Locating Remote Avionics in an RV-8

On the RV-8 that I'm helping build we had to find a place for the GTX23ES remote transponder and the ACK 406 ELT. Additionally, we needed to modify the rear battery tray to accept an Odyssey PC-680 battery. The tray as shown in the plans is really too big for the Odyssey. So we modified the battery tray so that we could mount the transponder and ELT thus:







Here with the equipment installed:



And in the airplane:



We used a sheet of .063 cut out as shown and riveted it to the bottom of the battery tray and reinforced with 3/4 X 3/4 X .063 angle. Also, we had to modify the angle stock around the battery for a better fit. It came out very sturdy. Yes, it adds a little weight, but we think we more than made up for it with the lighter Odyssey battery. Just food for thought for others contemplating the same problem.

I like it Pat. I'll remember this for the next install. Thanks for sharing.

+1
Makes me want to build another -8

nice job

Pat,
Finding a place for all the ?stuff? in a -8 is a challenge and your solution is elegant!

I have big-bubba friends that want to fly in my -8 ?.. so to keep the CG as fwd as possible I mounted my GTX23ES remote transponder under the avionics shelf. It slides in and out with no problems. If anyone else does this be careful to leave room at the end for the connections.

Since the picture was taken I swapped from the GSU 73 to two GSU 25 AHARS. I also had to build a bracket to hold the GAD 29 ARINC and GEA 24 engine monitor vertically instead of lying flat on the avionics shelf. It all fit?. Just barely!

Bob, my install is nearly identical - my transponder is on the left, spanning the Z-brace to the baggage compartment bulkhead. My remote COMM spans the same gap on the right. I have a shelf above the remote COMM for other hardware.

406 antenna

Pat, where are you putting the 406 antenna

gator said:

Pat, where are you putting the 406 antenna

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Looks like we're either putting it on the rear seat arm rest or under the tail fairing. We're going to do that this evening, but I think we're leaning towards under the fairing. Not ideal, but with the -8 you have to make compromises, and this seems like the best alternative to me, having done it many times before with the other model RVs.

bobmarkert said:

Pat,

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Long time lurker coming out of the shadows...

I just wanted to say I love that panel/cockpit layout.

Ooooh, side panels!

I don't want to take you too far off-thread either, but I'm interested in the wider side panels you installed. Your design or is there other information about this configuration floating around? How much hip room did you sacrifice to put them in? What was the need you met by doing this?

Any chance you could start another thread about them, or send me on my way to another thread already there?

I like em!

lots of work

Clay,
I'll send you a PM later but just let me say the sides added 2 months to the build and have a lot of unintended consequences (i.e. rear throttle will take a custom built and designed cable) etc etc. LOTS of custom brackets behind the curtain. Jim Gray (Award winning RV8 at Oshkosh) is the craftsman that deserves credit for them.

Looks good Pat.......have you decided where to put the aerial for the ELT?

Cheers
Tony

Tony, looks like we're going with the tail fairing location, working on that now. I'll post some photos when we're done.

In the end, there was just no good way to mount the ELT antenna in the tail, so like many others, we went with the back-seat armrest location.



Here with the canopy closed:



It works quite well as far as the physical location. There is no interference with the canopy at all and we plan on adding a UHMW catch near the shoulder harness slot to capture the little plastic ball at the tip of the antenna for loading baggage or access to the rear. This will force the antenna to follow the contour of the seat back frame. The seat back would otherwise probably catch on the thin part of the antenna. We would release the catch for flight, of course.

I suspect that antenna performance would be less than optimal, but probably still quite adequate. I've seen some odd-ball antenna locations that worked pretty well. We'll see if there's any way to test it with SAR after we get into phase 1.