Oct - Rcsoaring.com

The KW 100 awaits another flight. Hey, is that a Flamingoid off the KW left wing?Don Harris kindly donated severalhours of his time helping me programthe KW100 onto my JR 783XP. TomHoopes sent me some long emails withsuggestions. All it took was the advice ofthese two experts and several eveningsof my time, and I was ready to go. (I don’tthink the folks at JR anticipated a flyingwing with dual flaps and an adjustableCG when they designed the 783.)One control that didn’t need any work atall was the floppy winglets. Rol Klingbergdevised a set of winglets that are free torotate outward only. A metal pin stopsthe inboard rotation. The intended effectof the floppy winglets is to eliminateadverse yaw. When I did the math towork up the KW100 specifications, I wassurprised how small the winglets actuallyare: each one is only 17 ½ square inches,equivalent to a square less than 4 ¼" by4 ¼". My Zagis had more winglet thatthat.After getting the controls sorted out, Iwaited for slope weather.And while we are waiting for slopeweather, this might be a good time torun down the specs for the big wing. Roldidn’t include any specs in his lengthyinstruction manual, so these are from myown measurements:Span -- 100" in three segments: a 30"center segment and two 35" outboardsegments.All of the electronics, battery, and servosare in the center section. Pushrods crossthe joint-line between the center sectionand the wing-tips to run the elevonson the outboard sections. If you arebuilding a KW100 today you might wantto consider Harley Michaelis’ RDS driversinstead of long, exposed pushrods.Wing area: about 1000 square inches.Aspect Ratio 10:1All up weight as built by Tom Hoopes:71.8 ounces or 4 ½ pounds.Wing loading: 10.33 ounces per squarefoot. A wing loading calculator at www.silentflight.net says this means the stallspeed will be about 16 mph.The whole thing breaks down and travelsin box 36" x22" x 9".For comparison purposes, a Maple LeafDesign Icon is 130" in span, has a wingarea of 1150 square inches, weighs 69 to75 ounces and has a wing loading of 9.5to 9.8 ounces per square foot.The plane has a single towhook, andI ultimately learned it winch launcheswith no difficulty, once you learn how. Ithas a small plywood landing skeg nearthe trailing edge at the wing root, andit turns out this is the part of the planeOctober 2008 59