Avionics Fired up and no smoke !

I am not out of the woods yet, but I did reach a little milestone this weekend where I fired up the avionics and kept all the smoke in the wires.  Everything went well, although I used my back up circuits to power most of the avionics..  But it’s good to know that the backups work.

In my case I am choosing to back up 4 instruments in case of an electrical problem.  The Skyview has its own back up battery so I am not going to back that one up.  My theory on back up is only back up for a single failure..  Backing up for multiple failures is not prudent in most aviation circumstances.   A multiple failure would be something like backing up the backup battery of the Skyview.


The four instruments I am backing up in the case of a total electrical failure are below.  I chose these instruments because in the event of a failure, if they are the only ones available on battery power I could still get safely to a safe landing spot. 

TruTrak Gemini

Audio Panel

GTN 650 Com

GTN 650 Nav

Since I have a VP-X I had to separately isolate all four circuits so I am using a set of diodes similar to Jason’s project.  You can find his build site from the home page of my site.  Anyway, these are basically like one way electrical valves that keep electricity from back feeding the entire system when the essentials bus is turned on.  You don’t want to back feed the whole system because it would drain the battery too fast and also probably blow the switch because my e-bus switch is only a 30 amp switch.  Anyway, long story short when I flip the e-bus switch it bypasses the VP-X and runs power straight from a connection on the battery to these four devices.  This would be necessary in case of a total VP-X failure, or a master contactor failure or any wiring failure upstream of the VP-X.   So there are lots of reasons to have this safety feature.

In this pic, you can see the diodes where you have the Gemini and audio panel on the top and the GTN Com and Nav on the bottom.  I will need to label them and clean them up a bit..

Panel and Avionics

I think I am making progress, but sometimes it’s hard to tell.   Maybe over my head a bit right now with wires, but soon they will find their correct path.  One wire at a time like everyone tells me, but if that is the case then where did all these hundreds of wires come from..   ;-)

I can’t really explain all the stuff I did since I am kind of in autopilot and just cranking away at the next item that calls my attention..  I will do my best to cover what happened this weekend.  I found good routing for the Arinc wiring but haven’t connected it yet, also included the pilot mic and headset wiring with this path..   I installed the harnesses to the back of the radio trays and wired up the antennas to the GTN.  Installed the Gemini and fired it up for the first time.  Riveted the frame around the panel so that I don’t have to worry about this later.   Basically my panel is completely cut except for the seat heat switches, ELT, and annunciators.  I think I am pretty happy how it is turning out.  Eventually it will be a dark grey, probably same color as the carpets when I get them.  I also started hooking up the Dynon D-37 pin connector which is the main backbone of the Dynon.   I connected the GPS antenna, also ran the wiring from the Dynon to the VP-X.  All power and ground wires are ran for the Skyview but I am too chicken to turn it on right  now.    ;-)

Misc FWF and Avionics

Over the last few days I have been trying to figure out what to do next.   I am pretty much beyond the instructions/plans now so am basically on my own with some help from other internet sites.  There are many ways to do things, but for me I decided to try test fit all my compnents behind the panel before I drill anything or run any permanent wiring.  The attached pic is what this looks like..   Crazy busy, but its good to be able to try to figure wire runs and make sure I have everything in a reasonable place before I start drilling and fitting.

I did take the plunge and drill an additional hole in the firewall for the alternate engine air cable.  The spot I picked is out of the way on the engine side, but yet gives me lots of options on the cockpit side for the cable run.   I think I will be happy with this location.  Oh, and anywhere you see zip ties, is most likely temporary.  These will be replaced with appropriate fasteners down the road.

I also am hoping to get some final steps completed on the Baffles, hoping to get to paint at least the rear baffles this weekend.  For now I am drilling some blast tube holes and locating runs for the electric ignition and plug wires etc.  Also starting to work on the rubber air seal material, which is a completely different experience.

Avionics and Inlet Farings

This weekend was a crazy weekend on the plane.   I don’t even know where to start.  Friday I received my oil cooler from Niagra (20006A Model) and a huge bunch of avionics from Dynon.  Basically I got everything from Dynon in one package, so over the next few weeks will start digging all of that.  The oil cooler is going to be a problem, its huge but was recommended by Aerosport power..   It has 13 oil bays in it and is the same one used for the 6 cylinder 250 horsepower engine.   So I am pretty sure I can get by with a smaller one, I am thinking that 11 bays would do the trick and fit much better in my application.  I’ll follow up with Aerosport and the oil cooler company tomorrow.    

This discouraging oil cooler news didn't slow me down though, I really got through a lot this weekend.   The Inlet farings are basically done, I epoxied them in place and used some 2 part expanding foam under them to shape them the best possible shape for the baffles.  This piece of work is more art than construction, but I got through it.  Now all I have left to do is some final sanding and a couple layups of fiberglass over the foam and I am finished with them.  Also, I have some additional trimming on the front baffles, but that will happen over time.

After working with the foam on the cowling, I was ready to work on something that wasn’t pink..   So I started looking at the avionics and was able to install the GTN 650 Antenna.  I made a .060 back plate that has nutplates on it, and is separately rivted to the skin.  This makes for easy install from the outside.  I chose this location because it is per spec from Garmin, and is far enough away from the ADAHRS so no interference with the Dynon..

I also Installed the Pitch Autopilot servo and  the ADAHRs with Brass Screws.   You can’t use any steel near the ADAHRs because it will interfere with the sensitivity of the compass.  I still have work to do on these, but the big brush strokes are done.   I need to install the terminal on the antenna cable, and connect the autopilot servo and the ADAHRsto the Dynon network, but I am pretty happy with getting all this done.

I am just realizing now that I don't have pictures of the autopilot servo install, but  you will see that in future pics I am sure..

Its funny how some parts of the build like the baffles take forever, but then you start working on other aspects and you can move along seamingly fast.