Floors and conduits

I’ve been working on the baggage area and rear seat floors, and associated systems including wiring conduits, extra inspection covers and A/C hose routing. This work has spanned a number of sections in the build manual, there are a lot of inter-dependencies and I spent weeks hopping around while seeming to make little progress.

In the end I wound up with a large pile of parts to prime, and once that happened a lot of assembly to do. I’m near the end of all the assembly work and must have made some progress here because non-flying people who look at it now recognize it as an aircraft!

Here in no particular order are some notes on some of the non standard items:

  • Added inspection covers for the steps, as is commonly done.
  • Added access covers for the antenna positions, so that I can install or uninstall the COM antennas that are mounted under the rear seats.
  • Made a lot of 3D printed parts to support conduits. Some out of Nylon, some out of ABS. These worked out great.
  • Ran the required A/C hoses to the positions in the tunnel where the connections to the A/C condenser are made.
  • Ran a bevy of electrical conduits, overkill probably but at least I’ll have plenty of capacity for wiring front <=> back.
  • Ran the static line
  • Added a small hinge piece for a POS-12 based flap position sensor
  • Added some extra nutplates for Adel clamps to support wiring through the flap torque tube area.
  • Added conduits from the flap torque tube area down to the rear of the baggage area

Overall a lot of work to get to this point. A slow build RV-10 is a big project.

One other work item – we assembled the Aerosport seats and couldn’t resist putting one in on its slides to see how it looks. Picture below.

  • f21a
    Correcting the rear seat pans so they fit properly
  • f20n
    3D printed ABS fitting for three 20mm conduits through a 2" hole
  • f20o
    Conduit pass-through goes in F-1034A spar, existing holes with no modification.
  • f21b
    Conduits running under left side rear seat
  • f21c
    3D printed conduit pass through
  • f21d
    Left side conduits
  • f21e
    Large assembly of parts ready for priming
  • f21f
    Large assembly of parts after priming
  • f21g
    Installing rear seat pans, gently spreading side panels with jack
  • f21h
    Riveting rear seat floor pans
  • f21i
    3D printed conduit supports under left baggage area
  • f21j
    3D printed conduit supports under left baggage area
  • f21k
    Riveting left baggage floor
  • f21l
    Ready to install right rear seat floor
  • f21m
    A/C hoses into tunnel
  • f21n
    Right rear seat floor in place
  • f21o
    3D printed conduit and hose supports under right baggage floor
  • f21p
    Conduits and A/C hose under right rear baggage floor
  • f21q
    Right rear baggage floor riveted down, tunnel covers in place
  • f21r
    Right baggage side cover riveted on
  • f21s
    Baggage and rear seat floor areas complete!
  • f21t
    Fitting Aerosport products seat covers
  • f21u
    Front seat looks good


Tailcone attach

The tailcone attachment is done. I wound up spending a very large amount of time preparing items that needed to be dealt with prior to attachment, including battery mount modifications, avionics shelf supports, a yaw damper servo bracket (modified Van’s RV-14 bracket), but most notably the A/C evaporator shelf, inlet air and bulkhead outlet air (into the overhead). Many hours of design for the 3D printed parts involved in the A/C system, which will be the subject of a separate post.

In the meantime, I fitted doublers for the ADS-B antenna and A/C drain pipe, and finally fixed a dent in the side of the empennage where, a long time ago, I dropped a bucking bar. I used the “packing tape and spoon” method to work the dent back in, and then drilled a #40 hole right on the peak of what was left in order to de-stress the area. I then dimpled the hole and back riveted an AD3 rivet into it. Once painted, an astute observer might notice a rivet in an odd place, but otherwise the panel is fine now.

I fay sealed the attachment skin overlap with some Sikaflex Pro. This makes for a few nerves because it means once the assemblies are slid together they really need to be riveted in one long session. We did this with no real dramas and only one drill out. At this point in a slow build project, “Rosie” and I really have our act together and riveting goes quite quickly.

With the tailcone attached, the next step is to fit and match drill various floor panels.

  • f19a
    Fitting a doubler for the ADS-B antenna
  • f19b
    Completed doubler for the ADS-B antenna
  • f19c
    Dimpling inside the tailcone
  • f19d
    Primed parts ready for the tailcone attachment
  • f19e
    Repaired dent in the tailcone skin where I had previously dropped a bucking bar.
  • f19f
    Riveting on the tailcone
  • f19g
    Tailcone riveted on
  • f19h
    Match drilling baggage floors, baggage door surround parts
  • f19i
    Match drilling floor panels


Finish empennage fairings, begin empennage attach

Another long building delay is over. I went to Osh Kosh, traveled a lot, looked after ill friends and family, and did some consulting work. Now the weather is improving I’m determined to get the project back on track.

