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
    f19a
    Fitting a doubler for the ADS-B antenna
  • f19b
    f19b
    Completed doubler for the ADS-B antenna
  • f19c
    f19c
    Dimpling inside the tailcone
  • f19d
    f19d
    Primed parts ready for the tailcone attachment
  • f19e
    f19e
    Repaired dent in the tailcone skin where I had previously dropped a bucking bar.
  • f19f
    f19f
    Riveting on the tailcone
  • f19g
    f19g
    Tailcone riveted on
  • f19h
    f19h
    Match drilling baggage floors, baggage door surround parts
  • f19i
    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
    efair1
    Drilling and countersinking empennage fairing
  • efair2
    efair2
    Drilling and countersinking empennage fairing
  • efair3
    efair3
    Drilling HS tip fairings
  • efair4
    efair4
    Empennage fairing
  • efair5
    efair5
    HS tip fairing riveted on
  • efair6
    efair6
    Tapping longeron #6 for empennage gap fairing
  • efair7
    efair7
    Empennage ready for attachment to fuselage
  • ejoin1
    ejoin1
    Empennage attached to fuselage for match drilling
  • ejoin2
    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
    fair1
    Using electrical tape as a release agent
  • fair2
    fair2
    Large gap on front of elevator fairing
  • fair3
    fair3
    Slathered on micro
  • fair4
    fair4
    Same treatment for bottom rudder fairing
  • fair5
    fair5
    Same treatment for top rudder fairing
  • fair6
    fair6
    Large gap on front of top rudder fairing
  • fair7
    fair7
    Fitting metal support for rudder tail light
  • fair8
    fair8
    Right elevator fairing after sanding, left ready
  • fair9
    fair9
    Elevators, rudder micro curing
  • fair10
    fair10
    Bottom rudder fairing with micro curing
  • fair11
    fair11
    Glue-ing in 0.025" Alclad support strips
  • fair12
    fair12
    Flox and packing tape under empennage fairing
  • fair13
    fair13
    Flox and packing tape under empennage fairing
  • fair14
    fair14
    Gap between empennage fairing and Vertical Stab
  • fair15
    fair15
    Flox on horizontal surfaces after release
  • fair16
    fair16
    Flox and packing tape on Vertical Stab
  • fair17
    fair17
    Trimming empennage fairing
  • fair18
    fair18
    Fitting front Horizontal Stab fairings
  • fair19
    fair19
    Fitting front Horizontal Stab fairings
  • fair20
    fair20
    After layups, fill and sand front Horizontal Stab fairing
  • fair21
    fair21
    After layups, fill and sand front Horizontal Stab fairing
  • fair22
    fair22
    Nutplates and 0.025" Alclad strips on bottom rudder fairing
  • fair23
    fair23
    Nutplates and 0.025" Alclad strips on bottom rudder fairing
  • fair24
    fair24
    Dimpled #6 bottom of rudder, aft most holes not done yet
  • fair25
    fair25
    Checking top rudder alignment
  • fair26
    fair26
    Checking clearances with bottom rudder fairing in place
  • fair27
    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
    freight1
    Finally!!!
  • freight2
    freight2
    Unloading...
  • freight3
    freight3
    Unloading...
  • freight4
    freight4
    Unloading...
  • freight5
    freight5
    Propeller crate
  • freight6
    freight6
    Extra Alclad with finish kit
  • barrett1
    barrett1
    Barrett IO-540
  • barrett2
    barrett2
    Barrett IO-540
  • barrett3
    barrett3
    Barrett IO-540
  • prop1
    prop1
    Propeller in crate
  • prop2
    prop2
    Propeller blade
  • spinner1
    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
    f18b
    Doubler plate for Delrin step support block
  • f18c
    f18c
    Step support block
  • f18a
    f18a
    Step drill guide design
  • f18d
    f18d
    Step drill guide after printing
  • f18l
    f18l
    Drill guide in position for right step
  • f18e
    f18e
    Setting the step sweep back angle
  • f18f
    f18f
    Setting the step sweep back angle
  • f18g
    f18g
    Setting the step sweep back angle
  • f18h
    f18h
    Step drilled and bolt in place
  • f18i
    f18i
    Ready to drill #30 the left step
  • f18k
    f18k
    Right step fitted, ready to remove and prime
  • f18j
    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
    f17a
    Installing left floor pan
  • f17b
    f17b
    Installing left floor pan
  • f17c
    f17c
    Both floor pans installed
  • f17d
    f17d
    Both gear mounts installed
  • f17e
    f17e
    Empennage moved out of the back corner
  • f17f
    f17f
    Spray booth shoved in the back corner

 

Fuse side skins [55.0 hours]

Over the past few weeks, with some periods of non-work, I’ve de-burred, dimpled, primed and riveted on the fuselage side skins. With the exception of a few rivets I need to make up a special bucking bar for, the fuselage side skin riveting is now complete. Almost all of the riveting was a two-person operation, and “Rosie” did her usual terrific job on the rivet gun. I got well and truly tired of lying inside the fuselage twisting into all sorts of odd shapes in order to buck rivets.

I almost made a big mistake. I was all set to start riveting the right rear fuse skin, when at the last minute I noticed some holes that were not dimpled. This after having checked all the dimpling on at least three separate occasions before priming. I don’t know how I missed them, and I was lucky to notice the problem because there is no way I could have dimpled them in-place cleanly. It was a simple matter to take the skin off, dimple the offending holes, and cleco it back on.

I used a new, full sized, spray gun to prime the skins, which made me wonder why I didn’t get one sooner. Hard to believe I primed the wing skins with a mini-gun.

Side note – my son made me a replacement stainless steel shaft for the rudder pedals, after we found one of the four supplied with the kit was faulty. The new shaft fitted perfectly, so now I have rudder pedals ready to install.

  • f16a
    f16a
    Cutting out the baggage door
  • f16b
    f16b
    Cleaning up the baggage door opening
  • f16c
    f16c
    Right fuse skins, upper fuse skin, ready for priming
  • f16d
    f16d
    First use of new spray gun
  • f16e
    f16e
    Right and upper fuse skins after priming
  • f16f
    f16f
    Left fuse skins after priming
  • f16g
    f16g
    Back riveting F-1023 angle to right skin
  • f16h
    f16h
    Missing dimples - picked up just in time!
  • f16i
    f16i
    Riveted side vent
  • f16j
    f16j
    Fuse skins cleco'd in place, ready for riveting
  • f16k
    f16k
    First few rivets set, the start of fuse riveting marathon
  • f16l
    f16l
    Right rear fuse skin riveting done
  • f16m
    f16m
    Left rear fuse skin riveting done
  • f16n
    f16n
    Right fuse skins riveting (almost) complete
  • f16o
    f16o
    Left fuse skins riveting (almost) complete
  • f16p
    f16p
    Replacement rudder pedal part in place