hi guys 

I'm building a CH640 so I don't know much about the high wing members of the family

Is the flap slot open on the fuselage side....on all models?....

 I was curious if something can be done to close up or modify the flap slot...I thought it might get drafty in the winter..I saw a you tube video of a plane that had removed it by making the flap shaft internal to the wing...is that a common modification?

if you guys could educate me on this item...much appreciated...


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A detailed description of the "no slot flaperon" mod can be found here: http://www.liming.org/ch801/FHNSF.html

From my observation over the years as forum moderator, I wouldn't describe it as a "common" mod, but I do believe several members have done this on 801's and 750's.  If I was doing a build now, I'd definitely give it serious consideration.  I'm pretty sure that the fuselage kit's skin could be ordered from Zenith with the slots deleted.

However, the slot is not drafty at all.  On the inside of the fuselage, the slot and the entire flaperon control arm are totally enclosed - you can see the vertical enclosure on the right in this picture:

There is a small access hole near the top of the internal cover so you can access the nut where the control arm connects to the flaperon, but this is typically plugged with a metal or plastic plug.

As I said, if I had it to do over again, I would likely delete the slot.  In my area (East Tennessee), we have a problem with dirt daubers/mud wasps and more than once I've discovered one of their mud nests inside the slot.  I finally made a "plug" for the slot by slotting a sponge on one side and facing it with a felt-like material so I can easily slip it between the inboard flaperon end and the slot to plug it when hangared:

I need to (and will!) flag these with red "REMOVE BEFORE FLIGHT" streamers, but I don't think they exhibit enough wedging force to jam the controls if I forgot to remove them.



Thank you for the detailed explination

much appreciated 


Gary Liming has a very good write up on this mod in the 801,  available at link below......



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