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Full Length Rudders


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I've seen some emails floating around on rudders that are cut to the top of the winglet (no fixed portion), and changes to rudder chord. Some personal thoughts that might be relevant:


a. If you cut your rudder to the top of the winglet, you will not be able to see an in-trail position from the cockpit. My rudders were 1/4" to 3/8" out at the tops on the ground due to a rudder cable re-route in the hell hole during the downdraft mod. I assumed aerodynamic loads would provide enough pressure to close them on the first test flight and didn't bother to fix it prior (not much was needed when hand force was applied). Wrong. Glad I have fixed tips.


b. If you move your entire rudder hinge line forward by a fixed amount (I've seen references to 0.5" and 1" to account for no lower winglets or winglet changes), you may not have a straight rudder hinge line and they will bind. Think geometrically. You probably need to stick to the same airfoil chord percentage and account for twist, although it's nice that it's on a relatively flat side of the airfoil for us. Easy way: Use a straight edge, and lie it on edge onto the winglet surface. Check b4 cutting (I knife trimmed out my ailerons and rudders after I did this)...


This is another good reason to ensure you don't have hotwire lag at the aileron or rudder hinge line. I'd do Ronneberg style oversize airfoil tremplates and sand the cores back in a heartbeat - besides, you'll get much nicer and straighter cores and have less micro, less sanding and less time & $$ to outlay to get your machine in the air.


Rudder chord hence hinge line position, and rudder area without lower winglets are all easily planned for and defined concurrently. Don't ruin your day. Rework when building sucks.


good times,



Wayne Blackler

IO-360 Long EZ


Melbourne, AUSTRALIA


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Can't really help you with your question, but I'm sure glad mine don't go to the bottom ... so far my plane has tipped on its tail 3 times!


While building my Cozy, it became apparent from the emails passing thru my computer that this is going to happen, sooner or later, so I reinforced this area ... and am glad i did!



I live in my own little world! but its OK, they know me here!

Chris Van Hoof, Johannesburg, South Africa operate from FASY (Baragwanath)

Cozy Mk IV, ZU-CZZ, IO-360 (200hp) 70x80 prop

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