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Step Weldament Failure Warning

Bob Kibby

Well Known Member
The pilot side step (WD-1233-L) failed as I started to man the aircraft. WD-1233-L fractured at the lower end of the welds on both sides of the channel that mounts the step to the fuselage. The step did not separate completely and ended up hanging from the bottom of the airplane. I removed and inspected the right side step. WD-1233-R appears to a small crack at the end of each of the 2 welds where WD-1233-L failed.
Other than being surprised by the step disappearing under me there wasn?t any problem. If the step had failed when I was exiting the aircraft then I might have had a problem.
I?ve submitted a RV-12 Feedback Form (Safety Alert) to Van?s Engineering this morning but I wanted to get the information out so you can take necessary precautions when getting in and out of the airplane.
I am 6 ?5? tall and weigh 215 lbs so the pilot?s side step does get a work out. I am trying to confirm that there are cracks on the passenger step since it doesn?t get the weight and cycles that the pilot side does. I?ll update the passenger step information when I get an expert opinion. The aircraft has logged 268 hrs over 380 flights.
Bob Kibby ?N712BK?
 
Thanks for the heads up. That step and its attachment is an area of concern for me, since I will give mine even more of a workout. So far so good, but let's just say I'll be making it a regular inspection item as I also work to reduce the load on the step.
 
I saw one previous post of a step failure. Is there any indication of a manufacturing issue?

I am about the same weight and have a similar number of cycles, so this concerns me.
 
The issue is being investigated based on a previous report (not sure if it was John).

In the mean time, hopefully people are aware that they should be either climbing off of an RV-12 (actually any RV model for that matter) backwards as they would when climbing down a ladder..... or if fwds.... that they are stepping lightly down onto the step.

Most people, if they stand on the wing of any RV and step down facing fwd, will be shock loading the step much higher than the load they apply climbing up (up to 2.5 X's or more).
 
Good to hear the issue is being looked at and evaluated. I have seen posts in the past about the step failing and modifications done by others. As I recall it involved welding addition structure to the step to endure the weight and repetition the step gets.

Knowing of these past failures I make an effort to minimize the direct weigh distribution on the step when climbing in and out. Hopefully I will see some better longevity until a modification is developed. Be careful!!
 
It was me - -

I posted my fix way back when. I am 210 - 215#. I am in pretty good shape, and briskly get in and out of my 12. I advised back then that if you were more than say 200#, you need to think about it. I nearly made it to the ground ( with ZERO preparation ! ).
 
As an admitted and confirmed member of the Heavy Lift Club, I take extra care to get in and out as gently as possible, never plop down onto the step as rvbuilder2002 mentioned, and try to keep as much weight as I can on the cockpit side and/or other structures.

And, yeah, I'm losing weight too, but realistically there's only so much you can do. The last time I was under 200# was during Basic Training in 1979.
 
Yup same thing happened to mine a couple years ago. I reinforced both the left and the right step. Its been OK since then.


Brad Stiefvater
Salem SD
 
"2BK" RV-12 Entry and Exit Procedure

To exit the RV-12 aircraft, I turn around backwards, sight the step between my legs and put my left foot on the step before transferring my right foot to the ground. I also coach any passenger to use the same approach and have them put their right foot on the step and then left foot to the ground. For passengers that need extra help getting in and out, I have a fold up step from The Container Store (rated at 250 lbs 12" high) that I use as an intermediate step between the RV step and the ground. This really helps entry and exit if someone has a bad knee or hip. To get in or out of an RV-7 (tail dragger) I have to use The Container Store step. I also have to cross my legs in the RV-7 to get them under the instrument panel.

Glad that Van's Engineering is looking into the problem.

Bob Kibby (N712BK)
 
I have searched and cannot find it, but, there was a detailed description of how to get in and out of an RV-12. If I am not mistaken, it was composed by the man himself. Not sure if it was posted in the RVator, or in an old revision of the PAH. Basically it says that it is not necessary to step on the wing at all. As strange as it may sound, you actually step up on the step with your forward foot, then step into the cabin floor with your aft foot, step in standing up, then sit down. This may sound ridiculous, and on your first attempt, you will probably want to dismiss it. Don't! Try it several times. It works. I am 6 foot, 195 lbs, and 77 years old. My wife is 5 foot 3, and 75, and weighs ???. We both use this method and it works perfectly. My step is working great! Wish I could find the write up. Oh well.......Old age.....What can I say...........Tom
 
I think I'll give the step extra attention at annual and possibly beef it up a bit. I also make an effort to not put my full weight on it.
 
Identical Step Failure

My pilot step broke exactly in the same place as JBPilot. It is at the end of the last weld on both sides of the U channel. It appears to me that there is a stress concentration at that point and it is just a matter of cycles before the step breaks. There is no way you can inspect for a crack in that area without removing the step. Still waiting to show my passenger side step to a structure's guru to confirm that I have cracks starting at the end of the same welds.

