View source for SECTION 26: MID FUSE RIBS & BOTTOM SKINS

=== Supplemental Instructions ===
Planes with the old flap motor (without an integrated position sensor) can be upgraded to use the new flap motor with integrated position sensor. OP 64 is the manual for how to do the upgrade.
* 09/05/22 [https://www.vansaircraft.com/service-information-and-revisions/op-64/ OP-64 FLAP MOTOR RETROFIT]
Check for more recent updates [https://www.vansaircraft.com/service-information-and-revisions/?aircraft=rv-10&doctype=revisions-changes&sort=date here]

=== Build Instruction Updates ===
* 11/05/22 [https://www.vansaircraft.com/wp-content/uploads/2022/03/26_10.pdf 26_10.pdf]
* 10/05/21 [https://www.vansaircraft.com/wp-content/uploads/2021/10/26_10.pdf 26_10.pdf]
Check for more recent updates [https://www.vansaircraft.com/service-information-and-revisions/?aircraft=rv-10&doctype=revisions-changes&sort=date here]
=== Discussions ===
* [https://vansairforce.net/community/showthread.php?t=217809 VAF thread on chapter 26 errors]
=== Notes ===

====PAGE 26-2 ====
* New Flap Motor Variant
The forward edges of the F-1066C-2-L and F-1066C-2-R reinforcement angles are not flush with the forward edge of the seatbelt attach bar horizontal extension, rather they hang over a bit. They would sit flush if left and right angles were switched, however the plans say otherwise.
* Unless otherwise specified by Vans, all rivets should have their machine heads to the inside of the foot well.  That is, the machine heads should be on the F-814HPP side.  This will aid the installation of the floor pan on page 35-2.

====PAGE 26-3 ====
Unless otherwise specified by Vans, all rivets should have their machine heads to the inside of the foot well.  That is, the machine heads should be on the F-814HPP side. This will aid the installation of the floor pan on page 35-2.

If you have part F-1016D (seatbelt strap) with an extra tab on the side and two additional holes but your manual depicts that part without flanges/extra holes, you are experiencing the transition from the old flap motor to the new flap motor where the tab is no longer needed. Your manual is a new version but Vans sent you the older part with the tab. According to Vans, just remove the tab and match drill the two extra holes and use same rivets as the other surrounding holes. For details, see this FB thread [https://www.facebook.com/groups/vansrv10/posts/4880956025358791/ (FB Link 3/28/2022]) and [https://www.facebook.com/groups/vansrv10/posts/4891736740947386/ (FB Link 4/1/2022])<br>'''If your plans don't match what you have, check the electronic version of the plans which should show up under your name in the vans store.

Step 6 gotcha (Step 7 on V2 of 7/16/21 of the page): Plans call for 'Dimple the screw holes in the inboard flange of the seat rib intercostals that correspond to the flush nut plates...' Note that there are 3 nut plates on this flange, but only 2 of them are flush nut plates. The top nut plate is a K1000-08 and must not have its screw hole dimpled.

[[File:26-3gotcha.png|426x426px]]

====PAGE 26-4 ====
There are plans provided as Rev 0, dated 7/24/14, that accidentally show the seat belt fitting on the wrong side of the left outboard rib. A correct page 26-4, also marked Rev 0 and with same date was on the thumb drive of some builders. The newest version provided on their website, marked as Rev 1 dated 2/24/22 shows it also on the wrong side. However, the detailed figure on page 26-2 shows it correctly.

====PAGE 26-5 ====
Unless otherwise specified by Vans, all rivets should have their machine heads to the inside of the foot well. That is, the shop heads should be on the F-1017A rib side. This will aid the installation of the floor pan on page 35-2.

Step 5: it doesn't explicitly say anything about fluting the F-1018-L and F-1018-R ribs. Even if it did, I might have assumed if it was straight it was good. Well, it turns out that it needs to not be straight to match the holes in the bottom skin. It is a real pain to try to flute it later.

Step 10: When riveting the F-1015A-L and F-1015A-R outboard seat ribs to the rear spar bulkhead, make sure that the forward edge nests inside the F-1004D-L and F-1004D-R bulkheads. You can see this on page 26-1 but it isn't shown or called out on page 26-5.

If you haven't updated your plans in a while, ensure you dimple the #40 holes in the web of F-1015A-L/R.  There was a revision on page 26-5 in July of 2021 that added this as step 1. However, don't dimple the holes that are on the flange of F-1015A-L/R which interfaces with F-1004D-L/R.

Note that the F-1015A-R/L seat ribs have a joggle joint on the front edge with the F-1004D-L/R bulkhead where the rib will be on the inside of the outer flange of the bulkhead. Similarly, the upper portion of the front edge of the F-1018-R/L rib goes inside of the F-1005C-L/R bulkhead however, its lower part goes outside of F-1005C-L/R.

Consider at this point whether you need access holes in the F-1017 under-seat ribs for conduit and/or antenna wiring. Many builders cut holes in the F-1017 ribs for conduit passthroughs.  These holes will be much easier to cut at this point.

Also consider marking and cutting/installing antenna doublers on the bottom skins in this general section.  This will be much easier now than later, when the seat plates are permanently riveted in place.

====PAGE 26-6 ====
This is when I realized that I had the brackets swapped on my fuselage bulkhead assembly created at the end of Section 25. Make sure the vertical bulkhead components are more or less perpendicular to the bottom bulkhead and not leaning outward. Now is the time to fix this if it is incorrect.

Double-check that the left and right WD-1008-L / WD-1008-R step weldment parts are labeled correctly by Vans. There are two reports of them being swapped.
See also [https://www.facebook.com/groups/vansrv10/posts/4902491573205236 FB Post 4/6/2022].

WD-1008-L / WD-1008-R step weldments have 16 holes each. The corresponding F-1021-L / F-1021-R outboard baggage ribs are missing four of these holes, with no instructions on the page to match drill. Vans support confirmed (12/15/2022 - Gary Keyser support engineer) that it is acceptable to match drill through the WD-1008 into the F-1021 and rivet. The plans corroborate this as they call out 32x AN470AD4-4 rivets.

Step 9 refers to "keeper rivets" which I thought meant temporary rivets, but that's not correct. You put the AN426AD3-4 rivets into the two places per side like any normal rivet. You do NOT put anything in the other five rivet holes on each side as part of this flange. Later (Section 29), the skin will rivet into those other five holes, and the keeper rivets will remain where they are, hidden underneath the skin. The keeper rivets keep everything together until the skin can be properly riveted later.

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