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Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 1:56 pm
by Ultrapilot1
Can we get a mechanical drawing?

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 5:42 pm
by Rich
I've long thought something like this would be worthwhile. Have either of you taken the plane to redline with the adapter mounted?

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 7:10 pm
by Pilot55
At 9000 my plane TAS 148 @ 2450, 5000 TAS 155-156 @ 2550

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 8:23 pm
by Rich
I need to point out that Vne for the DA40 is 178 knots INDICATED airspeed. Since Vne is typically set for 90% of the max tested dive speed and flutter is really generated by TAS I suspect that airplane was tested at the max demonstrated operating altitude of 16,400 ft. This would required a calibrated airspeed of about 192 knots and a TAS of something like 240 knots.

The effects of a flutter induced in this piece is not obvious, but I could foresee a potential situation where if it did happen, the vibrations could feed back through the airframe and induce harmful feedback elsewhere. Better if it just broke off cleanly.

I'm not suggesting you need to go through all the original hoops, but you should at least run it well up into the yellow at a reasonable altitude (8,000 ft?) to see how it holds up. I know I've occasionally had occasion to do a "slam dunk" descent up around 160 KIAS.

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 11:30 pm
by Pilot55
highest decent speed @ 6000 ft I have demonstrated with the fin attached is 165 kts in smooth air. I have had no wheel shimmy on touch down either. The fin is attached by two screws that hold the wheel fairing together. If extreme side loading was imparted on the fin it would brake the composite mount at the screws.

Re: Corked Nose Wheel

Posted: Fri Nov 16, 2018 3:52 am
by Roxi5m9
Just finished my annual, and during it found that the tension on the nose gear was almost nonexistent. So once it was tensioned, I was excited at the thought it would fix the corking. Instead, it corked solid to the right in takeoff loading up a ton of yaw. Time for a fin. Nice job on the aero engineering by the way, Diamond. Not.

Re: Corked Nose Wheel

Posted: Thu Mar 21, 2019 11:27 pm
by Roxi5m9
Is anyone in phone contact with Bret (Pilot55) regarding this nosewheel fin? He messaged about 3 months ago saying it was almost done and haven’t heard since. Tried PMing.

Re: Corked Nose Wheel

Posted: Fri Mar 22, 2019 11:08 am
by OliverBucher
Hello,
is it possible to get a CAD drawing or paper drawing of the fin?
I will also try it with this fin.
Greetings Oliver

Re: Corked Nose Wheel

Posted: Sat Mar 23, 2019 10:48 am
by Pilot55
I have finished the molds for the fin. I am not trying to make any money off of this, I have just found thru testing that this is a simple cheap fix for the nose wheel staying true during flight. You can take this on and off in minutes to test for yourself. The one thing you must remember is to straighten your trim tab on the rudder ounce you install the fin.

Re: Corked Nose Wheel

Posted: Sat Mar 23, 2019 2:53 pm
by CFIDave
Pilot55 wrote: Sat Mar 23, 2019 10:48 amThe one thing you must remember is to straighten your trim tab on the rudder ounce you install the fin.
While you may have found bending the rudder trim tab to be necessary on your particular aircraft, pilots/owners should not assume this to be the case on other DA40s.

When new DA40s leave the factory, they have been flown by Diamond test pilots to make sure that controls and trim tabs have been rigged properly (e.g., the plane doesn't fly one wing low, or with the ball off-center). Experience has shown that many DA40s may have "corked" nose wheels to the left or right -- or may be properly centered -- on a given flight depending on the conditions in which the plane rotated off the runway (e.g., whether crosswind correction was required, or how much pitch up was utilized). I've flown DA40s that fly with the ball perfectly centered on one cross-country leg, but then may have a corked nose wheel on the next leg. On some planes it seems to be random chance whether you will encounter a corked nose wheel on a given flight; on others the nose wheel seems to always be corked.

Bottom line: Don't adjust your rudder (or wing) trim tab unless absolutely necessary, since you could make the trim of your aircraft worse.