Biplane Wing Incidence

[pbrguy]

I'm building a Balsa USA Phaeton 90 and have read a number of threads on wing incidence, some recommending positive vs. negative, etc. If the intent is to have the upper (forward) wing stall first, shouldn't the leading edge of the upper wing be raised slightly ( 1 to 2 deg)? If so, is this considered positive or negative incidence?

Also, does anyone have any recommended improvements to the cabane/N-strut set-up on this model? Thanx.

[gnats82]

I'm building a Balsa USA Phaeton 90 and have read a number of threads on wing incidence, some recommending positive vs. negative, etc. If the intent is to have the upper (forward) wing stall first, shouldn't the leading edge of the upper wing be raised slightly ( 1 to 2 deg)? If so, is this considered positive or negative incidence?

Also, does anyone have any recommended improvements to the cabane/N-strut set-up on this model? Thanx.

Yes, raising the leading edge of a wing is giving it positive incidence and it will tend to stall first in the case of a biplane.

[Staggerflyer]

In the case of the Phaeton 90, use the incidences shown on the plans. This plane is a fantastic flyer when built as shown. Very stable, yet highly aerobatic, lands at walking speed. We have 3 of them in our club, one is over 15 years old! has worn out three motors, all Saito 4 strokes. First one was a .90, next a 1.20, now has second 1.50 on it! Only one crash, resulting in a rebuild of forward fuse, when firewall let go three years ago.