound and two ounces. To install the channel I cut a 5/8 slot into the fuselage and use epoxy to glue the channel in place while it has 120 pounds of weight on top of it and is resting on a very straight work surface. I feel that the aluminum channel adds more strength than other material such as hard wood dowels or hard wood in general. I will probably stay with this technique in the future because it seems to be one of the best methods I have come across. With the large engines I am now using on profile planes in order to get good hovering capabilities the fuselage must be able to handle that extra power.      So if you plan on building a profile plane in the future be sure to give it a strong fuselage. If you have never flown one of these planes you don't know what you have been missing. You will try some of the maneuvers with these planes that you would never have thought about trying with your more expensive planes. Even though they are cheaper you will still get attached to them. Flying low to the ground and doing 3-D maneuvers it is only a matter of time before the ground gets in your flight path. Go ahead and build two while you are building so you will have a backup profile.