When to rivet lower fwd fuselage skin?

[NWade]

Hi All,

So I am finally closing in on completing the basic airframe! Wings & Empennage were done a long time ago, and the Fuselage has been the main project for the majority of this year.

I'm working on the SNX-F09 and F08 pages, and I'm wondering when I should rivet in the lower forward fuselage skin. Conventional wisdom says to wait as long as possible. But with all of the F10 parts that tie into the lower fuselage skin (between the spar tunnel and the aft spar carrythrough), it seems like it should all go together at once, no? The aft bottom skin can still be left off until much latter (to make rigging controls easier), but it seems like the forward skin should go on now.

Any tips or thoughts on the ideal time to do this?
(Other tips or suggestions on finishing out the fuselage are always appreciated as well)

Thanks, take care,

--Noel
Sonex #1339
Center-stick, Taildragger, Acro-Ailerons, Flush (pulled) rivets, Aerovee Turbo

[Bryan Cotton]

Noel,
I had the same mindset as you. Steve from down under talked me out of it and I am glad. I think I will rivet mine after first flight. Much easier to work under there kneeling on the floor of the hangar.

[kmacht]

Not until the very last minute before the dar inspection. Having it open will allow you to easily get behind the panel to fix wiring, pull the gas tank if needed, adjust the rudder cables, etc. The moment you rivet it on you will instantly find a reason to wish it were still remove able. I have been finished with my plane a few years and still wish mine could be pulled at times.

Keith
#554

[wlarson861]

Not until the very last minute before the dar inspection. Having it open will allow you to easily get behind the panel to fix wiring, pull the gas tank if needed, adjust the rudder cables, etc. The moment you rivet it on you will instantly find a reason to wish it were still remove able. I have been finished with my plane a few years and still wish mine could be pulled at times.

Keith
#554

I agree. I riveted the forward floor on and left the tail belly skin off. There were several times i had to crawl under the panel while finishing everything. Just make sure the floor is clecoed well when rigging the wing to keep everything rigid.

[wlarson861]

Not until the very last minute before the dar inspection. Having it open will allow you to easily get behind the panel to fix wiring, pull the gas tank if needed, adjust the rudder cables, etc. The moment you rivet it on you will instantly find a reason to wish it were still remove able. I have been finished with my plane a few years and still wish mine could be pulled at times.

Keith
#554

I agree. I riveted the forward floor on and left the tail belly skin off. There were several times i had to crawl under the panel while finishing everything. Just make sure the floor is clecoed well when rigging the wing to keep everything rigid.

[Area 51%]

Like a good little soldier, I riveted mine according to the plans schedule. I didn't join this group till it was too late. I can already see the advantages of a removable floor.


What's going to save me, however, is I have a 3'9" wife that has an extra elbow and wrist on each arm, and I still have a hang-glider harness and plan to suspend myself from the ceiling when it comes time to rig the wings.

[mike.smith]

I riveted mine on the day before it's DAR inspection. I had it on with clecos any time I needed the skin on, but no riveting until the night before. Glad I did it that way. Highly recommended !!!!!!

http://www.mykitlog.com/users/display_l ... 0851&row=2
http://www.mykitlog.com/users/display_l ... 0899&row=1

[rizzz]

..., and I still have a hang-glider harness and plan to suspend myself from the ceiling when it comes time to rig the wings.

Make sure you take some pictures of that when the time comes :-)

[NWade]

So all you guys who waited until your DAR inspection: You rigged the wings with all of the F10 & F09 parts (all the bits aft of the spar tunnel) just cleco'ed in place? You can't rivet in the tunnel until you rig the wings, and those F10 & F09 parts all connect to either the spar tunnel or the lower rear horizontal cross-member. They can't really be riveted into a stable configuration without the bottom skin in, right? As strong as a well-cleco'ed bunch of parts seem, I think things can still wiggle into a different alignment when you put weight or torque on a series of cleco'ed parts... Did you essentially stop fuselage work at F09 and work on the canopy, fuel, electrical, and engine pages; then return to finish off the lower fwd fuse afterwards?

Thanks,

--Noel

[peter anson]

All the advice is good. Wish I had known about it when I built my Sonex. Even well after the aircraft is flying good access in the forward fuselage would be nice. Here's how Brian Ham achieved that; a removable floor panel which you can see in this photograph of VH-ULB (which Brian tells me stands for "you little beauty").

It does add some weight because you need to add a reinforcing ring around the hole. I think the main reason Brian fitted the panel was for access to the toe brakes he has also fitted.

Peter
Sonex 894