electron 0 Report post Posted June 22, 2004 some one know if the added surface area of a bi-plane is truely supportive of the extra wing loading i want to support payload and i want light wing loading is a bi plane the logical answer? thanks sky cam electron Quote Share this post Link to post Share on other sites
Mr.RC-Cam 123 Report post Posted June 22, 2004 Some good dialog here: http://www.rcgroups.com/forums/showthread.php?t=202035 Quote Share this post Link to post Share on other sites
Terry 5 Report post Posted June 22, 2004 YES, it maybe the answer you are looking for. I have used a biplane in very tight places where slow speed and tight turning was needed above ultimate duration. I think from memory that 2 wings when used as a biplane equal about 1.5 wings and you need to mount them not closer than 2 cord lengths apart if you can help it. Thats the basics but it can get very involved if you like to argue the t***! Let us know how you get on. Terry UK Quote Share this post Link to post Share on other sites
mikep 0 Report post Posted June 22, 2004 (edited) From my experience, bi-planes tend to have a lot of drag. Ever have to bring one in with a dead stick? They sink like rocks! Personally I don't think they would make a good plane for any payload. A trainer is a much better bet. I've put 4 pounds in my 40 size trainer. Admittedly it also became a sinker... but it still flew quite well. Also the flat bottom and dyhedral in the wing give it some nice qualities for autopilots and RPV'ing. I've also use a Modeltech Cessna 182 model... I fly it with 10% flaps with a heavy load in it and it does quite well. My main "Carrying" machine is a Senior Telemater. It can handle a lot of weight, but considering it's a kit (not ARF) and the flight charateristics are only so so, I don't think I would bother with one again. I would simply look for a 60 size trainer ARF. Edited June 22, 2004 by mikep Quote Share this post Link to post Share on other sites
Robert 0 Report post Posted June 22, 2004 Mikep, I'm kind of a bipe nut. It has been my experience that Bipes tend to carry alot of parasite drag which makes the excellent candidates for radical aerobatics -- downline braking is incredible. Thus the tendency to fall out of the air like a brick. There are a few things you can do to improve the parasite drag situation though. First, try to build it out without flying wires. The flying wires tend to create turbulence in the decalage area and reduce the lift of the upper wing. Also, a slight amount of negative incedence on the upper wing (about 1-2 degrees) also causes the pressure between the upper and lower wing to be reduced making the wing area more effective. Finally, if you must use a bipe choose a model with a stagger configuration. Some candidates that I have found to be have these characteristics include the Waco, Great Lakes, and Hog. Stay away from the Ultimate, Pitts, Weeks, and Stearman if you want payload. If you are looking for a good ARF trainer that does a great job of carrying payload. Try the Frontier Senior ARF. It is built very light and and a .91 OS or Saito 100 will pull this thing all over the sky. I have used one as a paintball carpet bomber. You can pretty much fill up the fuselage with paintballs and the thing just keeps flying. Robert Quote Share this post Link to post Share on other sites
randall1959 0 Report post Posted October 31, 2004 Put a bigger tail on that telemaster and it will fly much better. I used to have one of the big ones and that's what I did and I flew the wings off it till it went deadstick into that powerline.......... Quote Share this post Link to post Share on other sites
Exporter 0 Report post Posted August 3, 2005 Aspect Ratio ( the w.s. divided by the chord) is very important in calculating lift. If we had to wings that would fit on the one airplane.....and say the area was 1000 sq in in both wings but one wing had a chord of 10 in and a w.s. of 100 in while the other wing had a chord of 15 in. and a w.s. of 66.6 in which would give you more lift? I use the absurb to make a point. The 100" span with chord of 10 " would give much more lift than the 66.6 in span and a chord of 15 in. Of course Reynold's Numbers do factor in. That means air speed, etc. So if both of those wings flew at thew same speed ( say 40 MPH) the one with the higher Aspect Ratio will lift more. The 100" wing had an A.R. of 10 and the 66.6 " wing had an A.R. of 4.4! Just a little thought. The A.R. of a piper J-3 is about 7 to 1 or 7. Quote Share this post Link to post Share on other sites
Exporter 0 Report post Posted August 8, 2005 BIPLANE DESIGN. From Model Airplane News. How to design biplanes, some theory. <http://www.findarticles.com/p/articles/mi_qa3819/is_199802/ai_n8799373#continue> A very good article ! Quote Share this post Link to post Share on other sites
