Cracking on steps

[ppilotmike]

[quote=bruceh;1020347]I was under my RV-9A tonight cleaning the belly and lo and behold, the passenger side step has a small crack. This is at 183 hours. QUOTE]

Sorry to hear that.

Originally Posted by bruceh

I haven't painted the airplane,

So, I assume there's no primer on it then..

Originally Posted by bruceh

Does anyone have a definitive protocol for getting this fixed.

Step one.. Get a non-certified, non-primered, chocolate chip cookie...

P.S. This is a "thread bomb." See http://www.vansairforce.com/communit...d.php?t=130389

[boom3]

Originally Posted by posterman

Perhaps this has been mentioned before but all the 6's & 7's I have seen with cracked passenger steps were on aircraft where passengers routinely faced towards the rear of the aircraft and stepped down when exiting instead of facing forward and backing out by placing their left foot on the step.

Has anyone else observed this correlation?

It's a great idea to instruct passengers how to climb in and out of the airplane properly but I don't believe it's the reason most of them crack.

I think vibration has the most to do with it and the fact that they are under engineered. Notice that even Vans beefs up the steps on their own airplanes.

Why Vans chooses to do nothing about it year after year baffles me.

[ppilotmike]

Originally Posted by boom3

It's a great idea to instruct passengers how to climb in and out of the airplane properly but I don't believe it's the reason most of them crack.

I think vibration has the most to do with it and the fact that they are under engineered. Notice that even Vans beefs up the steps on their own airplanes.

Why Vans chooses to do nothing about it year after year baffles me.

How did they "beef up" their steps?

[David Paule]

Originally Posted by boom3

I think vibration has the most to do with it....

It's not vibration. The design has a sort of secondary local bending which I think is the cause.

Dave

[boom3]

Originally Posted by ppilotmike

How did they "beef up" their steps?

From post #6 at the beginning of this thread. (From Russ the step manufacturer for Vans.)

I would recommend any one having problems with this, weld a strap on the bottom side that extends down about two inches, Vans actually does this on there demo planes because people of all sizes climb in and out of them all day long all the time.

[vasrv7a]

I agree and seriously doubt that stepping on the passenger step either way has any effect on how our steps have been cracking. Per photos posted by others, my passenger step has cracked exactly the same way and I don't have too many passengers that fly with me on a regular basis. So the passenger step is not used often, yet my pilot step has no cracking so far and I have been using the pilot step almost weekly for about 9 years (about 700 hrs). Also, I always supervise each passenger while they step up onto the wing and enter the cockpit as well as fully supervise how they exit the plane and step down off of the wing, and no one has ever stepped down facing the rear of my RV, they all have faced forward per my instructions... My supervision is mostly related to passenger safety.

If the cause of the passenger side step cracking is related to propeller pulse vibration, etc. as many on this forum have suggested, because there really is no standard configuration of engine/propeller (engine horsepower, 2 blade vs 3 blade props, fixed vs CS props, metal vs whatever material) there may not be a way to zero in on the actual culprit. And some on this forum have reported both steps have cracked, some even have reported that steps have cracked on an RV that has not yet flown??

Welding a support onto each step (or at least the Passenger step) as Vans has done seems to be the favored solution, and this solution seems to have worked. Friends of mine who are engineers (structural and mechanical) have looked at the problem and suggested removing the step from the airplane and slicing open the step and the tube that goes inside the fuselage and inserting and welding in an I-Beam like support. They claim that this I-Beam type of support should eliminate the vibration and make the step much stronger. The mechanic who is currently doing my condition inspection agreed that the I-Beam would be a good fix. Some other RV owner on this forum posted photos of exactly this solution, and my mechanic did pretty much the same type of fix on my passenger step.

This work on my step was recently completed and the step is currently being painted... I hope and expect that this solution will solve the step crack problem, and if the pilot side step shows the same crack, we'll probably use the same solution.

Victor

[bruceh]

I'd love to just take off the steps, ship them to someone who would weld up the reinforcements and ship them back.

[ArVeeNiner]

Alan from AntiSplat has a theory that the cracking is caused by vibration. He has suggested drilling a hole in the step and adding some sand to damp out the vibration before a crack occurs. IIRC I think he's done it for several of his friends.

I went ahead and added sand to my steps. So far no cracks. I figured it couldn't hurt.

[MikeyDale]

I added sand then welded up the hole. Guess we will see. I kinda wished I would have taken them off my taildragger, I really dont use the one on the left side cause every time I start to step on it I think of all the problems everybody has and just step across it.

[KTM520guy]

The problem with the step is the gusset. When you step down a lot of stress is placed at one small spot. That's where the crack starts.



The stress needs to be spread over a larger area. A doubler installed in the area in the picture will solve the problem.