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Corked Nose Wheel

Posted: Fri Sep 28, 2018 7:39 pm
by Pilot55
Here is a simple solution to the corked nose wheel. It is fiberglass and bolts in place in minutes. It can be removed at any time. The planes fly's straight and true.

Re: Corked Nose Wheel

Posted: Fri Sep 28, 2018 9:03 pm
by smoss
Did you make that yourself? Random shape, or is there some wisdom behind the design?

Re: Corked Nose Wheel

Posted: Fri Sep 28, 2018 9:38 pm
by Pilot55
It was designed with CFD software. I am a engineer that specializes in fluid dynamics

Re: Corked Nose Wheel

Posted: Fri Sep 28, 2018 9:53 pm
by Don
Pilot55 wrote:Here is a simple solution to the corked nose wheel. It is fiberglass and bolts in place in minutes. It can be removed at any time. The planes fly's straight and true.
Great idea. That said, is it FAA legal?

Re: Corked Nose Wheel

Posted: Fri Sep 28, 2018 9:58 pm
by smoss
I'll take one! When are you going to start cranking them out for us???

Re: Corked Nose Wheel

Posted: Fri Sep 28, 2018 11:49 pm
by Antoine
I am going to sue you for this! This solution was invented in Zimbabwe and ZAA approved some time ago.
Why not take advantage of the graceful shape allowed by composites ? (ah and I don't buy your "CFD Software" story, sorry)
Capture d’écran 2018-09-29 à 01.43.45.png
More seriously:

1. yes it works and the shape and size above is exactly what was needed to make that specific plane (a 2007 XL) fly level and perfectly coordinated with no trim tab on the rudder ( I did go through 2 iterations, first one was too big). Speed gain approximately is 4 to 5 knots versus flying with the nose wheel pointing sideways and teh trim tab working against it - as many DA40s came from the factory.
2. from my recent learning about FAA-approval of field modifications I believe a motivated A&P IA can pull this through as a Form 337 Major Modification.
And once ONE plane is modified and approved, this is as good as an STC.

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 10:28 am
by Pilot55
So you want to sue me? total different design. A simple laser scan of the wheel pant 3d and modeled in solidworks and ran through cfd. I do not care if you think it was produced that way or not. My design is a simple bolt on solution instead of a complete composite wheel pant design. Your pic with the fiberglass fin is a great design.

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 10:39 am
by ThomasD
Hello Bret,

I am sure Antoine was joking..

Anyway, there are a lot of us on here who would be interested in your solution, particularly buying it if a 337 has been done. (Perhaps unrealistic, but I would have thought that even the factory really should be interested, considering how well-known this problem is.)

Tom

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 12:14 pm
by Antoine
Of course I am joking Bret!
Do whatever you want!
I just found it funny that you came up with this design which I had also tested a couple years ago.

Meaningful CFD simulation of this would require accurate modeling of the prop wash and interference of the strut. Did you really do that?

FWIW mine was a fiberglass "hat" fitted from behind. I re-used two of the existing screws for attachment.
The fin itself was a relatively thick (about 1/3 inch) airfoil with a wooden core.
If an A&P does this mod under Form 337 I would recommend they extend one (or both) of the wheel pant halves and make the fin permanent.

I said this a few times before but here again in case it got lost: if you suspect that your nose wheel is not flying straight, then remove the fairing and observe the change in TAS.
If speed increases (1 knot) without the fairing, the nose wheel problem exists. If speed decreases (3-4 knots) you are fine.

Re: Corked Nose Wheel

Posted: Sat Sep 29, 2018 1:34 pm
by Pilot55
I measured the velocity of the air flow from the center line of the prop at different locations from the underside of the plane. I then offset the front wheel strut and fairing in relation to the center line. I constructed the fine from honeycomb core. it has very little mass. the simple test is to fly the aircraft. set the ruder trim tab to neutral. The plane should fly true. My da40 did the first time out and continues to fly true.