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Design => Engineering board => Topic started by: Michael Boucher on October 18, 2011, 07:10:48 AM

Title: Incident set up on a Bipeplane
Post by: Michael Boucher on October 18, 2011, 07:10:48 AM
Hi, How would you set up the incident on a profile biplane? Zero degree on the lower wing, two to three degree on the top wing or zero as well?  The plane also has dihedral.   ???   Thanks, Mike
Title: Re: Incident set up on a Bipeplane
Post by: PerttiMe on October 18, 2011, 07:18:22 AM
Is this biplane for aerobatics or scale-like flying "right side up"?
Title: Re: Incident set up on a Bipeplane
Post by: Michael Boucher on October 18, 2011, 07:59:00 AM
It's for right side up flying but would like to know how to set up for both types of flying, thanks.  Mike  H^^
Title: Re: Incident set up on a Bipeplane
Post by: PerttiMe on October 18, 2011, 09:00:46 AM
John Miller built an aerobatic bipe a while ago:

http://stunthanger.com/smf/index.php?topic=21572.50
http://stunthanger.com/smf/index.php?topic=19379.0
http://stunthanger.com/smf/index.php?topic=22597.0

Equal incidences seem to work there. I'm pretty sure it would work for non-aerobatic flying too. I believe some "full size" biplanes use more incidence on the more forward wing for softer stall behavior.
Title: Re: Incident set up on a Bipeplane
Post by: Michael Boucher on October 18, 2011, 10:00:04 AM
Thank you PerttiMe  H^^
Title: Re: Incident set up on a Bipeplane
Post by: WhittleN on October 19, 2011, 10:52:43 AM
Michael/John
It is customary to add a little positive incidence in the bottom wing to make up for the interference drag. You may note the top wing flies in clean air and the one sticking out of that Fuselage thing doesn’t.   Another solution might be to go about ½ deg negative on the top wing to balance the lift.
Norm
Title: Re: Incident set up on a Bipeplane
Post by: Don Hutchinson AMA5402 on October 19, 2011, 06:30:11 PM
The Stearman models I built all were set up with zero incidence on both wings. They fly just fine that way and will turn a very credible pattern in the hands of a skilled pilot.