RV-6A Step Repair:
During my first annual conditional inspection, at around 100 hours flight time, I found a crack on the passenger side step in the same location reported by many RV builders/owners. The pilot side step, which gets a lot more use, was fine and even as I write this at about 200 hours total time it shows no sign of cracking. Considering the 40 hours of Phase I (therefore solo) test flight (slightly more than 40 for my RV) included in that first 100 hours and the fact that a large number of those remaining 50-some hours before I found the crack were also solo, I'm pretty well convinced that the cracks are due to the harsher abuse typical passengers can subject the step to.
I know some RV owners have had the pilot side crack too so I'm watching that carefully but in looking at a few other flying RVs, I've found the same situation with cracked passenger side step and good pilot side step. In one case the owner hadn't found the crack yet and one was a plane that had a history of owners/pilots heavier than me but with no crack on pilot side step.
I've always been very careful not to bounce or drop onto the pilot side step and try to always step as far inboard on the step as possible. That seems to have kept my pilot side step in good shape.
Prior to the crack appearing in my passenger side step, the most frequent passenger in my RV was my teenage son who weighed at the time about the same as me and he always complied with my careful coaching about being gentle on the step. He's over 6' 1" tall and has long legs, so he now just steps onto the wing and doesn't use the step at all.
So where I think my step probably sustained the damage is with a handful of passengers over the 200 lb mark and maybe a dozen Young Eagles during EAA Young Eagle events in that first year my RV was flying. No way to know for sure, but that's my theory. I explain to all passengers how to get in and out using technique that minimizes stress on the step, but I guess it's hard to remember after the flight and it's definitely hard to temper the excitement / enthusiasm of some of our Young Eagle kids. Heavier passengers tend to "drop" onto the step and the kids tend to jump or "bounce" down and out of the plane. I'm somewhere in the low twenties on number of kids flown in my RV now and will continue to fly them with the EAA Young Eagles program, but I now ask them to remain seated after shutdown until I can get out of and around the plane to help them, and that has helped me minimize the stress on the step.
I also have a small folding wooden step stool I bought from Aircraft Spruce that weighs about 4 lbs and fits nicely in the baggage compartment. That comes in handy for less mobile and/or heavier passengers.
The cracking starts on the bottom side of the step on the streamlined tubing just below the weld to the plate that is riveted onto the fuselage skin. That's the area in compression when the step is in use. Below are some pictures of the crack on my passenger side step from a few different viewpoints. The rust spots you see are where the 4130 steel started to surface rust through the primer coat I had put on to cover the steel until I got the RV painted (happening Dec 2010 - Jan 2011). This is the view from the bottom of the step, so the tube extending to the right in the picture is the torque tube that goes inside the fuselage under the baggage compartment floor:
Removing the step from the RV fuselage is not a simple task. I installed my baggage compartment floor per plans, which means it is pop riveted in place. Some builders choose to use screws and nutplates to install baggage compartment floors to make them removable. Even after this I didn't want to put in that many nutplates but I did cut two access holes in the floor near the torque tube bolts and installed reinforcement rings with cover plates so I can remove the step in the future without having to remove the entire floor. Drilling pop rivets can be very frustrating as the manufactured heads tend to spin with the drill, so I invested $75 in this pop rivet removal tool from Avery's Tools and it made things very simple by holding the rivet head in place to prevent spinning (was also useful in speeding up the solid rivet removal when I drilled the step to fuselage rivets):
See the next page, Page 38, for pictures of the repair and reinstallation.
This page was last updated on 12/18/11.
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