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Discover
Joined: 26 Feb 2007 Posts: 429
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Posted: Wed Sep 26, 2012 6:00 pm Post subject: Aileron Counter Balance Weight |
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Anybody here know why the Tiger Aileron Counter Balance Weight has to hang out the bottom of the wingtip? What a draggy piece of engineering.
Was there some design reason for that or was it just an oops? Also why 3-lbs on a 6" tube instead of 1.5-lbs on a 12" tube?
Looks like either of those lengths would fit inside the wingtip if the holes had been drilled in the "right" place.....
Ned
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n76lima(at)mindspring.com Guest
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Posted: Wed Sep 26, 2012 6:46 pm Post subject: Aileron Counter Balance Weight |
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Quote: | Anybody here know why the Tiger Aileron Counter Balance Weight has to hang out the bottom of the wingtip?
What a draggy piece of engineering. Was there some design reason for that or was it just an oops?
Also why 3-lbs on a 6" tube instead of 1.5-lbs on a 12" tube?
Looks like either of those lengths would fit inside the wingtip if the holes had been drilled in the "right" place.....
Ned
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The counterweight doesn't hang out in the slipstream except when the aileron is deflected UP.
If yours is not flush to ~3/8" inside the tip when the aileron is centered in the trail position, then Tiger LLC screwed up (again) and mis-drilled your aileron counterweight holes in the torque tube. This is actually a fairly common rigging failure, that is seen across American, Grumman, Gulfstream, AGAC AND Tiger LLC. Kinda like how they didn't get the elevator halves aligned when they were drilled into the control horn... another common factory screw up that seriously messes up the rigging. I've fixed dozens of them. It messes up the stop geometry because one of the bolts that holds the aileron counterweight on is also the moving part of the aileron stop assembly. If it is clocked wrong, then it hits the stop too soon one way and too late the other.
Back to the story...
When the aileron goes UP the opposite one is going down. Remember your PPL training? This causes ADVERSE YAW that you must counter with the rudder.
By having the weight come out of the wing tip and into the slip stream, it creates some drag on the down going wing, helping to decrease the adverse yaw from the opposite aileron. Its not a bug, its a feature.
As for the length of the arm and the amount of the weight, a longer arm would have required a larger, stiffer tube to support it.
I wasn't there for the planning meeting, but a lot of little compromises were made, and perhaps this was one of them, where they gave up the weight increase to have a drag DECREASE due to the smaller hole in the bottom of the wing tip???
--Bob Steward
Birmingham, AL
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Discover
Joined: 26 Feb 2007 Posts: 429
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Posted: Wed Sep 26, 2012 7:22 pm Post subject: Aileron Counter Balance Weight |
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So if my counterweight didn't go out the bottom of the wingtip then I might have to pick my feet up off the floor once in a while???
Hmmm
On Sep 26, 2012, at 9:46 PM, n76lima(at)mindspring.com wrote:
Quote: |
> Anybody here know why the Tiger Aileron Counter Balance Weight has to hang out the bottom of the wingtip?
> What a draggy piece of engineering. Was there some design reason for that or was it just an oops?
> Also why 3-lbs on a 6" tube instead of 1.5-lbs on a 12" tube?
> Looks like either of those lengths would fit inside the wingtip if the holes had been drilled in the "right" place.....
> Ned
The counterweight doesn't hang out in the slipstream except when the aileron is deflected UP.
If yours is not flush to ~3/8" inside the tip when the aileron is centered in the trail position, then Tiger LLC screwed up (again) and mis-drilled your aileron counterweight holes in the torque tube. This is actually a fairly common rigging failure, that is seen across American, Grumman, Gulfstream, AGAC AND Tiger LLC. Kinda like how they didn't get the elevator halves aligned when they were drilled into the control horn... another common factory screw up that seriously messes up the rigging. I've fixed dozens of them. It messes up the stop geometry because one of the bolts that holds the aileron counterweight on is also the moving part of the aileron stop assembly. If it is clocked wrong, then it hits the stop too soon one way and too late the other.
Back to the story...
When the aileron goes UP the opposite one is going down. Remember your PPL training? This causes ADVERSE YAW that you must counter with the rudder.
By having the weight come out of the wing tip and into the slip stream, it creates some drag on the down going wing, helping to decrease the adverse yaw from the opposite aileron. Its not a bug, its a feature.
As for the length of the arm and the amount of the weight, a longer arm would have required a larger, stiffer tube to support it.
I wasn't there for the planning meeting, but a lot of little compromises were made, and perhaps this was one of them, where they gave up the weight increase to have a drag DECREASE due to the smaller hole in the bottom of the wing tip???
--Bob Steward
Birmingham, AL
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teamgrumman(at)yahoo.com Guest
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Posted: Thu Sep 27, 2012 10:00 am Post subject: Aileron Counter Balance Weight |
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I had a customer with a plane that had been painted and then had the ailerons properly weighed and balanced. The tips of both had been cut off by about an inch. Guess you could shave one side as well.
I've also seen some planes where the weight hangs noticeably lower on one side than the other with the ailerons neutral.
I've also seen deformed wingtips and, with the aileron neutral with respect to the wing, the wingtip was noticeably higher on one side.
Quality control was not a priority.
BUT, all of the FAA/PMA paperwork was properly signed.
From: 923te <923te(at)att.net>
To: Team Grumman <teamgrumman-list(at)matronics.com>
Sent: Wednesday, September 26, 2012 6:59 PM
Subject: Aileron Counter Balance Weight
--> TeamGrumman-List message posted by: 923te <923te(at)att.net (923te(at)att.net)>
Anybody here know why the Tiger Aileron Counter Balance Weight has to hang out the bottom of the wingtip? What a draggy piece of engineering.
Was there some design reason for that or was it just an oops? Also why 3-lbs on a 6" tube instead of 1.5-lbs on a 12" tube?
Looks like either of those lengths would fit inside the wingtip if the holes had been drilled in the "right" placsp; -================
[quote][b]
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