Center/forward fuselage questions

I've gone step-by-step with the insructions and paid close attention to the drawings. I just finished putting the ribs in the baggage area and attaching the F-750 aft baggage side covers.

According to the instructions, the next step is riveting the forward side skins and then rolling over the canoe

Here are my questions.

1. I still have not drilled the most forward two spanwise row of rivets on the bottom skin, where one attaches to the firewall. The only holes drilled there are the two on either side that we were first told to drill when fitting the firewall, and the holes at the most forward ends of the floor stiffeners. Can I go ahead and drill the rest out now?

2. Outboard rib in the center fuselage has still not been drilled to the side skins. Can I go ahead and drill that now? And when I can I rivet the aft end to the 706 bulkhead assembly?

3. Is there any reason that I should use nutplates instead of blind rivets for those floor panels that call for LP-4 blind rivets? Is there any reason not to?

4. The instructions say to rivet the F-770 side skins. And then it says "finish riveting the F-772 skins. But the bottom skin forward (F772) fits inside the side skins. So why would they say to rivet the side skins and then the bottom skin?

5. Shortly before rolling over the canoe, it says to "complete any riveting on the aft fuselage that has not been finished yet." Well, what's not finished on mine are the rivets north of the skin stiffeners it said not to rivet because the longerons have to fit in.

I assume, then, that this is the point at which I can deburr and prime the longerons, right?

I think that's it unless you know of a "gotcha" sitting out there at this point waiting for me.

Thanks.
I assume before I start riveting here, the longeron

I'll take a stab at your question, only because noone else has. It's been a while since I was at the center/fwd fuselage stage, and my memory's already a little fuzzy. So don't take my answers as gospel.

The instructions/plans aren't very clear on the exact order for things at this stage. Where you're at, it's basically time to drill everything that needs to be drilled and prep it for assembly.

1. I still have not drilled the most forward two spanwise row of rivets on the bottom skin, where one attaches to the firewall. The only holes drilled there are the two on either side that we were first told to drill when fitting the firewall, and the holes at the most forward ends of the floor stiffeners. Can I go ahead and drill the rest out now?

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Should be fine. I drilled mine around the point that you're at. I then dimpled the bottom skin and countersunk the firewall angle.

2. Outboard rib in the center fuselage has still not been drilled to the side skins. Can I go ahead and drill that now?

Click to expand...

I assume you're talking about the outboard seat ribs. Yup, that's really not mentioned anywhere. Now's a good time to drill them.

And when I can I rivet the aft end to the 706 bulkhead assembly?

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These are seat ribs, right? The aft end would attach to the F-705. Now is fine.

3. Is there any reason that I should use nutplates instead of blind rivets for those floor panels that call for LP-4 blind rivets? Is there any reason not to?

Click to expand...

The only reasons I've read are for inspection purposes or to make running wiring easier. Installing all of those nutplates is a hassle. I'm planning on putting in conduit and probably two access panels so I can mount the strobe power supply under the floor and inspect the nuts on the back of the seat belt anchors.

4. The instructions say to rivet the F-770 side skins. And then it says "finish riveting the F-772 skins. But the bottom skin forward (F772) fits inside the side skins. So why would they say to rivet the side skins and then the bottom skin?

Click to expand...

I think the assumption is that you'll have the side and bottom skins clecoed on, rivet the sides, then the bottom. I left off the bottom skin until the last minute for better access, which ended up being a little difficult. I riveted too far down on the side skins making it difficult to slip the bottom skin underneath it.

5. Shortly before rolling over the canoe, it says to "complete any riveting on the aft fuselage that has not been finished yet." Well, what's not finished on mine are the rivets north of the skin stiffeners it said not to rivet because the longerons have to fit in.

I assume, then, that this is the point at which I can deburr and prime the longerons, right?

Click to expand...

Yup. You'll then rivet up to the longeron and then rivet only the keeper rivets on the longerons plus where ever you don't have overlapping top skins. That last part isn't mentioned in the instructions. You'll have to look very carefully at the drawing with the skin rivet call-outs (be sure to look at the right figure, slider vs. tip-up) and determine where the top skins overlap.

Getting that fuselage riveted together is a nice feeling. Just take it one part at a time, and try to think 5 steps ahead. I made a list of what I wanted to rivet in what order. It wasn't really that necessary, but provided some peace of mind. I'll look this weekend to see if I still have it.

Dave