Since I plan to fly outside the US and in areas where TIS-B is not available, I got a GTS800 active traffic system for "cheap" on eBay (as in, 75% less than a new one). It was advertised as new but missing papers (A&Ps, please keep losing those papers!), so I wanted to verify that it was working and that it was indeed new.
The unit has two 78-pin high-density connectors and one 37-pin connector (plus the 8 connections for bottom/top antennas):
GTS800 connectors
Checking the pinout in the installation manual, it seemed I only needed to connect a few pins in the 37-pin conector for power, plus a few pins in one of the 78-pin connectors for USB to the computer. I got breakout boards for that (this, this and this):
Power and "remote power on" connections on 37-pin breakout board
USB breakout connected to the 78-pin breakout board
then connected it all:
Break-out boards plugged to GTS for testing
I had to get a special A-to-A USB cable, after a "duh" moment when I realized the USB breakout card I got had the same connector as the computer - I should instead have gotten this one. Luckily I had that cable.
My first attempt was frustrated - it just didn't turn on or get recognized by the computer, and the power supply was making a weird noise - turns out I was trying to use a 2A power supply, and it requires more than that (manual says 2.6A, I saw 2.1A after it starts up). Tried a different power supply, and it just worked!
GTS plugged to a proper power supply (the bottom one had a 2A current limitation)
The software showed me exactly what I wanted to see - that it had been turned on for only about 5 minutes, and it had recent firmware versions (so it was indeed new):
The software detects it!
Recent firmware versions
At first I was also worried that the fans didn't turn on, but as soon as the temperature reached about 35˚C, they turned on and the temperature stabilized.
With this, the GTS can go back to the shelf and wait until it's time to actually install it - at that point, I'll need to figure out its ground plane - probably following the recommendations from this VAF post as well as this blog post - not trivial, but doable.
Special thanks to VAF user Strasnuts for the help!
Progress has been slow due to a number of other events (such as studying for my CPL-AMEL checkride), but we finally finished riveting the bottom part of the tailcone! Next step is to attach the aft deck:
No clecos on the bottom part anymore! :)
The only exception is the avionics shelves in the front - I left those holes open to make it easier to crawl inside the cone. I'll rivet them after the top skin is on.
As I prepared to rivet the longerons below the aft deck, it became apparent that the F-1011 bulkhead was rubbing against it, and that could cause damage and fracture later:
Bulkhead rubbing against longeron
As much as I hate filing and removing primer with that, the solution was to file it down so they don't touch:
Bulkhead filed clear of longeron
Not much more details to share - it was mostly repetitive riveting work.
Time lapse:
Total tailcone time: 192.9h Total tailcone rivets: 1438
While waiting for tailcone mod parts to arrive or for weather to prime it, I started the few items of section 11 - "Empennage Attach" - which can be done without having completed the tailcone. Also, given that some parts used in this section are only included in the fuselage kit, and given that I don't have room in the garage to keep the fully assembled empennage (and still work on a fuselage and wings) it'll be a long time until I really complete the section.
I fabricated the F-1098 shims:
Shims marked for cutting
I put together the trim mount bracket, and to keep the brackets aligned, I used reference lines before drilling them:
Trim brackets aligned for drilling
I then primed and riveted it all together:
Trim bracket and bellcrank riveted
I put together the trim servo link/spacer assembly:
Servo with link assembly
and then attached it to the bracket:
Trim mounted in its bracket, with the linkage and bellcrank attached
If you notice the two holes on the side of the trim bracket, that's for hanging an aluminum plate with a connector. My intention is to make a single connector for the servo (5 pins) plus the ELT (12 pins if I get the Kannad), but I haven't picked the proper connector yet.
Time lapse:
Total empennage attach time: 6.3h Total empennage attach rivets: 26
I trimmed the hex posts to 2 5/64", which was the exact height to get the APU port's bottom flush with the doubler, then re-finished the trimmed ends - not as good as the original, but good enough:
APU port hex post finish (mine on the left, original on the right)
We then primed the "bottom" edges of the bottom skin which actually go inside the side skins:
Inside portion of the bottom skin's bottom side
then removed the vinyl from the rivet rows:
Vinyl removed from bottom skin rivet holes
Vinyl removed from the side skin rivet holes
I match-drilled the antenna doublers to the bottom skin:
Aft antenna doubler
Forward antenna doubler
then riveted them and the APU port doubler:
Test fitting the ADS-B antenna
Riveted antenna doubler and APU port doubler
Riveted antenna doublers
Before riveting the APU port doublers, I had also riveted the camloc receptacles to them:
Riveted APU port doubler and cover
APU port cover in place
Then came the time to cleco the whole thing together again, for final riveting (except for the F-1006 frame, still with vinyl on):
It all comes back together
Like others, I was initially confused by the order of the bottom skins shown in the drawings, which suggest that the aft bottom skin should go outside of the forward bottom skin:
Rivet goes on aft bottom skin? Nope.
Thanks once again to VAF, I realized that wasn't the case - that one rivet does go on the forward bottom skin.
For the actual inside riveting, I found that's incredibly easier to do with help from another person, and I chose to back-rivet most of it that way:
Wife (underneath) holding the bucking bar while I back-rivet from the top
So far, I have the side and bottom stiffeners mostly riveted:
Right side riveting progress
Left side riveting progress
Inside view of the riveted stiffeners
With this, I riveted the first of the avionics rails to the bottom stiffener, using CCPQ-43 rivets:
Avionics rail riveted to the right bottom stiffener
I also riveted the bellcrank ribs to their angles and the conduit holders:
Bellcrank ribs with angles and conduit holders riveted
as well as the avionics shelf nutplates (I added both the #6 and #8 nutplates so I have more options later):
Avionics shelf with nutplates riveted
I'll likely spend 2 or 3 more weekends riveting before I'm done.
Time lapse:
Total tailcone time: 168.7h Total tailcone rivets: 771
I also riveted the static line T bracket in place:
Static line T angle bracket
I attached the Panduit conduit holders to the frames:
Panduit conduit holders attached to frames
I cut the NACA vent doublers from .040 aluminum:
Cutting NACA vent doublers
then drilled their holes and match-drilled into the skin:
NACA vent drilled in place with doubler
I riveted the NACA valve bracket to the top stiffener:
Riveted NACA valve bracket
After I assembled the APU port covers (put the retaining washers to hold the studs), I also had a "oops" moment when I realized that the washer did not fit inside the countersunk portion of the hole:
Oops - it doesn't sit flush!
The solution was to use a step drill to get rid of the countersunk border altogether, opening up the hole for the washer to fit through:
Enlarged hole for retaining washer
With this, the cover plate now sits flush:
APU cover plate sits flush now
Camloc receptacle height for APU port adjusted
APU port cover test fit
I also realized that I hadn't primed the "exterior" part of the bottom skin which actually goes inside the side skins. I marked those and will apply primer there as well (as soon as weather permits).
Finally, I'm trying to decide whether to rivet the avionics rails to the stiffeners before or after they're attached to the skin (either way, the second set of rivets is harder to set):
Avionics rails clecoed to the stiffener
Time lapse:
Total tailcone time: 133.3h Total tailcone rivets: 209
