Horizontal stabilizer complete!

The horizontal stabilizer is 100% done after only 137.1 hours of work (and re-work, and re-re-work):
Completed Horizontal Stabilizer!
The longest part of it was riveting the ribs to the skins - several rivets had to be set multiple times (they're close to tolerance, and I assume the layers of primer bring me even closer to that, so I had to up-size a few of them):
Riveting ribs to skins

Riveting ribs to skins
Another important step was to figure out where to install nutplates for bonding with the elevators (where the static wicks will live). From several posts from other builders, such as Mouser (thanks again!), I ended up deciding on using the hinge brackets themselves, and I wanted to use the most inboard brackets as that reduces the forces acting on them:
Bonding strap screw hole

Nutplate for the bonding strap screw

Once that was done and every inside rivet was checked and re-checked (and some replaced), I attached the rear spar to the ribs and then to the skin:
Rear spar ready to be riveted to the HS
While attaching the last side of skin to the rear spar, I had a small misalignment issue:
Oops, those holes don't match!

It was less than 1/32", but enough to make rivets not go in straight:
Diagonal rivets :/

I eventually fixed it (with help from VAF once again!) by slowly using a dimple die to bring the skin to alignment around a hole, then clecoing the next hole (and repeating that for every other hole in the spar).

Now, on to finish the elevators! (already about halfway done)

Time lapse:



Total horizontal stabilizer time: 137.1h
Total horizontal stabilizer rivets: 1292
Total empennage time: 311.5h
Total empennage rivets: 2101

Horizontal stabilizer riveting

I've been doing a lot of HS riveting now that all the parts are primed:

All the primed parts from last week, plus spars (priming and riveting done some time back)
I started by riveting the inboard ribs plus stringers, then attaching those to the front spar:

Stringers / most inboard ribs riveted to the front spar
Next was adding the other inspar ribs (except the outboard 2) and rivet them as well:

All inboard ribs riveted to the spar/ribs/stringers assembly
The nose ribs were riveted to the skins (a bit challenging given the little clearance for the bucking bar):

Riveting the nose ribs into the skins
The front spar assembly is then inserted into the skins:

Spar/rib assembly inserted back into the skins
It is riveted to the nose ribs using a mix of solid and pop rivets:

Pop rivets to attach the front spar to the nose ribs

Rivets attaching the inboard nose ribs to the front spar
Then the last 2 outboard ribs are added and riveted (one with pop rivets, the other with solid ones):

Outboard inspar ribs riveted
The next step is riveting the entire front spar to the skin, which was a lot of work (over 180 rivets):

Those front spar rivets behind the stringers were annoying to reach with the bucking bar

Nose ribs and front spar riveted to skin
Nose ribs and front spar riveted to the skin

There are a few rivets left to do on the left bottom skin to front spar attachment, then I'll start riveting up the inspar ribs.

Time lapse:


Total horizontal stabilizer time: 109.4h
Total horizontal stabilizer rivets: 491

Popular posts