Wing Flex Question

[Helicopter D]

After a full summer of covering and painting I got my wings installed today. I used the prefabed Douglas Fir spars from Wag aero, now I've never flown a Taylorcraft or been around too many wood spar wings and still haven't hooked up the jury struts but to me they just seem to have a lot of flex in these wings. Is this normal for a Taylorcraft?

[Guest]

Re: Wing Flex Question

Hi Dustin,

Without some specifics I can't answer the question.

What specifically are you noticing?

Flex in what axis?

What are you doing to the wing to observe the flex?

I am afraid to say sure that's no problem then discover that something is really wrong.

Can you elaborate?

Dave

[astjp2]

Re: Wing Flex Question

in short, yes they flex a lot if you grab the tip and shake it up and down, mine will move probably a few inches. tim

[magman]

Re: Wing Flex Question

Sounds like low Drag Wire Tension to me.

Flew a Tripacer that had "Wing Shake" & that was the cause.

Really didn't like a wing shaking around !!!

[Scott]

Re: Wing Flex Question

Drag wires have no effect on vertical wing flex (which I gather is what Dustin is referring to). As the name suggests "Drag" and anti-drag wires give the wing rigidity for and aft. The spars, struts, jury struts and to some extent the leading edges comprise the structure providing rigidity vertically.

I have no experience with fir, but I think you'll be a little more comfortable once the jury struts are installed and rigged. If you're more familiar with built-up aluminium structure, you won't see that kind of rigidity in a wood spar wing. Note that rigidity, or lack thereof, is not necessarily an indication of strength.

[PA1195]

Re: Wing Flex Question

I've had four planes with wood spars...two T's and a couple of Citabrias. They can all flap their wings like ducks unlike metal spars, especially in rough water on floats. One of my Citabrias had Madras droop tips. In turbulence they'd move around more than stock wings.

Jumping between Supercubs and my Citabrias I could feel the difference. The Cubs are solid and hard riding in the wind, the wood wings give a little.

The only caution would be aileron reversal in an extra loose wing due to flexing, but at the speeds and loads the Taylorcraft lives at some flexing of the spars shouldn't be a problem.

Gary

[Helicopter D]

Re: Wing Flex Question

Just want to say thanks for the responses. I had an old timer and fabric guru trammel and set the drag wire tensions so I'm guessing I'm just not use to wood spars and got ahead of myself and maybe a little panicked. I tried to compare with a Champ but it's on spring gear and it just kind of wobbles when you move the wing. Thanks again!

[3Dreaming]

Re: Wing Flex Question

A Champ on spring gear instead of oleos could have metal spars, and they would be stiffer.