I finally finished the empennage fairings. Spent way too much time fiddling around with the horizontal stabilizer tip fairings. That’s now all behind me, except for some fill priming. I’ll probably put a layer of glass tape across the HS tips to metal transition, just to ensure there will be no cracking in that area.

With that all done, it’s now time to attach the empennage to the fuselage. We lifted it into place, and everything fitted really well. After a match drilling session, it is now time time to take it off, debur, prime a few parts, and then attach it permanently.

  • efair1
    Drilling and countersinking empennage fairing
  • efair2
    Drilling and countersinking empennage fairing
  • efair3
    Drilling HS tip fairings
  • efair4
    Empennage fairing
  • efair5
    HS tip fairing riveted on
  • efair6
    Tapping longeron #6 for empennage gap fairing
  • efair7
    Empennage ready for attachment to fuselage
  • ejoin1
    Empennage attached to fuselage for match drilling
  • ejoin2
    Empennage attached to fuselage for match drilling

Empennage fairings [32.0 hours]

It’s time to dig out the empennage and start some preparation for attaching it to the fuselage. I have to take the tail feathers off, but before doing that it’s best to deal with the empennage fairings – can’t put off fibreglass work any longer. As supplied the fairings require some trimming, and in general fit reasonably well but far from perfect. Here’s what I did to each part:

The elevator fairings – I didn’t like the uneven gap around them, and the front side had a gap in the centre of about 2mm. I used good quality 3M electrical tape as a release agent, scuffed the sides and front of the fairing, and applied a mixture of West Systems epoxy and micro-balloons around the exterior with the fairing cleco’d in place. Once this set, I sanded off the excess micro down to the tape, removed the fairing and then removed the tape. I had to repeat this operation in a few sections. I also epoxy’d a narrow strip of 0.025″ Alclad around the interior along each rivet line. I decided to use nutplates to attached the elevator fairings, so they can be detached if I need to adjust the elevator counterweights, so I used #6 nutplates held in place with NAS1097 rivets. I dimpled the elevators with #6 die, and used countersink #6 screws to complete the assembly.

For the bottom rudder fairing, I used the same method. I also added a metal backplate into which I can screw the tail-light.

For the top rudder fairing, I added the interior Alclad strip as well, even though I riveted it to the rudder. I didn’t like the idea of the rivets cracking the fibreglass as they were set. The front side of the top rudder fairing had a significant gap, which I built up with a layer of glass and flox, and finished with micro. I continued a thin micro application right across the front surface of the rudder balance arm, since this is a permanent attachment.

For the horizontal stabilizer fairings – I trimmed them, and using a balsa-wood insert covered in packing tape, applied a layer of glass and then two internal layups. After trimming I used some micro to build the edges back up a bit for the nominal 1/8″ clearance, with a concave inner surface that the elevator counterbalance arms can swing across.

The empennage fairing – I covered the tailcone, HS and VS surfaces with packing tape, layered flox along the surfaces where the fairing rests on metal, and cleco’d the fairing in place. I did this in two parts – the horizontal sections first, then after release and cleanup, the vertical stabilizer. The flox released OK, and to clean the packing tape residue off the metal surfaces I used Eucalyptus oil followed by Acetone. I then trimmed the fairing down to the trim lines, first with a Permagrit dremel cutting wheel, and finishing off with a sanding disk in the die grinder. I also trimmed and sanded any excess flox that had run down across the interior of the fairing. The end result was a fairing which fitted tightly against all surfaces. I’m going to fill some of the screw holes, with the fairing properly fitted like this it is not necessary to have as many screws along each edge.

Now I have a lot of pinholes to fill. I plan to do these with the epoxy / squeegee method, then will apply a coat of epoxy primer followed by a fill primer to complete the surface work. Overall the fairings have been quite a bit of work, spread out over several weeks. Weather is cold at present, and even using the “fast” hardener I’ve sometimes had to leave a heater on in the workshop overnight to get proper curing of the epoxy.

  • fair1
    Using electrical tape as a release agent
  • fair2
    Large gap on front of elevator fairing
  • fair3
    Slathered on micro
  • fair4
    Same treatment for bottom rudder fairing
  • fair5
    Same treatment for top rudder fairing
  • fair6
    Large gap on front of top rudder fairing
  • fair7
    Fitting metal support for rudder tail light
  • fair8
    Right elevator fairing after sanding, left ready
  • fair9
    Elevators, rudder micro curing
  • fair10
    Bottom rudder fairing with micro curing
  • fair11
    Glue-ing in 0.025" Alclad support strips
  • fair12
    Flox and packing tape under empennage fairing
  • fair13
    Flox and packing tape under empennage fairing
  • fair14
    Gap between empennage fairing and Vertical Stab
  • fair15
    Flox on horizontal surfaces after release
  • fair16
    Flox and packing tape on Vertical Stab
  • fair17
    Trimming empennage fairing
  • fair18
    Fitting front Horizontal Stab fairings
  • fair19
    Fitting front Horizontal Stab fairings
  • fair20
    After layups, fill and sand front Horizontal Stab fairing
  • fair21
    After layups, fill and sand front Horizontal Stab fairing
  • fair22
    Nutplates and 0.025" Alclad strips on bottom rudder fairing
  • fair23
    Nutplates and 0.025" Alclad strips on bottom rudder fairing
  • fair24
    Dimpled #6 bottom of rudder, aft most holes not done yet
  • fair25
    Checking top rudder alignment
  • fair26
    Checking clearances with bottom rudder fairing in place
  • fair27
    Top front of rudder, with plenty of pinholes to fill


