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Will adding weight make my glider fly better in wind?

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Will adding weight make my glider fly better in wind?

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Old 11-08-2018, 06:34 PM
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cjtyped
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Default Will adding weight make my glider fly better in wind?

i have a scale powered glider. Want to compete in contests, but wind affects the plane. So if I add weight but not change the CG, will this help? Any other suggestions?
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Old 11-08-2018, 07:02 PM
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How does wind affect the glider?
More mass or weight increases the inertia of the plane, which means the sane force of wind induces a smaller acceleration or chage of speed (side-side and up-down).
If the mass is centered, it will not change the reaction of the glider to wind-induced rolls, yaws and pitch changes.
Increased weight also forces the plane to fly faster in order to generate increased lift to compensate, increasing the stall speed some.
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Old 11-08-2018, 07:28 PM
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I would like to know more about your specific glider. Also by contests are you referring to ALES?
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Old 11-09-2018, 09:15 AM
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My plane is a Mick Reeves' designed Fournier RF-4 powered glider. It has a 10'. Wingspan. Electric powered. The usual aileron,Rudder,elevator,throttle plus a retracting belly wheel and spoilers. It came out pretty good, modeled after one in Las Cruces,NM. I know if I want to fly in contests, I need to be able to handle differing wind conditions, hence the question.
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Old 11-09-2018, 01:35 PM
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The current ALES and F5J type sailplanes are slightly larger but average around 65 oz RTF. We usually do not start adding ballast until the wind hits about 15 mph. My ALES sailplane weighs 80 oz and I have never added ballast and have flown in 25 mph winds. I think yours is a bit heavy to start with but you also have more fuselage surface drag. Your not really going to be very competitive with what you have so I would say no to any ballast and suggest you just fly it as best you can and have fun.
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Old 11-09-2018, 06:04 PM
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I need to clarify more. I am planning on entering Standoff Scale contests with my Fornier. That's all. I am going to try adding weights to my plane, bit by bit, according to wind conditions.
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Old 11-09-2018, 06:38 PM
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I wouldn't bother if I were you. The main reason why weight is added to sailplanes is that it does help with penetration. What this means is that the sailplane is able to travel farther out while searching for lift in windy conditions. For your application, there would be no benifit.
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Old 11-10-2018, 04:42 AM
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Originally Posted by cjtyped View Post
My plane is a Mick Reeves' designed Fournier RF-4 powered glider. It has a 10'. Wingspan. Electric powered. The usual aileron,Rudder,elevator,throttle plus a retracting belly wheel and spoilers. It came out pretty good, modeled after one in Las Cruces,NM. I know if I want to fly in contests, I need to be able to handle differing wind conditions, hence the question.


Is it the 1/3 scale or the 1/4 at 110 inch wing? I ask because you mention a 10 foot wing and the 1/3 scale on his web site is 12 foot while the 1/4 is just over 9 foot. What does it weigh now? Mick shows the 1/3rd coming in around 22-24 pounds and the 1/4 at 10. Might e-mail Mick and ask him. Go through the contacts page on his web site. He responds in a day or two.
Mick Reeves

And what kind of wind conditions are you talking about? What wind speed? Steady? Gusty? At the ground or higher up?

Adding weight to a glider/sailplane is a common practice. It improves penetration especially in rough air. Real and model both do it all the time. The full size competition guys use water ballast as do many larger models. I have a Lengionair 140 (from the 70's), 140 inch wing, which is designed with aluminum tube spars intended to carry extra weight in the form of .44 / .45 caliber lead slugs. It shows that on the plans and in the instructions.

As mentioned, you might find a need for a little higher flight speed. But being a Motor Glider, that should pose no problem. I do know Mick has really put the design through its paces doing hard loops and rolls with it so did you build it according to his plans? Keep in mind that a lump of added weight directly on the CG will focus more stress to that part of the structure. Just make sure the air frame is up to it. And it will float forever on final if your idle is set too high. But yours being electric shouldn't have that problem.

