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06-05-2014, 11:47 PM
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Join Date: Mar 2007
Location: McKinney, TX
Posts: 1,261
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My step cracked.
I was under the plane doing some work and happened to creep by the step and thought that seems to have more movement than I remembered.
Sure enough the back side right at the weld and gusset is a crack, just logged 216 hours. Step stool used when in the hangar so it is only used when getting in and out for flight. I always step back onto the step and have my passangers do the same.
This well be kind of a big job as I cut my flap fairing to just fit the step, the flap fairing will have to come off or at least part of it. then all those rivets to remove, I know a good welder and will ask if this is something that can be done with the stop on the plane.
I wonder if a wad of JB Weld would hold things for a few months, I really don't want the airplane down for the summer flying season.
Cheers
These are photos of the crack and step and fairing.

__________________
Mike "Nemo" Elliott
RV-8A (First Flight 12-12-12!)
KOCF
N800ME
www.mykitlog.com/rvg8tor
Dues Paid 2019
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06-06-2014, 01:04 AM
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Join Date: Jul 2008
Location: Santa Rosa, CA
Posts: 580
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A gusset?
Looks like the added gusset created a stress point and didn't allow the tube to bend naturally.
Steve
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06-06-2014, 06:00 AM
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Join Date: Jul 2010
Location: Novi, MI & Venice, FL
Posts: 66
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I took a continuing education course titled "Fatigue of Weldments". One thing the professor said that has always stayed in my mind is that weldments are instruments of the devil. I know many who have had similar failures. It can't be repaired as all you'll be doing is chasing the crack to some other location near the affected area. We need to design a step that does not have welds, at least in the portion where the step attaches to the tube.
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Rich Bond
Just a wishful observer
Gave up awaiting AOPA/EAA exemption request
2015 =VAF= Contributor
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06-06-2014, 07:26 AM
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Join Date: Jun 2006
Location: 8I3
Posts: 3,564
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It is mind-boggling that step cracks continue to be a problem that the factory never has had an interest in addressing. "When in doubt build it stout". Doubling the thickness of the steel parts in the steps 2x would solve the problem. Who cares if it gains two pounds in weight.
__________________
Please don't PM me! Email only!
Bob Japundza CFI A&PIA
N9187P PA-24-260B Comanche, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
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06-06-2014, 08:56 AM
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Join Date: Jan 2005
Location: Auburn, WA
Posts: 668
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Hi Mike. Kind of a bummer I know. I had the same thing happen to my 9A at about the same time. I watched it carefully and in my case it never extended much further than what you show. When I sold it at 700 hours it was still holding and I never dealt with it.
Your JBWeld idea should keep it from flexing if you grind down the outside, but won't really "repair" it. Only true solution is to remove for repair long term.
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Andy Karmy
Covington WA
RV-8 - Flying!
RV-9A - sold
Dec 2019 Paid
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06-06-2014, 09:23 AM
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Join Date: Mar 2007
Location: McKinney, TX
Posts: 1,261
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Interesting
Quote:
Originally Posted by akarmy
Hi Mike. Kind of a bummer I know. I had the same thing happen to my 9A at about the same time. I watched it carefully and in my case it never extended much further than what you show. When I sold it at 700 hours it was still holding and I never dealt with it.
Your JBWeld idea should keep it from flexing if you grind down the outside, but won't really "repair" it. Only true solution is to remove for repair long term.
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Andy,
Funny you should say that, I wondered if the crack is done moving and if it has been there a long time. I say this because the good side now kind of acts like a hinge, when weight is on the step it compresses but when off it just relaxes.
My plan is to baby it until winter when I can tackle the real issue, I might just try a new design I was thinking about when building. I was thinking of a telescoping tube system that would stow flush to the fuselage. This would give me a step that will not crack and less drag!
Cheers
__________________
Mike "Nemo" Elliott
RV-8A (First Flight 12-12-12!)
KOCF
N800ME
www.mykitlog.com/rvg8tor
Dues Paid 2019
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06-06-2014, 09:34 AM
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Join Date: Mar 2009
Location: Grand Rapids, MI
Posts: 1,004
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Quote:
Originally Posted by RVG8tor
Andy,
Funny you should say that, I wondered if the crack is done moving and if it has been there a long time. I say this because the good side now kind of acts like a hinge, when weight is on the step it compresses but when off it just relaxes.
My plan is to baby it until winter when I can tackle the real issue, I might just try a new design I was thinking about when building. I was thinking of a telescoping tube system that would stow flush to the fuselage. This would give me a step that will not crack and less drag!
Cheers
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Would love to see a design for a telescoping tube step! Might just have to put some time into this and make a project out of it! Anyone? Alan?
__________________
Paul K
West Michigan
Unfortunately in science, what you believe is irrelevant.
2020 donation made, exempt but worth every dime!
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06-06-2014, 09:42 AM
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Join Date: Oct 2008
Location: Lake Country, B.C. Canada
Posts: 2,416
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....better than steel?
Quote:
Originally Posted by rocketbob
It is mind-boggling that step cracks continue to be a problem that the factory never has had an interest in addressing. "When in doubt build it stout". Doubling the thickness of the steel parts in the steps 2x would solve the problem. Who cares if it gains two pounds in weight.
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If the steel is such a problem, why not an aluminum, or ( gasp!) carbon fibre step? surely one of the keen vendors on VAF could come up with a part that is actually stronger, lighter, and faster than they were before!
(...cue 6 million dollar man musical interlude here...) 
__________________
Perry Y.
RV-9a - SOLD!....
Lake Country, BC
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06-06-2014, 09:52 AM
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Join Date: Dec 2009
Location: Boulder, CO
Posts: 4,435
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JB Weld is a poor idea. It can't pick up enough load to do any good since its modulus of elasticity is no more than 1/40 of the steel. All it will do is hide the crack.
Dave
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06-06-2014, 09:55 AM
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been here awhile
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Join Date: Dec 2004
Location: North Alabama
Posts: 4,301
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Quote:
Originally Posted by RVG8tor
My plan is to baby it until winter when I can tackle the real issue, I might just try a new design I was thinking about when building. I was thinking of a telescoping tube system that would stow flush to the fuselage. This would give me a step that will not crack and less drag!
Cheers
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This has been done. A builder in Tennessee has a RV-6A he built several years ago with retractable steps. They are linked to the canopy with cables so they extend when the canopy is opened. One of the cleverest mods I've ever seen...and I have no idea how he did it.
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