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Changing 7a to 7

jy757

Member
Converting 7a to 7

Guy has a 7a quick build fuselage with main gear mounts installed. Can this fuselage be converted to a -7 without any big issues, like holes to cover up etc?

The fuselage is still in project stage, wings not installed.
 
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There are more than a few threads here on VAF discussing this process. I converted my slow build RV-7A to a 7 as I was riveting the fuselage together. I had to remove the F-712 bulkhead (the last one) and I ordered the parts to fabricate a new bulkhead. The tie down mount interfered with the tail wheel mount.

If it is on its wheels, or at least has the gear weldment installed, your friend probably has two holes in the bottom skin. Those holes are not there on a 7 so there are two choices, drill out all those rivets or patch the two holes. They are on the bottom of the aircraft, so no one will see the patch.

If you talk Vans they can tell you the parts you need to order and they may give you credit for the 7A parts you won't use. It takes a little bit of time, but is relatively easy.
 
One of the key differences is the VS spar (edit: see below, actually the HS attach bars, not the VS). If it has been lightened by the original builder for an A model, you will have to replace it to go to TW. On a quickbuild, I believe none of the spars have been lightened, but you should cross-check with the plans to be certain. Otherwise, pretty straightforward to make the conversion - as noted, there are several threads here on VAF about doing so.
 
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VS Spar Lightening Holes

Greg Arehart, "One of the key differences is the VS spar. If it has been lightened by the original builder for an A model, you will have to replace it to go to TW."

Are you talking about the VS rear spar doubler, VS-808PP? Drawing 6 (dated 4/09/01), that applies to RV-7,8,9, shows the lightening holes as "optional" and not excluded for TW.

Hoping I didn't miss something.

Merrill
 
That's the way I remember it, as well, though it's been a really long time since I kicked myself for forgetting to cut them.
 
My mistake (excuse: it has been 8 years since I did this). It is actually the F711C, horizontal stab attach bars, Drawing 21. These can be tapered for the 9A to save a few ounces, but should be full-width for the 9 to support the tailwheel assembly. I believe that the quickbuild fuselages all come with the full width version (mine did).

Hope this saves someone from tearing their hair out over the VS. Apologies for misremembering.

Greg
 
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