Page 21-05 - Mid Fuse Seat Rib Question

Hello everyone! Please forgive that my first time posting on the board is a call for help. I am one of the lead mentors for a RV-12 build project at 45G, which is Brighton Airport in Brighton, Michigan.

My son (Collin, 13) an I have been assigned section 21, and have been working on deburring parts for the past 3-4 weeks (we meet twice per week). We finally started assembly of section 21 today and have come across what I consider to be a pretty major question, which involves the instructions on page 21-05. I apologize profusely in advance if I'm making this more complicated than it is, but I would like clarification that I'm doing the right thing, so we don't have to drill out a bunch of rivets later.

STEP 1 states:


There are four (4) total ?pairs? of seat ribs; one left and one right in each pair. I interpret this instruction to mean the one pair that the Seat Belt Attach Lug Support were previously installed, because of "Figure 1", and one pair that has yet to be touched.

I also believe that SETPS 2-4 are to be completed on these two (2) pair of seat ribs.


SETP 5 then states:


This step involves two (2) pair of seat ribs and instructs to drill the #19 holes four (4) places in each rib. These four (4) places are in the nutplate locations that are on the forward angled portions of the ribs.

Then, STEP 6 states:


Meaning, one pair from step 5 does NOT get the nutplates installed in the four (4) locations act are on the forward angled portion of the seat ribs. STEP 6 instructs to only install the nutplates in the four (4) locations on the forward angled portion of one (1) of the two (2) pair of seat ribs.

After STEP 6 I believe the following should be present:
*One left and one right seat rib with the seat belt attach lug supports riveted, #19 holes drilled nine (9) places, four (4) nutplates (K1000-08) riveted on the forward angled portion of the seat rib on each, three (3) #30 holes dimpled on each, and one #40 hole dimpled on each for the MS21051-L08 nutplates.
*One left and one right seat rib that are the same as above, but WITHOUT the seat belt attach lugs supports
*One left and one right seat rib with #19 hole drilled four (4) places, WITHOUT the nutplates installed four (4) places on the forward angled surface of the seat rib, and WITHOUT #30 holes dimpled three (3) places
*One left and one right seat rib with #19 hole drilled four (4) places, WITH the nutplates (K1000-08) installed four (4) places on the forward angled surface of the seat rib, and WITHOUT #30 holes dimpled three (3) places

If all of that is true, then I believe that this note in Figure 3:


...for STEP 10...


...is calling for the pair of ribs with #19 hole drilled four (4) places, WITHOUT the nutplates installed four (4) places on the forward angled surface of the seat rib, and WITHOUT #30 holes dimpled three (3) places. Yes...no?

Please tell me that my explanation and question makes sense to someone. LOL!

Thanks for the help, guys.

See picture below:
Ribs numbered from left to right;
1) no nutplates
2) nutplates in angled slope (21-05 step 6)
3) 9 nutplates. Initially only 4 in the angled slope (21-05 step3 / 21-07 / 21-08)
4) 9 nutplates. Initially only 4 in the angled slope (21-05 step3 / 21-07 / 21-08)
5) nutplates in angled slope (21-05 step 6)
6) no nutplates

Rib 1&6 get the nut plates at page 21-13 step 7.
Ribs 3&4 get the remaining nut plates at page 21-07 / 21-08.
(click on the picture for more pictures of chapter 21)

I like your red anodized flaperon mixer arms

I found you another picture of the red flaperon mixer arms ;-)

I like your calendar much better than the pretty mixer arms!

Thanks a ton for the information. If you don't mind, I would like to post a picture of my assembly tomorrow night, or Tuesday, just to go over it as clecoed.

Again, I really appreciate the reply.

You're welcome. For me it's almost six years ago that I was building that part. I still read the VAF forums every morning at breakfast. Questions like yours are a nice "refresher".

Have fun building!

Joeri.

Each, Joeri! Where can I get the calendar!

Rich

Sorry Rich the calendar is sold out ;-)

The calendar is old, it's from 2012. It was a "United Stripes (Dutch) Cabin Crew Charity Calendar"

Doesn't look old...