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  #21  
Old 11-14-2015, 07:52 AM
Captain Avgas Captain Avgas is offline
 
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Location: Melbourne, Australia
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Quote:
Originally Posted by curtis View Post
No airframe is perfect and by moving gear leg fairings, wheel pants, flap positions, wing tips, etc.. to correct the yaw in flight is just hiding the correction that an external trim tab provides. Now if you actually find one of the listed items actually out of the proper position that is one thing, but to just move them around until you don't need a trim tab is just hiding the fact.
No-one is suggesting that the OP just move his gear fairings around randomly to try to centre the ball. The proposal recommended is a more scientific approach.

Firstly the fairings are removed and the aircraft is flown. That's a pretty easy thing to do. If the ball moves to centre that is a clear indication that one or more of the gear fairings are mis-rigged. In that event the solution is to re-rig the gear fairing(s) to put them into correct trail. Problem solved.

I don't think a rudder trim tab is the end of the world but nor do I think it is an elegant or aerodynamically efficient solution to an obvious misrigging problem.
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Last edited by Captain Avgas : 11-14-2015 at 08:02 AM.
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  #22  
Old 11-14-2015, 08:59 AM
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curtis curtis is offline
 
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I agree that flying your aircraft with the fairings removed is easy to do, but that is where the easy portion ends. If you already have drilled the attachment holes for both the wheel pants and gear leg intersection fairings you cannot just reposition them, you have to glass the holes shut and then guess where to put the new attachment holes. My statement to "guess" where to move the fairings is an assumption that they were located correctly to begin with. If one was to find a wheel pant or fairing that was not streamlined after rechecking this would be an easy fix, but if there isn't no "smoking gun" then it is more difficult to figure out which component to rework.

The only fairing that can be easily moved or adjusted without any major rework is the lower portion of the NLG fairing, which can be accomplished by loosening the lower hose clamp and twisting the fairing either to the left or right. I know this because I reinstalled my NLG lower fairing clamp first and then didn't notice when I was moving the upper intersection fairing so I could install the screws I was putting a slight twist into the fairing. This caused me a little head scratching to figure out why doing an oil change caused my ball to not be centered.
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  #23  
Old 11-16-2015, 06:43 PM
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N941WR N941WR is offline
 
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When and if you need a rudder trim, trying this idea from Tom Albano:



(Posted with Tom's permission.)
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  #24  
Old 02-25-2017, 12:27 PM
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jeffkersey jeffkersey is offline
 
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Default Any issues with it being attached to the plastic?

Quote:
Originally Posted by N941WR View Post
When and if you need a rudder trim, trying this idea from Tom Albano:



(Posted with Tom's permission.)
This looks like an easy, adjustable solution. How long has it been on? Any issues with it pulling the light loose and stripping out the plastic?

JK
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  #25  
Old 02-25-2017, 01:28 PM
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macrafic macrafic is offline
 
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Quote:
Originally Posted by Captain Avgas View Post
Top advice from Bill. A trim tab on an RV rudder is like a sign on the plane that says: "THIS AIRCRAFT HAS NOT BEEN BUILT PROPERLY".
Just saw a brand new Cirrus latest generation with a trim tab on the rudder. Must not have been built correctly?
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  #26  
Old 02-25-2017, 01:54 PM
jimbo jimbo is offline
 
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I haven't taken any survey but IMHO there are a lot of RV's flying out there that don't fly hands off because the builder doesn't want to put a trim tab on his RV that he spent years building to painstaking detail. Most RV's will fly hands off limping along at 100 Kts but crank it up to cruise speed and a wing might start to get heavy. Put the trim tab on and be happy. Obviously you have to check all the easy stuff first per Vans heavy wing fix it sheet instructions.

Jim
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  #27  
Old 02-25-2017, 02:36 PM
dtw_rv6 dtw_rv6 is offline
 
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I didn't want a trim tab in my rudder so I installed one gear leg fairing slight misaligned to center the ball. No one knows until I tell them.

Don
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  #28  
Old 02-25-2017, 02:51 PM
g zero g zero is offline
 
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Default Rudder

Quote:
Originally Posted by jeffkersey View Post
This looks like an easy, adjustable solution. How long has it been on? Any issues with it pulling the light loose and stripping out the plastic?

JK
Been flying two years and 150 hours with no problems.
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  #29  
Old 02-25-2017, 08:50 PM
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jeffkersey jeffkersey is offline
 
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Default Thanks for info!

Quote:
Originally Posted by g zero View Post
Been flying two years and 150 hours with no problems.
I might give it a try. How far out of center was you ball with out it? Di that amount center it up at cruise?
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  #30  
Old 02-25-2017, 10:38 PM
Schooner69 Schooner69 is offline
 
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Or... You could go the route my brother (-9A) and I (-7A) did...

http://www.aerosportproducts.com/ruddertrim.htm

A little more expensive that the triangular block I had on the rudder, but now I can trim for all flight conditions.

John
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