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Wing Rigging

Snappy

Well-Known Member
Supporting Member
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Jul 31, 2020
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Washington
After flying my 29 year old, New to Me Hatz for a hundred hours, I thought I'd check the wing and tail rigging against plans. The main reason was because three point landings were difficult to do without bouncing or dropping it in, even though the plane flew pretty straight after I added a (tapped on wood wedge for now) rudder trim tab.
After carefully leveling the fuselage, the incidence was:
Bottom wings were at +.9 degrees at the root
Bottom left was +1.4 degrees at the N Strut.
Bottom Right was +1.4 degrees
Center section was +1.4
Top left was +1 !!
Top right was -1.5
Dihedral was 2 degrees on both, GOOD!
The horizontal and vertical stabilizers were close so we adjusted to plans.

Sooooo, we set everything at "0" as specified, tuned the wires and adjusted. The top wing is straight with "0" incidence and dihedral.
The bottom ailerons were in line but the tops were WAY out. The left was 4 degrees down and the right was 7 degrees up! I centered the stick and clamped the lower aileron trailing edges to the wings, then matched the top aileron trailing edges also to the wing, tuned the wires and rechecked. All good!
In flight, the bottom aileron trailing edges matched the wings but the tops were off and it had a minor left roll. I adjusted the tops again to match the inflight (approximate) wing trailing edges and flew. Still heavy left so back to the hangar and found the incidence at the N struts had changed slightly. Again, reset to "0" and tuned the wires.
After flying yesterday, I still have a slight left roll. The incidence is exact and on the ground, the ailerons are in line. BUT, in flight the aileron trailing edges are not.
Question: Do I add/decrease incidence at the N struts to balance the roll and keep tweaking the ailerons? Should I reset the ailerons? The rudder trim is good at cruise and there is no fin offset. By the way, all inflight checks were done at 1500msl, 2000rpm 95mph. Note: The speed increased from 90 to 95 after initial rigging :)
Regarding the hard to 3point, now the flair is gradual. Before, it just quit flying and dropped in. Both wheelies and 3pointers are easier.
Any help here would be GREATLY appreciated!
 

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