Y tail fittings

[Bryan Cotton]

Waiexers,
Plans show to bolt the F23-06 channel to the Y tail fittings - but then how do you deburr when you drill the channel to the fuselage?

[Rynoth]

I think I used my trusty spare 6" steel ruler to knock those burrs off. Or you can just put a skeleton crew of bolts to hold it together, drill, unbolt and deburr.

That whole tail cone area is very complicated.. it's one thing to get everything drilled out right, but you must have a detailed plan of action for you how plan to rivet it all together... very easy to rivet your way out of access to install another part, and the plans don't offer much guidance.

Something I might suggest since you already have your stabilators done is to go ahead and complete the stabilator installation prep (minus final rivets/bolts) before you get to the turtledeck. Access is easier. At least have a look at it before you move past the tailcone box assembly.

[Bryan Cotton]

Another question - the Big Y has all the holes. The little Y is missing the holes on the bottom. I assume in the original design we stopped at the little Y and transferred the holes below the bend to ensure alignment. Now we have the honking thick -016 doubler. It has all the holes. Do we just assume the Big Y holes and the honking thick -016 doubler holes line up, and punch them through the little Y?

[Rynoth]

I think you summed it up. Even the Big Y is missing a pair of pre-drilled bolt holes if I recall correctly. That stack is thick when it's put together!

The NAS bolts at the top of the stack are probably not in your hardware kit, they weren't in mine. I don't think the hardware list was updated with the service bulletin. I have the home-builders hardware kit with extra bolts and may have needed a few from that in the rest of the stack as well, since all the bolts that go through the doubler strap will be longer than they used to be.

I'm also curious how your front spar (hockey stick) attach angles line up (in the stabilator installation) once you have a fuselage box to test it on. I had to shorten the angles to clear the new bend line in the hockey stick, since you have the machined angles I wonder if they took this into account.

[Bryan Cotton]

Something I might suggest since you already have your stabilators done is to go ahead and complete the stabilator installation prep (minus final rivets/bolts) before you get to the turtledeck.

Ryan,
Did you cleco the y fitting on your tail, updrill and deburr before the Y tail was mounted?

[Rynoth]

Yes I did, my Stabilators are fully up drilled and mostly riveted (the inboard half of the piano hinges aren't riveted yet, but the rest of the skins are). I did it before I had an aft fuselage. This was a big part of my fear when my large Y fitting was recalled, but things turned out Ok.

Per the plans, it's not exactly out of order except for the fact that you're only completing half of the Stabilator installation (T07) page. The other half being the forward(hockey stick) attachment. My point in what you quoted is to at least have a look (if not mostly complete) T07 before you have a Turtledeck, since the Turtledeck makes access more difficult.

Also, and I'm sure you know this, don't rivet the bottom aft fuselage skin until the plane is done.

[Bryan Cotton]

We are bolting it up for keeps. It seems the hardware callout gives me bolts all one size too big. I need 3 washers for the NAS bolts. For the AN3's I have a lot of extra hardware from my prior collection so I could get the right size, but for the NAS stuff I ordered that special.

[Rynoth]

If I recall, I wasn't able to fasten all the bolts until the Y was in position on the aft fuselage, something about the order of assembly in that complex aft tail cone area. In other words, some parts in the stack may need to be unbolted as you assemble. There may be a way around this, I just didn't find it.

[Bryan Cotton]

Waiexers,
On the back of the tailcone box, it is tight between the channel and the doubler strap. Does it rivet up ok? It seems like I may need to start setting the rivets before the head is all the way flush, especially where the hinge is. Is there an issue here or am I just paranoid?

[Rynoth]

Bryan, I wish I'd documented this process better, but I think this might have been the reason I installed the Y-fitting piecemeal before finaly tightening all the bolts. If I recall, I left the doubler strap off, then set the rivets through the channel, then slapped the doubler on and finished installing all the bolts.

I definitely did have to bend the last 1/2" of the side skins (and the channel) outwards a few degrees for the driven rivets to clear the doubler strap. This is called for in the plans.

This area was thus far the most complicated part of the entire build for me in terms of getting creative to make it work, with little to no guidance from the plans.