SKYWARRIOR 0 Posted May 10, 2010 Share Posted May 10, 2010 Hi, I am new to gliding and the Discus is great however i am using FSUIPC to operate the elevator trim. I get the full range but always seem to be at 18-20 down trim. I have tried re centering the FSUIPC settings and have dumped all the water. The water ballast has a slight nose down effect when dumping but it still all settles with down trim being required. How do i set up these aircraft to be neutral trim. Is there an aircraft set menu which I have not discovered yet. My friend who is a gliding instructor is going to come and advise me on the ways of the C4 unit and I suppose will offer trim advice as well but since he does not know the program I need to know how to adjust settings like ballast and passenger weight etc. Any help welcome Thank you David Link to comment Share on other sites More sharing options...
James A 39 Posted May 10, 2010 Share Posted May 10, 2010 Hi David, I use FSUIPC4's option to use mouse wheel for trim and have no issues. Do you use the same option? Link to comment Share on other sites More sharing options...
SKYWARRIOR 0 Posted May 10, 2010 Author Share Posted May 10, 2010 Hi, I have assigned a throttle quadrant lever to the elevator trim using FSUIPC which works very well. It has a large movement and in principal works fine. Its the center which is always not in the center. ie I need to balance the aircrafts C.G. better and I have tried this by dumping water ballast which makes a difference in the right direction but not enough. I am always almost flying with appx -17 of trim and feel the need to get this in level flight more around the zero. When I am flying my model jets I would physically add/reduce weight to get the trim around the center. I have also tried adjusting the center of trim in the FSUIPC axis calibration panel but too the same effect. It flies but I cant believe it right as it is given the superb finesse of this aircraft. regards David PS Or where can I add some weight in the nose ? Link to comment Share on other sites More sharing options...
J.Schweigler 203 Posted May 11, 2010 Share Posted May 11, 2010 The trim position has nothing to do with the CG. The Plane is wenn balanced. It is normal, that you might get a not centered trim tab in normal flight. This is what the trim is for. You will feel it in every full scale plane. Bests Joachim Link to comment Share on other sites More sharing options...
SKYWARRIOR 0 Posted May 11, 2010 Author Share Posted May 11, 2010 Joachim, Thank you for your reply and comments. What I therefore dont understand is what the water ballast is for if not to alter or maintain a desired CG ? In the model plane I fly we add and reduce weight before and after the CG to change its position and to achieve level trimmed flight. How does this alter on a glider? Perhaps you could advise me of a simple instruction book or doc on flying the Discus which would help me understand this a little better. In any event thank you once again and i enclose a couple of models that I currently fly in the manner described. Regards David Link to comment Share on other sites More sharing options...
J.Schweigler 203 Posted May 11, 2010 Share Posted May 11, 2010 The water ballast system on the discus and in every other glider is tio increase the take of weight, not to reposotion the CG. This CAN be don with the rear ballast tank if you're very heavy. Normally the rear tank is to ballance the plane when using the normal ballast tanks in the wings wich are slightly in front of the normal CG so if not filling it the plane would become nose heavy. The porpose to get the plane more heavy is to get it faster without loosing performance. You can slide the gliding polar to the faster end. But you'll get a higher minimum sink rate. So be carefull in weak weather conditions. Cheers Joachim Link to comment Share on other sites More sharing options...
B21 19 Posted May 12, 2010 Share Posted May 12, 2010 In strong conditions, heavier = faster. But if things get weaker you might want to lose a bit of weight so you can climb better in the weak lift - that's why you carry water instead of simply lining the fuselage with lead weights - you can legally dump it. In fact only three things can be legally dumped from an aircraft in normal flight - water, sand, and people. In the two-seater open class world championships it is common for the second pilot to parachute out of the glider if conditions turn weak (ok I lied about that bit). Water ballast: http://en.wikipedia.org/wiki/Gliding_competitions#Water_ballast Also the Open University videos on soaring talk about it a bit, e.g. see the last video in the series (The Art of Soaring) and the pilot talks about dropping ballast about half way through the video. B21 Link to comment Share on other sites More sharing options...
SKYWARRIOR 0 Posted May 12, 2010 Author Share Posted May 12, 2010 In strong conditions, heavier = faster. But if things get weaker you might want to lose a bit of weight so you can climb better in the weak lift - that's why you carry water instead of simply lining the fuselage with lead weights - you can legally dump it. In fact only three things can be legally dumped from an aircraft in normal flight - water, sand, and people. In the two-seater open class world championships it is common for the second pilot to parachute out of the glider if conditions turn weak (ok I lied about that bit). Water ballast: http://en.wikipedia.org/wiki/Gliding_competitions#Water_ballast Also the Open University videos on soaring talk about it a bit, e.g. see the last video in the series (The Art of Soaring) and the pilot talks about dropping ballast about half way through the video. B21 Thank you both for your help and interest David Link to comment Share on other sites More sharing options...
SKYWARRIOR 0 Posted May 13, 2010 Author Share Posted May 13, 2010 Thank you both for your help and interest David Thank you for the video link Learnt a lot and wondered if you can suggest any more like it. For instance beginners guide to the C4 computer would b good. Although I have downloaded the handbook and i believe its calibrate for the Discus as given I am unsure how to put it into practice and a beginners guide would be ideal. Also any further video info all consumed with the same ineterest. Thanks again David Also before I appear a complete idiot there are 4 topics started by me in this forum which are a mistake due to my inability to upload pics on four occasions and it seems to have created four topics. I would like to have them removed and am trying to contact the webmaster. Any ideas ? Link to comment Share on other sites More sharing options...
James A 39 Posted May 14, 2010 Share Posted May 14, 2010 Also before I appear a complete idiot there are 4 topics started by me in this forum which are a mistake due to my inability to upload pics on four occasions and it seems to have created four topics. I would like to have them removed and am trying to contact the webmaster. Any ideas ? Hi David, At the bottom of your post you should have the option button to delete the post! Link to comment Share on other sites More sharing options...
J.Schweigler 203 Posted May 14, 2010 Share Posted May 14, 2010 It you want to delete an entire topic, a moderator must do this. Ask Thorsten Reichard via PM. As far as I know, there is no beginners manual for the C4. Only the original one. But why have you downloaded it? It is part of the pakage as well as original manuals for the planes in Englisch and German. Bests Joachim Link to comment Share on other sites More sharing options...
SKYWARRIOR 0 Posted May 14, 2010 Author Share Posted May 14, 2010 It you want to delete an entire topic, a moderator must do this. Ask Thorsten Reichard via PM. As far as I know, there is no beginners manual for the C4. Only the original one. But why have you downloaded it? It is part of the pakage as well as original manuals for the planes in Englisch and German. Bests Joachim Hi, I should have not said download but printed off the included package as you suggested. Thank you for your help Regards David Link to comment Share on other sites More sharing options...
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