Holystone

Hi Mark

BJ asked me to say thank to you about good report about the Passion.
BJ Park wants give you some tips about how to properly set up the KE and down line pull.
He said, just giving more positive incidence of main lower wing with roughly 2mm spacer,it can kill the pull tendency at KE. and might be mitigate at the down line depend on your power source. .

The background is, this plane has higher HTVC(horizontal tail volume coefficient) and full flying stab. So when the gravity direction is changed like KE or downline, the pull tendency comes out much more from the full flying stab, less from the main wing incidence. So, in order to kill the pull tendency correctly you have to get more main wing incidence.
.
So, Long story short.
(1) Gaining more positive main lower wing incidence, lead the plane left up at level flight.
(2) the full flying stab trim should move to the positive incidence to make the straight flight.
(3) Gained positive incidence of the stab will reduce the pull tendency at KE and down line both. Adjust the incidence with adding up or losing it until get the straight flight without program mixing.

But, please be careful, this correction makes sense only for Passion which has higher HTVC and full flying stab. For other planes may not be correct. So this guide can not be generalized for all F3A pattern flying models. BJ always advise me that there must be consideration of the conditions on that plane first, before we talk about any conclusion…… in order words, before we choose one action for correction, we must consider the planes basic specification and condition. Otherwise it leads the wrong result.
The above correction is the best example……

In your maiden flight with your current CG, the above guidance is verified under the condition of increased main win incidence, strong HTVC which can surpass the main wing twist moment, Full flying stab., long nose moment. Good luck thanks.

Sungho