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AVanlent
05-18-2014, 04:29 PM
Hey guys! I have a Kitfox 2. Little did i know, i can't take a passenger any heavier than 130 pounds if I'm full of fuel. My gross weight is 950 pounds. What needs to be done to up the gross weight? I have heard its in the wings. Do Kitfox 4 wings fit on the model 2?
Also, what can be done to make the rudder and stabilizer bigger? Is there a kit for it?
Thanks for the input!
Andy

rogerh12
05-20-2014, 09:25 PM
Gross weight has to do with the rated max G-load on the wings, but also the landing gear capacity, engine size ect.... It's not just one thing. Clipping the wings on a model-4-1200 will allow a high G-load on the air frame ( mathematically speaking), and that is what I am doing to raise the gross weight to 1250 lbs on mine, but I also installed upgraded aluminum landing gear and a more powerful engine to take the extra load up in the air, and put it safely back on the ground again.

So what's the limiting factor on your model 2? Probably Engine HP for a decent rate of climb, as I doubt you are going to break the wings or landing gear (though I have heard of breaking off the bungee attachment on a hard landing, collapsing the gear). Anyway, if you modify the plane for a high gross weight, you have to run it past the FAA, and they will probably issue you a new pick slip with the increase rating listed, along with some test hours (5 or 10), but their response seems to vary with the particular office you go though (my local office does not seem to care about prop-planes, as they are in Wichita, home of the big planes).

Hope this helps
Roger

cap01
05-20-2014, 11:09 PM
roger is correct , there is more to it than the wings . the original owner of my model 4 1050 has documented mods that he made to increase the gross to 1200 or 1250 . I've never been able understand who came up with the mods . the wing struts use a larger diameter material . the fuselage carry thru tube for the lower strut attach fittings had been opened up and a solid rod installed in side it and welded back up . the grove gear would eliminate the weak webbing where the bungees attach. these mods done to mine may have been so it could be put on floats as the skag thing that goes below the tail came with the kit . the original owner didn't install the grove gear .
i know the avids used a thicker wall tubing for the spars on the wings but haven't been interested enough to check the thickness on the model 4 1050 and 1200 .

as for the vert fin and rudder , that will have to be done the old fashioned way . that was last winter project for my model 4 . turned into a littler bigger project than i expected . i bought a 4 1200 rudder and made the vert fin taller . at the same time i installed elevator trim .