Composite Leading Edge

[HighWing]

Lowell - Are you getting any oil-canning from the flexing of the wing with this setup?

Larry,
I guess the short answer is - I don't know. When we were thinking of this, I remembered Hal who at the time flew an early Rans S-7. He would often get oil canning while on the ground. When it was pointed out to him, he would grab the wing tip and with a big grin, shake the tip and the wing would pop straight.

I decided I needed it straight on the ground to void people pointing out my crooked wing. When building, I supported the wing at the root end and at the lift strut brackets so it would be in it's typical unloaded ground geometry and hopefully lie straight when people could see it. I riveted a "Z" channel at the trailing edge of the aluminum as a stiffener there and the Z loosely captures the stringer that would normally support the aft ends of the false ribs (I eliminated the false ribs entirely to help compensate for the weight of the aluminum). The one thing I overlooked in my planning was the weight of full tanks while on the ground. On rare occasions, the bay immediately outboard of the right wing tank will show a slight depression near the trailing edge of the aluminum, but not consistently and it is only visible from the vantage point of a ladder.

The "I don't know" part of the answer really refers to what it looks like in the air when it tries to flex and assume other than the at rest geometry. With that in mind, though, it does seem to fly better - but that might be akin to how much better a car feels after washing it. One definite and measurable improvement is full power stalls - much more stable, not the violent wing drop I used to get with my first Model IV. Sorry for the quality of the attached image, but it shows the general appearance while on the ground.