Next question is how to drain the brake lines so they can be disconnected without dripping fluid inside the fuselage.
The 30 page SB 12-11-09 is now posted on Van's web site.
Step 32: Add bevels to the four corners of the U-1202 Outboard Main Gear Attach Brackets.
Has anyone done this yet, and if so, how? My first inclination is to take the grinding wheel to it, but my first inclination is almost always wrong.
Problem here is that I don't have a Plan B.
It is my understanding that the SB fix has taken the "step" issue out of the problem. It is also (IMHO) why the doublers are located on the bottom of the C-Section instead of the top of the C-Section which would have been an easier installation. I have noticed from the photos of C-Section cracks (Fig 16 of the SB for example) that all of them appear to have a "step" in the bolt hole cut-out area. I have a step at all 4 bolt hole cut-outs and have 2 cracks at the right forward bolt hole and 1 crack at the left forward bolt hole. The "step" may not be the only reason that some of us have cracks but I do believe that it is a significant contributor to our landing gear damage. Maybe a "structures guy" could comment on my speculation. I have received the SB Kit and it looks stout! Bob Kibby "N712BK"
That's what I was expecting, but I can't get my fuzzy "structures" head around how this takes the step issue out of it (home with the flu). I'll go back and have another look.
Step 32: Add bevels to the four corners of the U-1202 Outboard Main Gear Attach Brackets.
Has anyone done this yet, and if so, how? My first inclination is to take the grinding wheel to it, but my first inclination is almost always wrong.
Problem here is that I don't have a Plan B.
It is my understanding that the SB fix has taken the "step" issue out of the problem. It is also (IMHO) why the doublers are located on the bottom of the C-Section instead of the top of the C-Section which would have been an easier installation. I have noticed from the photos of C-Section cracks (Fig 16 of the SB for example) that all of them appear to have a "step" in the bolt hole cut-out area. I have a step at all 4 bolt hole cut-outs and have 2 cracks at the right forward bolt hole and 1 crack at the left forward bolt hole. The "step" may not be the only reason that some of us have cracks but I do believe that it is a significant contributor to our landing gear damage. Maybe a "structures guy" could comment on my speculation. I have received the SB Kit and it looks stout! Bob Kibby "N712BK"
It looks like F1204V fixes the step by laying flat over it
can someone who actually has the kit confirm that?
It looks like F1204V fixes the step by laying flat over it
can someone who actually has the kit confirm that?
The F-1204V is not an added part, it is a drill template used in preparation for installing the parts.
The step by step instructions explain its use on page 17.
Vans were aware of the step when they did their investigation and clearly don't consider that it needs any correction. If you try to remove it, you are more likely to create a problem. In fact, the plus side of having a step is that you have a little extra thickness in that area to distribute the bolt tension, and that's not a bad thing.
Robert
I see this in a different view
The high point narrows the point load and increases the shear potential
However van's has solved this problem by adding a bolt at each side to share the tension and move it to the flange of the U-Chanel.
Vans were aware of the step when they did their investigation and clearly don't consider that it needs any correction. If you try to remove it, you are more likely to create a problem. In fact, the plus side of having a step is that you have a little extra thickness in that area to distribute the bolt tension, and that's not a bad thing.
The bigger question for Vans is why is there variation in these hole pockets? Some have no steps, and those that have steps, have steps of varying dimensions. For a machining operation on a piece of Primary structure, this is clearly unacceptable. Very hard for me to fathom how this could happen in the first place, and also how it could pass post-machining inspection. This variability makes defining the problem and the solution that much more difficult.
And yes, I say this (reluctantly) as having been Director of Quality Assurance for 10 years at Boeing Commercial Airplanes.
I myself wouldn't touch adjusting the step with a ten foot pole.
Bob Bogash
N737G
For RV2002Builder, I have steps at all 4 outboard bolt hole locations and I have 2 cracks on the right side forward hole and 1 crack on the left side forward hole.
There was no washer contact from the bolt hole to the flat part of the C-section at any of the 4 bolt hole locations.
I plan to do SB 12-11-09 completely, when my parts arrive. I did not do the fuel tank mod, and am considering not doing it, now that we have a much more robust MLG system. Oh, I'm building it under the EAB rules.
Any thought!!
Tom
JBs completed upgrade:
John Bender completed his SB 12-11-09 MLG Upgrade and has posted a picture album in Piccasa:
http://www.vansairforce.com/community/showpost.php?p=721630&postcount=98
John,
Hope you don't mind, a post in this thread will lead searchers for SB 12-11-09 to your pictures.
Tony
to be honest, I just put it there cause it worked. It is behind the leg until it goes into the fuse. Photo may be deceiving.
John Bender
Thanks to Tony T for the new thread. I'm glad to see Van's is "comp"ing the kit. Is there a delay for shipping. I will order ASAP.
GEICO266 mentioned cherry rivets. I haven't got my kit yet. Are they cherry rivets? I really don't want to have to buy an expensive cherry rivet puller!
GEICO266 mentioned cherry rivets. I haven't got my kit yet. Are they cherry rivets? I really don't want to have to buy an expensive cherry rivet puller!
Kits are now being received by those with non-flying aircraft.