by pushinoldrc » Mon Oct 11, 2010 1:23 pm
Since biplanes have different types of wing mounts, it is important that the incidence on each wing, and the stabilizer is checked every so often. I usually check the wing incidences every month, or every 4 to 5 flights. If the incidence of either wing is more than +2 degrees,the airplane will balloon under power. If the tail (horizontal stabilizer) is more than -2 degrees, then the same thing will happen.
I usually set my incidence at 0 for the bottom wing, and +1 to +2 degrees on the top wing with the tail at 0 to -1 degrees on biplanes with ailerons only on the bottom wing.
This allows for a bit of washout for landing. The top wing will stall slightly before the bottom wing, allowing the airplane to settle on landing.
If I am setting up for a biplane with ailerons on both wings, I try to mix slightly less throw on the top wing with the same incidence settings so that I still have some control when it begins to stall.
Usually smaller bipes have greater incidence settings than I prefer, I guess to make them self correcting. I generally try for 0,0,0 if I am trying out a new design to see how it should handle at stall speed.
A few fellows at the field I fly at have gotten bipes, and not been able to fly them because they are used to flying at full throttle for the duration. Most bipes do much better at slow speeds, and perform ALL aerobatic maneuvers quite well.
Besides, a 15 MPH knife edge looks really good.
Bryan
Landing is one aerobatic maneuver that MUST be perfected!