Depending on the scale you have, I'd say add some weight and see how it goes. Just a bit to start with. Then work up to what suits you. But again, contact Mick. I have no doubt he will respond with some interesting info on the design.

Last edited by Appowner; 11-10-2018 at 04:44 AM.
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Old 11-10-2018, 07:19 AM
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To be honest, after watching this video I would not consider it a sailplane by any definition. IMO there is not going to be any benifit to increasing the wing loading of an airplane that already has a high wing loading.

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Old 11-10-2018, 07:25 AM
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This is a much better example of a powered sailplane.

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Old 11-10-2018, 08:43 AM
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You guys need read the ops posts. He is not competing in an actual sailplane event such as time, task etc. but wants to compete in a scale competition. Since scale judging has a requirement called realism he is probably concerned with penetration so scale flight in less than ideal wind conditions can still be simulated. In this case ballast will be the answer but you need to try this with little or no wind up 3 mistakes high and discover what if any are the changes in stall and flight characteristics. By all means add weight in smaller amounts until you reach a comfortable medium. I have a hanger nine Pawnee of the first generation that was so lightly wing loaded that it was difficult to land in anything but a light wind. The flaps actually made it worse. I tried moving the CofG but that did little to smooth the plane out at low speeds on landing. I found that filling the wing tube with a lb and a half of lead right on the CofG settled the plane down and now it lands perfectly in breezy conditions and has become my new loaner plane for visiting pilots.

We also have a small man made hill locally that can be sloped but only when the wind is right on the hill, brisk and steady. I bring my Sophisticated Lady and Gentle Lady and with ballast they are able to handle the wind without getting blown over the top. You have to be ready to ballast to the conditions and live with the changes in performance.



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Old 11-10-2018, 09:19 AM
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Sorry but we have had this discussion before and you know that I just don't agree. Having a powered airplane that copes with the wind well has more to do with the setup then wing loading. The subject airplane in this thread is a powered airplane with a pseudo sailplane wing. Wind is nothing more then airspeed increase to an airplane in flight. If your airplane is set up to have different trim settings at different air speeds then yes wind is going to be an issue. Will more weight help the situation? In a bandaid sort of way yes. It will take more wind force to make a change but it will also require larger control inputs to correct. Once an airplane is set up so that the CG, thrust line, incidence control throws, differential etc are all in balance the airplane will handle the wind much better. Adding weight on a powered airplane is nothing more then a coverup to a bad setup. Case in point, on a dual aileron servo setup, how many guys take the time to actually measure the aileron movement and go into the separate channel ATV and adjust them for the exact same deflection? Most times when I help guys out at the field the ATV for both channels are set to the same value which means the ailerons are not moving the same. Then they rarely use the differential feature. This means that when aileron is applied the airplane will not only roll but it will pitch and yaw at the same time. Add in some wind which will require more corrective inputs that are not pure inputs and the airplane is all over the place. The key here is better setup not more weight.
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Old Today, 09:55 AM
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Not agreeing doesn't make you the authority its only your opinion and you know what they say about opinions!!!!!!!!!!!!!!!!!!!!!!!!! Read the ops posts carefully and slowly if you have to. He is interested in competing in scale that means scale like flight as observed from the judges area. Sometimes the wind you are required to fly in is not scale like. Most likely the judges are wanting to see power off flight in something like a fly by, ascending or descending circle which have to be done front and center of the judges with equal and even parts before and after the judges. With a lightly loaded glider type air frame and low penetration this would not be possible without some ballast. This has nothing to do with performance and everything to do with visible representation of scale flight for the judges.

Second of all when talking performance water ballast is often used in full size sailplanes to fine tune the performance. Look up slope and dynamic soaring without ballast the performance they are achieving would not be possible and the amount is adjusted to suit the conditions.

Your statement of a lighter plane always fly's better doesn't ring true in all cases as you would lead us to believe. I have even seen guys flying the 40% in freestyle add ballast to move the CofG back a little further to increase the instability that allows some of the wilder aerobatics when they fly their freestyle routine.

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