Forced break from building, and new toys [4.0 hours]

Due to other commitments, I’ve had to take a few months off from building, from April through June, but as of July I’m back at it again. Apart from doing the MPC course there was one notable event during this time, with the arrival of the finish kit, propeller and spinner from Van’s, the cowling from Showplanes, and the engine from Barrett Precision Engines. Finish kit inventory didn’t take long. Now I’ve really got to get on with it…

  • freight1
  • freight2
  • freight3
  • freight4
  • freight5
    Propeller crate
  • freight6
    Extra Alclad with finish kit
  • barrett1
    Barrett IO-540
  • barrett2
    Barrett IO-540
  • barrett3
    Barrett IO-540
  • prop1
    Propeller in crate
  • prop2
    Propeller blade
  • spinner1
    Hartzell spinner


Maintenance Procedures Training Course

In order to maintain an experimental aircraft, a builder has to complete the SAAA’s Maintenance Procedures Course. I attended the MPC course, held in Gawler SA, on May 20/21 and subsequently completed the take-home exam in June. If I pass the exam (80% required), I will get issued with a certificate, which gives me authority under CASA Instrument 15/16 to maintain this aircraft and issue new maintenance releases. The course was well run and it was good to get away and hang out with other people building their own aircraft.

TC visit #2 [5.0 hours]

In Australia, you need at least 3 SAAA Technical Counselor (TC) visits during construction in order to check off a box with the insurance company. In my case I have to fly a TC down from the mainland, so we did a combined visit between myself and an RV-9A builder in my local area. We all had a good day going over the two projects, it was good to spend some workshop time just chatting about the build(s). My TC is a wealth of information and we were able to spend some time at the end of the day going over the paperwork requirements for having a C of A issued in Australia.

Step installation [4.5 hours]

Step installation was straightforward. I started by thinking about whether I needed a drill guide (yes) and how to make one, then realized the easiest way by far would be to 3D print it. The design took 20 minutes and one print iteration. I made up guides for #30 and #12 drills. I also made up a 1/4″ guide but didn’t use it, when I decided to use the AN-3 bolt per the plans rather than the larger AN-4 bolt. The drill guides worked a treat.

Download the STL file here: Download

Step “wobbling” has been a common problem in RV-10’s. To combat this I installed a doubler plate to provide extra support for the step support block, and I used TCW Tech’s step bushings as well as carefully reaming the final hole in the step and support.

The only thing left now is to prime the steps.

  • f18b
    Doubler plate for Delrin step support block
  • f18c
    Step support block
  • f18a
    Step drill guide design
  • f18d
    Step drill guide after printing
  • f18l
    Drill guide in position for right step
  • f18e
    Setting the step sweep back angle
  • f18f
    Setting the step sweep back angle
  • f18g
    Setting the step sweep back angle
  • f18h
    Step drilled and bolt in place
  • f18i
    Ready to drill #30 the left step
  • f18k
    Right step fitted, ready to remove and prime
  • f18j
    Collect the full set!

Section 29 complete! [13.5 hours]

I installed the front floor pans and gear mounts, and have now finally completed the infamous and tediously long  Section 29 of the RV-10 manual. It was a relief to have both gear mounts bolt in without any drama, there have been some horror stories about this step in the plans. The tapered shims I made up for the gear mounts worked a treat and I all bolts were snug in their holes with no need to ream anything.

The empennage has been shoved in a back corner for the past year. I wanted to work out a few things prior to attaching the tailcone to the fuselage, so I swapped the empennage and spray booth around. There isn’t much priming left to do, so the spray booth (which is on wheels) can stay in the corner for the time being, before I retire it completely. This move has opened up the workshop a bit.

Next item is to install the steps.

  • f17a
    Installing left floor pan
  • f17b
    Installing left floor pan
  • f17c
    Both floor pans installed
  • f17d
    Both gear mounts installed
  • f17e
    Empennage moved out of the back corner
  • f17f
    Spray booth shoved in the back corner