Repairing flaperons

[Dorsal]

Yes you need to disconnect the linkage to the flapperon control horn to fold the wing.

[chefwarthog]

Merci Dorsal!!

I was thinking on the older model like the KF 2,3,4,5 we have to disconect the flaperons, it's not a big deal to disconect them anyway!!!
thanks for the info!!!

[jrevens]

Those are all good points, Fred. The fact that it has been done by others, and also proven to be OK by you for so many years up to now is a good testimonial to the change probably being safe. The flying and testing is the only way to know for sure. I tend to be, perhaps, over cautious about changes to a design like that, having been privy to an ugly lawsuit where a relatively minor change was made to a homebuilt involved in a fatal crash, and the lawyer(s) jumped all over it even though it had nothing to do with the accident. Flutter is also a complicated issue. It's amazing how a tiny, relatively minor change can make a surface more vulnerable. It's sometimes impossible to predict what will happen if, for instance, someone were to inadvertently dive the aircraft beyond the red line speed and "excite" the surface with a sudden movement of the controls. You might be surprised to see the very simple and tiny change that made the most difference in preventing a flutter issue with the Thorp T-18 stabilator. A very small amount of additional stiffness was created where the anti-servo tab end rib is connected to its hinge by adding a thin (.015") strip of stainless steel between the rib and the hinge. It was stated in print by the designer, after extensive instrumented testing, that the assembly was most probably flutter-proof up to the speed of sound after that. Stiffness between interconnected components can be a huge factor for flutter, and tiny changes can make a world of difference. This is all just an interesting conversation/subject to me, and I don't want you to think that I was trying to make you worry unnecessarily about what you did.

[Maverick]

I can understand your reservation and one should follow their own mind about about it. And, this is pertaining to a series 5. I don't know about the later series or the 1-4.

I did this on my first Kitfox and it's still flying 18 years later. As well, I know of others in the Phoenix area that have also done this. So far, none off them have fallen out of the sky. As for the location as advised by the factory, I don't know how they came to that decision. Mabey it was aesthetics. I am not concerned about flutter because the flaperons are well balanced with the two weights on both flaperons and the balance wouldn't change based on the location of the weights on the flying surface, inboard or out board. Many designers add the weights at either the outboard end of the flying surface or inboard at the beginning of the surface. In the case of the Kitfox, it's sort of both. As long as the offsetting weight of the attachment is ahead of the pivot point of the flying surface and there is static balance, flutter is highly unlikely in an airplane that flies the speeds of a Kitfox. The strength of the attachment of the weights isn't going to be affected much by the location because of how they are designed. I can see that it wouldn't be wise to put the two weights close together, i.e. side by side but them being far apart, the stress of the weights would well dispersed.

It's just a suggestion. I've yet to have the problem of the hinges cutting/denting the aluminum.
Fred