Door and latch hole drilling

I got back to working on the doors, starting with trimming the handle levers a bit more for a better fit, priming, painting, then assembling the handles:

Door handle parts attached together

I then started match-drilling the fuselage and the doors (at least in parts where I hadn't sanded it down beyond the holes - oops):

Door match-drilled to fuselage

Hole where i had trimmed the door too far to match-drill

Door clamped firmly in place for match-drilling the window frame

Window frame match-drilled between door shells

I also finally (after about 4 months) received the Aerosport low-profile handle, so it was time to start thinking of the latch mechanism - starting with drilling the holes for it. I wanted to avoid actually drilling through the door towards the exterior until the halves are joined, so I "aimed" the best I could using the backing plate and other parts, and opened those holes - expanding them later should be easy if needed:

Aligning latch rack for drilling holes

Aligning latch racks for drilling holes

Latch rack holes drilled into inner door shell

Trying out mounting the door latch racks/gear to adjust gaps around racks

I also opened up the slots for the center latch. I had originally planned to install it through just a single hole for the axis, but decided it was not worth the complication (I could end up with epoxy in the gears, might someday need to remove them, would have trouble with the screws being too close to edges, etc.), so I opened up the slots per instructions:

Match-drilling center latch holes to door inner shell

Center latch attached in place

Next I want to finish getting the latch mechanism ready (as much as I can before the door halves are joined), and then join them.

Time lapse:


Total cabin door rivets: 20
Total cabin door time: 39.9h

Empennage fairing riveting and filling/sanding

I continued the work on the empennage fairing by drilling the nutplate holes for its screws:

Vertical and horizontal stabilizer nutplate holes

Vertical and horizontal stabilizer nutplate holes

Unfortunately, most of those holes actually were on or very close to the flange flutes. I was afraid that a solid rivet would expand in that space, and didn't want to flatten the flute, so instead of dimpling and riveting with solid rivets, I machine-countersunk and used CCR264 nutplate blind rivets, which worked out well:

Vertical stabilizer nutplate holes overlapping the flutes

Vertical stabilizer nutplates attached with CCR264s

Vertical stabilizer fairing nutplate holes attached

On the horizontal stabilizer, I did dimple and use solid rivets (except for two holes which were too close to the edges of the rib flanges, so I countersunk those):

Horizontal stabilizer fairing nutplates attached

We continued the sand-fill-repeat process on the bottom rudder fairing, and got a lot closer to a good finish:

Bottom rudder fairing with primer applied to spot pinholes

At this point, we, of course, sanded it again as several pinholes became evident - and squeegeed another layer of resin with some flox in:

Bottom rudder fairing trailing edge after another layer of resin

We laid up some epoxy and flox around the elevator fairings to make a smooth transition:

Forward face of the elevator fairing filled with resin/flox (unsanded)

Gap between fairing and elevator filled with resin/flox (unsanded)

After that comes a lot of sanding to make a smooth transition on all of them. So far we only did the forward faces, and even those still need a lot of pinhole filling:

Forward face of left elevator fairing, before filling pinholes

Forward face of right elevator fairing, before filling pinholes

Time lapse:


Total empennage fairing rivets: 44 
Total empennage fairing time: 49.5h

Door riveting and sanding

We final-attached the gas strut attach doublers in place, with both epoxy and rivets:

Applying epoxy (with cab-o-sil) to gas strut attach doublers

Epoxying the gas strut attach doublers in place

Gas strut attach doubler rivets

We then sanded all the door shell inner contact surfaces (where the two shell halves touch), as well as the cabin cover flange to let the doors sit flush. In one place, we sanded too much and had to fix it with more fiber:

Door shell corner where we sanded too much

Laying up fiber where we sanded too much

Fiber laid up where we sanded too much

Next is, of course, more sanding :) and getting the doors shell halves drilled together in place.

Time lapse:


Total cabin door rivets: 20
Total cabin door time: 29.4h