I recently discovered a drawing created by Vernon Payne the designer of the Knight Twister biplane. It shows the method he used to calculate the aircraft's CG. 25% of the MAC of each wing is inline with 25% of all the ribs. All ribs are alined at 25% chord. (see lower drawing)
He uses 22% for CP. Airfoil is NACA M6.
It appears he used trial and error to get the top two equations to balance as they are not exactly the same.
Is this the proper method for locating the CG on a biplane? Where does he come up with the CG being 3" below the top of the top longeron? Shouldn't the CG be located somewhere along the red 25% line?
Help me understand. Thanks
He uses 22% for CP. Airfoil is NACA M6.
It appears he used trial and error to get the top two equations to balance as they are not exactly the same.
Is this the proper method for locating the CG on a biplane? Where does he come up with the CG being 3" below the top of the top longeron? Shouldn't the CG be located somewhere along the red 25% line?
Help me understand. Thanks
