WRIGHT
BROTHERS Aeroplane
Company
Veteran model designer/builder Pat
Tritle tells us how he developed a radio-controlled, electric powered
scale model of the 1903 Wright Flyer -- just in time for the Centennial of
Flight!
By Pat Tritle
The design began using the Paul Matt 3-view drawings. In studying the drawings and planning the model design I decided that to be suitable for the average builder the model would have to be kept as simple as possible. As a result, I decided to control the model using the canard, rudder and throttle rather than wing warping which in itself would have complicated the design beyond my original goal. I have always felt that flying quality should take priority over accuracy in outline. The power system would also need to be simple and reliable. For that reason I chose to use two geared electric motors operating through a single electronic speed control. Unfortunately, reverse pitch props are not available, so counter rotation wouldn�t be possible unless the builder opted to carve his own props. Micro servos were used to operate the rudder and canard. I also knew that to turn the model without warping the wing, the wing would need a small amount of dihedral. Lastly, I opted to build the wing centerline on center rather than with the asymmetrical centerline. Within those parameters, the overall scale outline and airfoils would be retained for initial flight testing. Flight TestingThe first test flights proved to be a dismal failure. The model was hand launched at full power and flew right into the ground! Repairs were made, including the addition of a more positive canard neutral point and the second attempt was made. The result was the same as the fist. After several small changes to the basic set-up, including altering the balance point and lengthening the fuselage, it was obvious the model was not going to fly, and at this point the prototype was battered beyond further repair. Fortunately, the first three attempts to fly were video taped. With a careful review of the video I determined that it wasn�t dropping the nose, but the wing was actually over-flying the canard causing the downward angle of attack, so a new prototype was build using a flat bottom airfoil rather than the scale under-camber. The airfoil on the canard was changed to a deeper under-camber in an attempt to equalize the lifting ability of both the wing and canard. At this point I still had a bad feeling about the overall design, so I put the R/C model aside and built a 1/3 scale glider model of the R/C model.
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![]() Pat displays his RC model Flyer.
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Testing the Concept Using a GliderInitial test flights on the solid balsa glider model proved to be very inconsistent. After several changes in the canard angle and CG (Center of Gravity) the model still proved itself too inconsistent and unstable to be practical. The next step was to increase the canard span and chord 25% and relocating the CG back to its� original location. That turned out to be the solution to all of the Flyers� ills. From that point on, the Flyer was as stable and honest as any other glider I�ve flown in its� size range. So, the changes were incorporated into the R/C model and flight testing resumed. Success at Last!The first test flight on the new prototype proved to be as successful as anyone could hope for! The model was very sensitive to pitch control but trimmed easily for level flight and turned well on the rudder. The power system proved adequate, and when trimmed properly would fly nicely at 2/3 power. Do to the nature of the "Flyer", I didn�t attempt any maneuvering beyond gentle turns in both directions. As a result of prop torque, the model turns better to the right then the left, but is very controllable in either direction. After 20 or so test flights making minor changes I determined the model to be ready for the average modeler to build and fly, and to prove the point, a third prototype was built. The third model actually flew a bit better then the second, only because more care was taken to insure the model was straight and true. Looking BackLooking back over the course of development of the model, it occurred to me that this was without a doubt, the most challenging and rewarding design I have ever been involved in. To have the opportunity to work with this design really brings to mind what the Wright Brothers had to overcome to accomplish that first powered flight almost 100 years ago. |
![]() Pat worked the bugs out of his RC Flyer design by building and testing a gliding model.
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You can see Pat's 1903 Wright Flyer replica at the Dayton Air Show on July 20 and 21, 2002. They will be our honored guest in the Wright Brothers Aeroplane Company tent. To find out more, click HERE. |