I had not seen JBPilot's earlier post about his step failure. With as many RV-12 pilots reporting broken steps it is amazing that someone someone hasn't been hurt.

Bob Kibby (N712BK)
 
Seems like I see most experienced RV crew going backwards on those steps. And treating them gently. The standard 170 lb. pilot is long gone from this planet and is apparently not coming back. If you fall, due to a failure... you will do much less damage to yourself if facing backwards. Good luck
 
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The standard 170 lb. pilot is long gone from this planet and is apparently not coming back.
I don't know that there ever was a 170# "standard" for pilots, was there? Isn't/wasn't that a number for the average passenger... including kids, teenage girls and guys like me? Maybe I'm wrong, I don't know. I just averaged out the weights of myself, my wife and some friends... it came out to 173#, which is pretty close. But none of the guys are anywhere near that.
 
The FAA allowed commercial operators to use 170 lb. per person for decades to save weighing dozens of pax on a flight before doing a departure weight & balance. A few years ago a Beech 1900 fully loaded with 19 male pax and two crew took off (at KATL?), entered a steep climb, stalled and crashed killing all. The NTSB found the airplane was over gross with the CG beyond the aft limit. Today the standard person weight is something like 190 lb. and the standard weights for carry-ons also increased.
 
Special instructions

Are you telling us that In the mean time we should follow your Special Instructions. Is this your recommendations or van's

This has been a problem for some time

I think van's should do a recall before someone gets seriously hurt.

For you guys who weld or reinforce it on your own you are moving the liability from vans

I will not install my steps until van's have finished their review

Joe Dallas







The issue is being investigated based on a previous report (not sure if it was John).

In the mean time, hopefully people are aware that they should be either climbing off of an RV-12 (actually any RV model for that matter) backwards as they would when climbing down a ladder..... or if fwds.... that they are stepping lightly down onto the step.

Most people, if they stand on the wing of any RV and step down facing fwd, will be shock loading the step much higher than the load they apply climbing up (up to 2.5 X's or more).
 
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Are you telling us that In the mean time we should follow your Special Instructions. Is this your recommendations or van's

Joe, I am saying that regardless of the situation, no one should be jumping/dropping onto the step of an airplane..... Regardless of the model.
It is not special instructions. It is common sense.

It is my personal recommendation.
If you want an official one you can call or e-mail, and talk to someone in the office.
They will likely tell you the same thing.
 
After two years of getting in and out I could not remember the details of how I proceed after reading this thread. Yesterday I did my exit in slow motion and mindfully. What I noticed is while facing the back with two feet on the wing, I grab the roll bar with my left hand and lower myself slowly to bring my left foot on the step. This allows to load the step progressively and prevents the dynamic load mentioned earlier. Only when my left foot bears all my weight do I release my hold on the roll bar to bring my right foot on the ground.

I am tempted to suggest that VANs include such instruction in the pilot hand book but, after a previous thread (*) answer I expect to be told that "if you are not able to get out of the plane you have no point getting in".:rolleyes:


(*) http://www.vansairforce.com/community/showthread.php?t=130923
 
I don't quite understand the level of discontent being expressed in this thread. I don't know about anyone else, but I look at the general size, weight and intent of the airplane and just assume that the step is not "up-armored" and designed for guys like me. I'm not surprised that over time you can, if not careful, cause it to crack. I'm happy that one possible solution has been posted. If Van's comes out with an upgraded step design, great - I may buy a pair. If not, I'll treat mine as gently as possible, watch for signs of fatigue and be ready to fix or replace them if they break.
 
Hi Dale - -

We are not a long ways apart. Sometime we should meet mid-state and if you step on both steps one after the other, you will likely be surprised how much different they feel. If heavier pilots are fully aware of the potential, and talking about it here helps that, then it can be up to the individual. I obviously still very much like my RV-12. There have been a few things that have needed to be undated and this is one to be aware of. Overall a great plane. A few additions and mods make it even better.
 
John, I would love to meet somewhere. I'm in the middle of a little refurb effort here -- wings and wheel pants off, tank out, seats and carpet out, but I'm starting to re-assemble and hope to get some flying in before the weather gets really cold.
 
Design the step based on good engineering practice

In my view van's should finish their testing and see if it meets the requirements of anticipated loads
The load of a 250 pound pilot and dynamic loads and a reasonable safety factor
Special instruction for getting in and out of a aircraft is ludicrous
The owner can use common sense as Ken suggested, however the people who get in and out should not have to take lessons on how to not educe dynamic loads
Design the step based on good engineering practice


Joe Dallas



After two years of getting in and out I could not remember the details of how I proceed after reading this thread. Yesterday I did my exit in slow motion and mindfully. What I noticed is while facing the back with two feet on the wing, I grab the roll bar with my left hand and lower myself slowly to bring my left foot on the step. This allows to load the step progressively and prevents the dynamic load mentioned earlier. Only when my left foot bears all my weight do I release my hold on the roll bar to bring my right foot on the ground.

