Vertical stabilizer mounting brackets and aft fuse assembly

[N814W]

Ok, I'm getting close to popping the aft fuselage together. When fitting the belly skin, it came to my attention that the lower vertical stabilizer mounting bracket was going to need some material removed for all the pilot holes to line up - looks like radiusing the nesting corners... That got me thinking though, should I remove the upper mounting bracket from the vertical and fit it now too and rivet when I join the sides together? That would seem to make mounting the vertical a lot easier than trying to mount the vertical with the bracket still bolted to the aft vertical spar...

Thanks,
Brian

[dirkverdonck]

Hi, For all it's worth, don't yet add the bottom skin to the aft fuselage. Do this the day before your DAR is visiting for the final inspection!!!
You'll need access to the interior of the aft fuselage until all control rods and cables are installed and verified.
I have clecoed mine, updrilled and it is ready for fitting as the last job before inspection. I have also made the aft part of the lower skin removable and fitted nutplates to have better access in case I need a repair or alteration to the tailwheel attachment.
Enjoy your build, Dirk OneX 117

[N814W]

Dirk,

Thanks for the reply. I think I may not have explained my question well, but you picture helps with the illustration. I won't button up the bottom until everything else is rigged & complete (might even leave the turtle deck in clecos until then as well. My question was with respect to the vertical stabilizer mounting brackets. I built the tail kit first, and am now working the fuselage kit. The upper vertical mounting bracket that sandwiches between the L & R fuselage sides was part of the tail kit & is currently bolted to my aft spar of the vertical stabilizer. The lower mounting bracket was a part of the fuselage kit. When I started fitting everything together, it became apparent that the lower bracket was going to need some chamfering to the outside lower edges to nest into the lower longerons properly as well as needing shaved a smidge on outside edges so that the two sides would come together and match with the pre-drilled holes in the lower mounting bracket and belly skin. My head-scratcher, is whether I should unbolt the upper bracket from the vertical and start fitting it as I did the lower before I start tying the left & right sides together at the cross ties.

The other obvious question is, if I don't do it this way, how the heck do you get the upper mounting bracket/vertical into place on the already riveted fuselage per the plans construction order. The front of the bracket is way wider than the gap at the rear.

I'm pretty sure I see your upper mounting bracket and lower gear leg support plate fitted in your pic, which kinda confirms what I was wondering about. We tried an impromptu mockup of the vertical on the clecoed fuselage a couple weeks ago and I just turned around, put the vertical back in storage, and decided to worry about the fitment issues later. I haven't been able to dig up any method to this madness on anyone's build logs yet, so I'd love to hear how others have addressed the vertical install process.

Thanks again!
Brian

[A10snoopy]

Brian, here is a picture of my aft fuselage, riveted up, with the brackets inside the fuselage. The upper bracket is riveted in place. The lower bracket has been updrilled and deburred but remains "loose" until you attach the tail and lower skin.

Paul
OneX 0076

[Don_P]

Brian,

I would strongly recommend leaving the Vertical Stabilizer Upper Fuselage Attach Angle (ONX-T08) clecoed in place until after you have fitted together the horizontal stabilizer, elevator, and elevator push-rod. ONX-T08 acts as the stop for the actuator arm of the elevator horn when the elevator is in the full up position. Sonex appears to have set the actuator arm angle incorrectly, and unless modifications are made to ONX-T08 (and to the actuator arm), you may not be able to achieve full elevator up travel. Here are some photos of the modifications I made at the area around where ONX-T08 is installed. Other builders have attacked the up-elevator problem in different ways, including cutting off the actuator arm and welding it back on at the correct angle. I found that modifying ONX-T08, the aft end of the upper longerons, and the lug on the actuator arm achieved the desired result. The side notches in ONX-T08 and in the longerons were made to provide clearance for the bolt head and nut/cotter pin used to attach the elevator push-rod to the actuator arm.

To get this right, I had to remove, adjust, and replace ONX-T08 multiple times, and I did not finally rivet it in place until I could get near full up elevator travel (I came within about 3 degrees, which Sonex tech support says is OK). Note also that a substantial amount of the lug on the actuator arm had to be removed at the point where it strikes ONX-T08 (lower photos).