Front wheel pant

[FlyingMonkey]

Dennis, maybe ask FD about an MRA to fly with no front pant, given you’ve already flight tested it with no pant and you might not want to hack up a pant?  I doubt there is any real speed benefit to the nose pant, so if it were me I’d press FD to let me fly without it since it’s their design/manufacturing issue.

[Dennis Yeo]

Appreciate your feedback.  I like the looks of wheel pants.  Airtime said they have a whole stack of bad wheel pants they replaced.  I figured had nothing to lose cutting mine as I can always buy the LS version.   You are in Oregon?

[Runtoeat]

Dennis.  You should end up having a lot of information on this subject after you finish the modification of your wheel pant.   If possible, providing the details of your modification would be good information for those who have a yaw problem caused by the pant.  Is the problem basically that the "bad" pant has more pant surface than the "good" in front of the wheel?

[flyingsparrow]

I red the description of the fairing problem

I am new with the CTSW (2007 equipped with a tundra front wheel). I have the same instability problem and noticed the same jaw problem.

The explanation is that the front wheel fairing I installed behaved like a so called slender body.

It means that when placed a flow with some incidence, the aerodynamics forces create a torque which tends to increase the incidence, 

resulting in an instable behaviour. At low speed the centering spring will maintain the rudder centered.

With a bigger fairing the spring is not strong enough.

If you remove the fairing, The slender body effect do not appear.

Fight design response to the problem is to increase the centering force spring which makes the rudder uncomfortable

Another way is to add at the rear end of the fairing a short wing like a "fish tail"

In this case the "fish tail" effect wiill overcome the instable behaviour.

 

 

[Roger Lee]

The rudder which is affected by your wind forces on the wheel pant has a torque value in the maint. manual. This rudder torque also is the torque for the front wheel. If the springs are too lose then the wind can affect the front wheel / rudder more easily. I have seen a number of the rudder / front wheel spring tension lose. I agree with FD to just tighten the two turn buckles that tension the spring to a higher torque / side to side pressure. They are located just behind the bottom center panel. Since you aren't trying to bias the tension in any one direction then turn each one equally a few turns. Use the method in the manual to see what begining and ending pressure is to see if you did a decent job.

[Anticept]

I am not sure of the CTSW design, but on the CTLS, I was told that proper tension should allow you to pinch the two cables no more than halfway together in the center tunnel with moderate hand force. There's no good place to put an actual tensiometer on these airplanes, so that's the best that can be done.

New cables do stretch a little with age. The cables are twisted, and while they're designed the best they can to stay tightly wound, it happens as they break in. It is something people should be checking for once in a while. Usually after the first tightening though, they don't loosen again anytime soon without wearing down.

It doesn't take much for a cable to get noticibly loose though, when that happens, take a quick look at any fairleads, pulleys, eyelets and swages for wear. Flight Design doesn't have a spec in the manual, but they do say use 43.13 best practices for inspections, and 25% is the wear limit on cables.

[FlyingMonkey]

On 11/24/2019 at 8:43 PM, Dennis Yeo said:

I have been saying mass. But I like surface better!   The old one is getting reglassed as we speak.   Appreciate all the input. 

What are the exact modifications, and where is material removed (or added) from the pant to correct the problem?  Any before/after pictures would be super helpful.

Thanks!

[Roger Lee]

The tension measurement and how to do it is on the rudder and in the maint. manual.

[cdarza]

On 12/22/2021 at 11:54 PM, FlyingMonkey said:

What are the exact modifications, and where is material removed (or added) from the pant to correct the problem?  Any before/after pictures would be super helpful.

Thanks!

Has there been any response to this ?   Ive been flying pants off and its been great without the yaw problem -  but i would still like to get the pants back on as CTSW does look better with them on.