I am tempted to suggest that VANs include such instruction in the pilot hand book but, after a previous thread (*) answer I expect to be told that "if you are not able to get out of the plane you have no point getting in".:rolleyes:


(*) http://www.vansairforce.com/community/showthread.php?t=130923
 
In my view van's should finish their testing and see if it meets the requirements of anticipated loads

There is a huge difference between a structure being designed to take a specific load, and what can happen as a result of many many load cycles spread out over a period of time.

If we could find a person to climb on and off of a step all day long every day for a month, we might be able to test it to a level required to know what the long term durability is.

That is the context of pretty much all of the problems that have developed with the RV-12 (and other RV models as well). They are issues that show up with time in service. When they show up, attempts have been made to rectify them. This is pretty normal with any airplane that was ever designed.

The red prototype (N412RV) now has over 1600 hrs on it. It is carefully monitored to watch for the development of issues and a few SB's have been issued over the years based on that info. There has not been cracking of the steps like others have experienced (even though it gets probably a much higher level of entries/exits per flight hour than any other RV-12), but based on service history in the field, the step design is being reviewed.
 
After two years of getting in and out I could not remember the details of how I proceed after reading this thread. Yesterday I did my exit in slow motion and mindfully. What I noticed is while facing the back with two feet on the wing, I grab the roll bar with my left hand and lower myself slowly to bring my left foot on the step. This allows to load the step progressively and prevents the dynamic load mentioned earlier. Only when my left foot bears all my weight do I release my hold on the roll bar to bring my right foot on the ground.

I am tempted to suggest that VANs include such instruction in the pilot hand book but, after a previous thread (*) answer I expect to be told that "if you are not able to get out of the plane you have no point getting in".:rolleyes:


(*) http://www.vansairforce.com/community/showthread.php?t=130923

I finally found the Van's documented recommended method for entering an RV-12. It is what we use, and it works very well without adding extra Gs to the step. It is listed in your Flight Training Supplement. Check your manual for additional methods, but this works for for us. It does take a few tries to get comfortable with it, but it is worth the trouble. As they say, when all else fails, read the manual!! Here it is:

Revision: 2 Date: 04/03/14
RV-12 Flight Training Supplement 5-3
ENTRY & EXIT TECHNIQUE How to get in & out. Entry method 1: Stand just forward of the wing leading edge facing the cabin. Step up onto the boarding step with your leg that is closest to the front of the aircraft. Place the hand closest to the rear of the aircraft onto the roll bar. Bring your other leg over the cabin deck and place your foot on the non-skid area just forward of the seat. Then move your foot from the step to just forward of the seat and then sit in the seat.
 
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I finally found the Van's documented recommended method for entering an RV-12. It is what we use, and it works very well without adding extra Gs to the step. It is listed in your Flight Training Supplement. Check your manual for additional methods, but this works for for us. It does take a few tries to get comfortable with it, but it is worth the trouble. As they say, when all else fails, read the manual!! Here it is:

Revision: 2 Date: 04/03/14
RV-12 Flight Training Supplement 5-3
ENTRY & EXIT TECHNIQUE How to get in & out. Entry method 1: Stand just forward of the wing leading edge facing the cabin. Step up onto the boarding step with your leg that is closest to the front of the aircraft. Place the hand closest to the rear of the aircraft onto the roll bar. Bring your other leg over the cabin deck and place your foot on the non-skid area just forward of the seat. Then move your foot from the step to just forward of the seat and then sit in the seat.

I had no knowledge (my mistake) of this document full of interesting tips. Thanks for your research and finding, another one to put on VAF's credit.
 
I believe it is provided to all builders in the documentation package with the Maint. Manual, PAP, and other documents.
 
Question

How does it make any difference in the load on the step if you exit directly from the cockpit to the step or the wing to the Step? I'm not talking about jumping from one to another but a normal transition of the load from one foot to the other. Doesn't pass the smell test for me that it makes any difference.
Bob Kibby N712BK
 
How does it make any difference in the load on the step if you exit directly from the cockpit to the step or the wing to the Step?

It doesn't.

That procedure isn't in the flight training supplement because it is the least abusive on the steps, it is there because it is one way that works. A process needed to be described for the document and that is the one that the author chose.
It is not the one that I (and other pilots I know) use.....
 
