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  #1  
Old 05-16-2009, 06:35 PM
n5lp's Avatar
n5lp n5lp is offline
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Join Date: Apr 2006
Location: Carlsbad, NM
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Default Unlatch the canopy?

This is fresh in my mind because I changed tires today.

I am always amazed at how much the fuselage twists when using a wing jack. When the tip-up canopy is closed but not latched, this is obvious by the 3/8 inch or so gap that appears under one side of the canopy at the rear. Although I doubt if that is near enough to break a canopy I always make it a point to keep the canopy unlatched when using the wing jack so as not to twist it unnecessarily.

It doesn't look like the airplane would take anything like 6 gs if they were all on one side.
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  #2  
Old 05-16-2009, 07:31 PM
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L.Adamson L.Adamson is offline
 
Join Date: Apr 2005
Location: KSLC
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Default

Thanks for the heads up on this...

Does this mean I want to always use two wing jacks?

I built two for installing the fairings.

L.Adamson --- RV6A
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  #3  
Old 05-17-2009, 05:06 AM
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jsharkey jsharkey is offline
 
Join Date: Nov 2006
Location: Bennington, Vermont USA
Posts: 1,301
Default

Quote:
Originally Posted by n5lp View Post
This is fresh in my mind because I changed tires today.

I am always amazed at how much the fuselage twists when using a wing jack. When the tip-up canopy is closed but not latched, this is obvious by the 3/8 inch or so gap that appears under one side of the canopy at the rear. Although I doubt if that is near enough to break a canopy I always make it a point to keep the canopy unlatched when using the wing jack so as not to twist it unnecessarily.

It doesn't look like the airplane would take anything like 6 gs if they were all on one side.
I don't think that you can generate 6g "all on one side".

It would be interesting to know how much "roll torque" is needed and applied to the fuselage during max rate roll and roll entry. I suspect that it isn't much and that the differential wing loading is small when compared to the max g loading. To calculate you'd need to know the roll inertia of the aircraft and the maximum angular acceleration during entry and recovery.

Are there any other maneuvers that produce high asymmetric wing loading?

Jim Sharkey
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  #4  
Old 05-17-2009, 05:45 AM
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pierre smith pierre smith is offline
 
Join Date: Jan 2005
Location: Louisville, Ga
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Default The rudder twists the fuselage

,,,when you apply it fully. It's on one side of the fuselage and when you fully deflect it, obviously the airplane yaws but when it's full left rudder, the twist is in the opposite direction...clockwise. I know a guy who snap rolled a Globe Swift and broke the fin spar and laid it over at about a 45* angle.

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  #5  
Old 05-17-2009, 04:21 PM
PCHunt PCHunt is offline
 
Join Date: Feb 2007
Location: San Diego, CA
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Default Symmetrical vs. Rolling G

The 6G limit is only if the G-load is symmetrical, ie: little or no aileron or rudder input.
Typically rolling G limit is about 2/3 of symmetrical limits.
A loop should be symmetrical G, while a Barrel Roll would be rolling G.
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