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Step mounting instructions

Don

Don

Well Known Member
I'm ready to mount my steps and the manual refers to seperate instructions. I'm guessing they're an 8.5 x 11 page or pages. I can't find mine. :( If someone has them and they short enough could someone scan them and email them to me? It's curious to me that I can't find them because I thought I had kept every scrap of paper associated with the plane. Nonetheless, I can't put my hands on them and I'm at a point where I need them. Thanks for any and all help.
 
Add a doubler to the inside

After seeing a number of older RVs with 'working' steps, and after some discussion with other owners and builders, I decided to add a doubler to the inside of the fuselage skin. The doubler is riveted in assembly with the step and fuselage skin. There is a tremendous amount of stress on the step as one steps up and down.

Keith
N355RV RV9A
(steps on both sides!)
 
ksouthar said:
After seeing a number of older RVs with 'working' steps, and after some discussion with other owners and builders, I decided to add a doubler to the inside of the fuselage skin. The doubler is riveted in assembly with the step and fuselage skin. There is a tremendous amount of stress on the step as one steps up and down.

Keith
N355RV RV9A
(steps on both sides!)
Click to expand...
I just finished installing my steps this weekend so I have no flying experience to base this on. I thought about doing this very thing also but decided against it because I felt it would just add more weight without providing that much advantage in strength. I am sure there may be some shearing force on the rivets in the side skin but it seems to me that the long arm of the step that is then bolted to the polyurethane block (or whatever material that block is made of) which is then bolted to the baggage rib is taking the brunt of the force as one steps on the exterior arm of the step. It seems to me that the rivets in the skin are serving more to remove twisting forces (torque) on the step instead of shearing forces.

If I am incorrect in this assumption would some mechanical engineer please correct me on this issue.
 
Step longevity

To make sure that your steps last, never depart the plane like you are going down stairs. That is face first. Always back off the wing like you are going down a ladder. Going forward causes a high impact load on the step. Going backwards is much gentler on the structure.

Bruce Reynolds
RV-6A
 
Has anyone made folding steps for an RV, might be an improvement. The standard steps are a bit agricultural.
Steve Hill RV9a finishing.
 
"Retracting" Steps for RV

stevehilleo said:
Has anyone made folding steps for an RV, might be an improvement. The standard steps are a bit agricultural.
Steve Hill RV9a finishing.
Click to expand...
There are at least two different instances of "retracting" steps.

One was done by Mark Phillips ("Possum Works") on his award winning RV.
See http://websites.expercraft.com/n51pw/

Another has been offered as a mod you can purchase.
See http://www.stepupaviation.com/

James
 
stevehilleo said:
Has anyone made folding steps for an RV, might be an improvement. The standard steps are a bit agricultural.
Click to expand...
Hi Steve. What do you mean by agricultural? Every airplane step I've ever seen looks similar to Van's step.
 
Surface finish

Just a sideline point.

The vans steps have no surface protection and when that steel corrodes - it can be difficult to remove from the step structure and weldments when inplace on the aircraft.

Prime and paint before final fit if you get the chance.

Spent my weekend with scotchbrite and a steel primer instead of flying.

Duncan
 
Steve:
The rivets mounting the step to the fuselage are providing clamping force (tensile load) and serve to resist sliding of the plate over the fuselage (shear loading). The torque tube actually serves to resist motion in the vertical plane (with the fuselage skin as the pivot point). If the torque tube reaches a point where it is actually resisting torsion, then the rivets have failed and you need to remove the step. Best point from previous posts was from Bruce Reynolds. Also, remember to prime entire step weldment, especially between step and fuselage, to prevent galvanic corrosion.
Terry
(Metallurgical, not mechanical)
 
terrykohler said:
Steve:
The rivets mounting the step to the fuselage are providing clamping force (tensile load) and serve to resist sliding of the plate over the fuselage (shear loading). The torque tube actually serves to resist motion in the vertical plane (with the fuselage skin as the pivot point). If the torque tube reaches a point where it is actually resisting torsion, then the rivets have failed and you need to remove the step. Best point from previous posts was from Bruce Reynolds. Also, remember to prime entire step weldment, especially between step and fuselage, to prevent galvanic corrosion.
Terry
(Metallurgical, not mechanical)
Click to expand...
Thanks for the explanation. In my installation I noticed there was a considerable amount of force being placed on the polyurethane block the step tube inserted in. It seemed to me that long arm attached to the baggage floor rib was taking on the brunt of the force rather than the rivets in the skin. This is why I decided against installing a backing plate inside the skin where the rivets attach. I figured that would just be adding weight without adding much additional support. Does anyone else have input on that idea that was brought out in the previous post?

I have already installed the steps on my plane. I did prime (but did not paint) the entire step prior to installation with the idea that rust would easily develop in between the skin and step plate or on any of the welds. I also primed the skin surface underneath the plate. Hopefully this will be enough to keep rust and/or corrosion from setting in.
 
Sealing step flange to fuselage skin

It seems that there is a possibility for water penetration between the step flange and the fuselage skin unless some form of sealant (such as proseal) were used during installation.

Has anyone considered/done this?
 
YUP and no

If I were doing this again I would definatly use proseal between the plate and the fuse...When I was painting I was wet sanding the primer and then niticed a nice rust stain coming from behind the step...Lovely! And yes i did prime it.

What i did was to use blue masking tape and masked a 1/8th wide gap all around the edge of the step plate and op to the edge on the plate istelf.

Then daubed proseal in the gap between the tape and smoothed with a posicle stick.

Removed the tape and the line of proseal painted over just fine.

Airplane has seen flying in lots of rain in the last 100 hours and its holding up great.

A lot easier to slurp some behind the plate before you mount it though!

Frank
 
ProSeal instead of primer?

When I get to that point, I want to have a thin layer of ProSeal between the plate and the skin. Since ProSeal should not be used over primer, will it inhibit corrosion between the steel and aluminum on ts own? I'm thinking yes, but does anyone really know?
 
doubler size

it would seem to me a doubler would need to be larger and have more rivets than the steps themselves to benifit the side skin much.it looks to be a shear load and rotational on the vertical plane. unless the doubler has additional load spreading capabilities(more rivets ) seems a waste of time.
the back off method does seem much more kind to the aircraft. ive seen people simply walk down as mentioned and really makes me flinch.
look at alot of old aircraft and you will likely see many repairs of the steel rather than the alu. do certs have doublers?
 
My step installation

Well, thanks to all the posts over the past couple days, I decided to go ahead and tackle my steps. I took the advise of some and primed everything. I also painted the exterior portions of the steps. I decided against the proseal, opting for the primer instead.

Primed exterior skin.


Interior installed view.


Exterior installed view.
 
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