I don't think that the step is being abused when getting in. I think it may be happening when exiting. With the above procedure, you won't see the step, and you will gracefully feel for it, as you gently lower your first exit foot down to it. We use, and like this method.
Tom
 
Vans Review

Ken You are correct
That is why I said (Design the step based on good engineering practice )
And in post #18 - I said (I will not install my steps until van's have finished their review )
I think that the design is on the light side of safety ( the cutout for a flat surface is a question in my view )
I have not seen any photos of the failure or do I have any idea of the number of affected steps.
I think that there are 500 or more sets of steps sold and it would be a expensive to replace them all,
However to keep building all the new steps the same may not be prudent in my view.

And as I stated in post #24 Special instruction for getting in and out of a aircraft is ludicrous.

This is not the way to handle a design deficiency, if there is one
My View

Joe Dallas





There is a huge difference between a structure being designed to take a specific load, and what can happen as a result of many many load cycles spread out over a period of time.
 
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Once again I am reminded of the words a professor used in a Fatigue of Weldments class that I was taking - "Welds are instruments of the devil". Estimating the fatigue life of a welded structure is among the most difficult tasks in engineering.
 
Another short step!

Thanks for the reminder about exiting backwards. I have exited forwards many times, I thought gently, certainly not jumping on the step.

Recently the step failed when I was climbing in. Not a complete separation but a bend which caught me by surprise. I got the step welded and have purchased a replacement as a spare.

I weigh less than 200 lbs, on a good day ;-)

Cheers...Keith
 
Do you have a photo of the bad step

I would like a review it



Joe Dallas


Thanks for the reminder about exiting backwards. I have exited forwards many times, I thought gently, certainly not jumping on the step.

Recently the step failed when I was climbing in. Not a complete separation but a bend which caught me by surprise. I got the step welded and have purchased a replacement as a spare.

I weigh less than 200 lbs, on a good day ;-)

Cheers...Keith
 
Sorry no pic. In fact the step was painted black so would be difficult to see the fracture.

Cheers...Keith
 
Step Weldament Failure Upate

Van?s replied to my step weldament Failure Feedback Form with an acknowledgement that ?the step has a propensity to crack over time?. Also, that Van?s has an open project looking into the issue but no timeline for the release of a new step. It was Van?s recommendation that I install another step of the current design in the interim.
I received my new replacement step weldament on 11/20/15. The new unpainted step has two small round bumps on the exterior in line with the U-channel on each side of the weldament which extends about 1 ? inches beyond the point where my step failed. These bumps may be evidence of tack welds to hold the components in position for final welding or the bumps may be spot welds to weld the lower part of the step to the channel extension. The consensus of my experts is that these are spot welds intended to weld the lower part of the step to the channel to distribute the loads over the full cross section of the step rather than the partial cross section where the failure occurred. Examining the interior of my failed step below where the step fractured you can see and feel two small bumps of discolored metal protruding from the interior surface. On the exterior of the channel that extends below the fracture (the channel was cracked but stayed with weldament part of the step) you can see a couple of small spots where the metal has been melted but without any significant penetration. These observations suggest that these areas were intended to be spot welds (2) on each side of the channel but did not penetrate the channel enough to fuse the two parts together.
I talked to Van?s Tech Support last week and was told there were no spot welds on the step. On 10/17/15 I sent Van?s 2 photos of my failed step. The exterior spot weld bumps did not show up well since the step was painted. The 2nd photo of the interior of the step clearly showed 2 rough discolored circular areas of heated and melted metal that supported the spot weld explanation. On 11/20/15, I sent Van?s a photo of the unpainted replacement step with the two exterior bumps clearly visible and asked for an explanation.
I received an answer to my 10/20/15 e-mail from Van?s today (11/23/15) confirming that the bumps on the step weldament are spot welds and are intended to penetrate into the channel. The spot welds on my failed step did not penetrate into the channel so that confirms what my experts have been telling me. Since there is no way for me to determine if the spot welds have penetrated the channel (on the new step and old passenger step) we plan to Rosetta Weld each of the 4 areas on each step weldament where the suspect spot welds are evident. This will insure that the parts are welded together and that the loads are distributed to the entire cross section of the step. The Rosetta welds may not be the final answer to the step failures but it goes a long way toward making sure that weld penetrates the channel and loads are distributed as intended.
Bob Kibby ?N712BK?
 
Quality control ?"

Bobbie
I looked at the photos you sent me.
and I think you have a good grip on the problem.
This needs van's attention soon.
I think the welding process needs more checks and testing.
So many things can affect the quality of a weldment.

This may only be a problem on some of the weldments
Quality control ?"

MY View

Joe Dallas
 
Pix available?

Bobbie. Any chance you could put those pix up here so we can compare to ours? Thanks!
 
BP_001.jpg


BP_002.jpg


BP_003.jpg



Thanks Bob

Joe Dallas





Joe,

Yes, please post the step failure photos for me.

Bob Kibby N712BK
 
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