Biplane Performance
#1
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Biplane Performance
Why do you not see many giant scale biplanes?
I recently completed a World Models Ultimate ARF (54" ws, 10 lbs w/ YS 1.40) and was thinking about getting the Aeroworks 100cc Ultimate. HOWEVER, I have so far not been very impressed with the flying characteristics of a smaller bipe. The CG is a little forward (it lands very fast, moderate amount of down elevator while inverted, drops out of an inverted 45 degree upline fairly quickly), so have been moving the CG back slowly. However, it just does not fly in a stable manner. Just touchy upright, inverted, up, down, etc.... Trying to perform some of the IMAC sequences have also proven frustrating. My Goldberg Extra is much more tame, let alone the 80 and 100 cc single wing planes I have.
Is this typical of a bipe, or do I have some possible alignment issues?
Trev
#2
My Feedback: (158)
RE: Biplane Performance
Ultimate Bpies are notorious for liking speed and power,, as soon as you back off the throttle everything bad is exaggerated. Especially smaller ones with high wing loading. As you go bigger they tend to be a little more gentle.
As far as the lack of BIG Bipes,, they get to be a PITA to put together all the time,, most over 60" span won't fit in a truck or trailer,, that's the #1 complaint I have and that I hear
As far as the lack of BIG Bipes,, they get to be a PITA to put together all the time,, most over 60" span won't fit in a truck or trailer,, that's the #1 complaint I have and that I hear
#3
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RE: Biplane Performance
I think you just got a bad Ultimate...
I love my Great Planes Ultimate Bipe with a DA-50. No bad tendencies and flies like a dream. There is a huge thread on it. The PAU Ultimate has good reviews and the Hanger 9 46% Ulti is/was very popular. My GP Ulti is a little more work than my Yak to put together. No wires to hook up so it isn't bad. I have seen guys with Biplanes that have to be wired up and take almost an hour to assemble. That is not the case with the GP Ultimate. I think the PAU Ulti was redesigned to get rid of the wires - similar to the GP with just struts between the wings.
The CG on the GP Bipe was very forward with the DA in it. I moved the receiver battery all the way back to the tail and even added a little weight to get it slightly tail heavy for 3D. Gotta get your CG right no matter what type of plane you fly.
I love my Great Planes Ultimate Bipe with a DA-50. No bad tendencies and flies like a dream. There is a huge thread on it. The PAU Ultimate has good reviews and the Hanger 9 46% Ulti is/was very popular. My GP Ulti is a little more work than my Yak to put together. No wires to hook up so it isn't bad. I have seen guys with Biplanes that have to be wired up and take almost an hour to assemble. That is not the case with the GP Ultimate. I think the PAU Ulti was redesigned to get rid of the wires - similar to the GP with just struts between the wings.
The CG on the GP Bipe was very forward with the DA in it. I moved the receiver battery all the way back to the tail and even added a little weight to get it slightly tail heavy for 3D. Gotta get your CG right no matter what type of plane you fly.
#4
My Feedback: (21)
RE: Biplane Performance
Something is not right with your setup. Ultimates are usually really tame on low rates (that is if "your" low rates are low enough) and really cut loose with high rates. That is even with a CG that is more to the rear. Thats been my experience anyway. The Ultimate is actually my favorite plane. Haven't flown a Pitts yet, so I can't compare. I have two different versions of the Pitts that are still in their boxes. Maybe one of those will take the honors as the favorite one.
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RE: Biplane Performance
I have a GP Super Stearman and until I corrected the wing incidence it flew terrible and landed even worse. The top wing had +2 wing incidence (should be 0) and it would stall before the bottom wing, you always want the wing that is forward the most to stall last or at least around the same time. Get an incidence meter and find out what all the surfaces should be and check them.
Ya it's a pain to put together but they sure look nice.
Ya it's a pain to put together but they sure look nice.
#6
RE: Biplane Performance
Trev, I have two Ultimates...the CG kit built, and the AW 50cc. Both are pretty docile on landing and in the air. The AW is definitely easier to land, but the CG version has no issues on landing. It needs some throttle, not just idling, to land with enough air under the wings, but it does nothing squirrely at all to me. I think the CofG is relatively more aft on the AW than the Goldberg, but they both fly all the pattern well. I am wondering if the wing loading is just too high on your friends plane, or maybe it has alignment issues like you are guessing. The Ultimate is a good design that should fly well. Wish we could see it to help you out more! Jon
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RE: Biplane Performance
I have a 60" Dave Patrick Ultimate with a OS 1.60 and it is one of the most fun airplane I have ever had. the out side snaps are unbeliveable, and it does a good job on the IMAC basic and sportsman Although I personally am not competive the airplane is more than capable I wound up with a Xoar 17X8 prop and the vertical is unbelivable !!!