rebuilding a ultralight biplane.

[james colson]

I am rebuilding a mr. easy bipe. I have a 24 foot (12 feet per wing) wing span on the top wing and 23'8" bottom wing. I also have the frame from an MX and can extend the top wing on the mr. easy using the MX parts. will it be beneficial or detrimental to the flight characteristics, or neither?

[FlyingRon]

Just making the wing longer isn't necessarily going to increase performance. Further, there are all sorts of variables here where doing this might indeed make things worse...anywhere from decreasing the performance (adding drag is the most likely outcome and ULs aren't particularly known for having a lot of excess power) to adversely affecting the controllability if you change the center of lift or cause other aerodynamic changes. Unless you are willing to be a test pilot and have some basic understanding of aerodynamics, it's not advisable to make willy-nilly changes to existing designs.

[james colson]

thanks, that is what I was afraid of. I am going to be the test pilot as it is, and unless it would be a great improvement I don't want to do it.

[martymayes]

I doubt if you will notice any difference. I'd be tempted to go for it just to experiment with decalage. Set it up so in cruise it's flying on the top wing only. That might be fun.

As far as test piloting, this is an ultralight. You're a test pilot every time you fly it.

[crusty old aviator]

Increasing the wingspan also increases the stress on the spar roots and hardware, as well as the attachment points for the wires and interplane struts. You can experiment, but do the math first, with a good safety margin, and at least you'll know she won't fold up on you in a turn, if she can turn...