Neal – Page 9 – RV-14 Build

Panel Test Fit

Posted on April 19, 2024 by Neal

Tonight I installed most of the panel components in an effort to test-fit everything. I wanted to ensure I identified any interference issues, and verified I had enough length on the various cable runs.

I started by installing a bulkhead attach for the Nav antenna in the right wing. To make this as strong as possible I installed a bulkhead fitting under the passenger seat, where there will be no sheer loading on the fitting or the rib. The fitting from the wing will be too wide to pass through the outer rib without taking the snap bushing out, so I cut a slot in the snap bushing to allow it to be removed, the cable and fitting installed, and then the snap bushing can be opened up to go over the cable, and be reinserted in the hole.

Next I started installing components. I started with the switch panel, which required some adjusting around other panel screws, but eventually fit perfectly into position. I installed the flap switch handle and plugged in the connector from the ignition switches.

Then I installed three PFD, no problems. Then the G5, which again went in without difficulty. Everything looks good on the pilot side. I took the opportunity to power up the G5, since it has a standalone battery. It was cool to see the airplane “come alive” for a couple of minutes.

Switching to the passenger side I installed the MFD, and noticed a problem. The d-sub connector on the back of the MFD is very close to the connector on the back of the engine monitoring box. There clearance will be ok if I can find a way to route the MFD connector cable around the outboard side of the various equipment boxes. There’s just not enough length on the connector to do that right now. It’s possible once the wiring harness is in its final location that I can do just that.

In the center of the image, the MFD cable is routed between the two connectors on the right. If I could route the cable towards to camera (outboard), I could fix the issue

The panel, just missing the G750 and autopilot panel

Pitot static lines

Posted on April 18, 2024 by Neal

Tonight I started on the task of running pitot static lines from the wing attach point to the panel. There are two lines that run in from the wing, a pitot line and an AOA line. They will t-off behind the panel with one line going into the back of the AHARS, which is mounted to the back of the PFD, and the other lines running to the G5 backup instrument.

This ribs already have one set of holes running through the seat ribs that is just the right soze for one line. There are other holes too, the outboard ribs have two additional holes for installing gear leg bolts for tri-gear models. The inboard ribs have tooling holes. I enlarged one of three tooling holes on each of three two ribs under the pilot seat, and installed snap bushings. Conveniently, the spar already has two holes I can use to run these lines forward of the spar and into the center tunnel.

I’m planning to install quick connect fittings somewhere under the pilot seat, probably on one of the inboard ribs. I ordered a few fittings from Stein Air and will tackle that when they arrive.

Shavings visible for enlarging the top hole. The angle of the camera makes it look like these holes are closely spaced, but there’s over an inch edge distance.

After using the step drill to enlarge one of the tooling holes. I actually drilled a new hole to offset the center of the enlarged hole, ensuring enough clearance

Wing spar bolts

Posted on April 16, 2024 by Neal

The last step of attaching the gear legs is to install and torque 4 bolts on each side of the fuselage. With the tail wheel model, there’s not much going on in this area, because the gear legs are forward of the firewall, but for the tricycle model this is where the gear legs attach. Anyway, I had this in the to-do list, and tonight I installed and torqued up the 8 bolts, 4 on each side.

GPS and NAV cables

Posted on April 10, 2024 by Neal

Tonight I routed three GPS & XM antenna cables, and the NAV antenna cable through the fuselage, installed, tested, and connected the BNC and TNC fittings.

I started with the GA-35 antenna cable which connects to the back of the G750. I also installed snap bushings in the tunnel where I plan to run these cables and the pitot static lines. To avoid interference, I am routing the GPS cables on one side of the tunnel, and the ADSB, NAV, and COM antenna cables on the other side. This should help minimize interference with the GPS and satellite signals.

Next I ran the two cables connecting the GDL-51 antenna. One connection goes to the satellite receiver, and the other to the back of the G3X display unit.

Then I ran a length of cable for the NAV antenna from the back of the G750, down the tunnel, under the passenger seat, and near the edge of three fuselage. I plan to install a bulkhead BNC connector on the outermost rib, which will (hopefully) make for an easy connection after the wings go on.

GPS and XM on the left and ADSB on the right

The current mess of cables in the tail section. This will all get tidied up

Com Radio Cables

Posted on April 8, 2024 by Neal

Tonight I started work on the antenna cables beginning with the com radio antenna cables. I watched a Stein Air video on the simple process for crimping the BNC (and TNC) connectors. I had previously ordered a bunch of connectors and cable from Stein, so I had it all on-hand.

I ran the Com2 (passenger side) cable first. This follows the control stick cabling under the seat and into the tunnel. I routed it from the antenna to the remote radio box and then installed a BNC connector on the radio end. Then I estimated the length of cable I will need, and cut the cable to length at the antenna end. At that end, I installed a 90 degree fitting to keep the cable clear of the control stick and laying flat against the floor.

A repeat for the pilot side, except the cable crosses over to the right side of the tunnel to keep it clear of the GPS cables that will run on the left side of the tunnel. The panel end connects into the back of the G750.

The 90 degree fitting. Testing for any shorts with a multimeter

The 90 degree BNC fitting on the antenna

The BNC connector plugged into the remote radio box

Radio stack – G750

Posted on April 6, 2024 by Neal

Last night and tonight I worked on the G750 installation. This is the IFR nav radio unit, where flight plans are entered and managed. It sits above the autopilot module, and extends a long way back into the subpanel.

This unit has a rack much like the other Garmin equipment. The task of mounting the rack was a little tedious as I was trying to ensure the frame of the unit fit nicely on the panel, so I did numerous test fittings and fine adjustments. The forward attach points were challenging because of access, and proximity to the sub-panel. In hind-site, I should have moved the unit aft slightly to improve the location of the forward mounting holes, but I’m happy enough with how it ended up.

The aft edge (the front of the unit) frame attach holes. I ended up creating slots so I could adjust the height of the unit, giving the right amount of clearance

The forward (back of the unit) attach points, with screws temporarily installed. This side was relatively easy, the other side was hard because I have permanently installed shelving that blocks access. Lack of planning on my part

The backing plate on the left side. I decided to rivet this into place on the left side to act as a doubler, increasing strength of that area. This was too hard to do on the right side, so I didn’t rivet the plate into position on the right side

One of the many test fittings of the rack. In must have installed and removed the G750 unit a dozen times before finalizing the mounting location for the rack

How it looks with the autopilot and G750 installed. Note, the 750 screen has a plastic protective sheet on it, and the screen is not scratched

Radio stack – Autopilot

Posted on April 3, 2024 by Neal

Tonight I worked on installing the autopilot module in the center radio stack. I noticed an issue with the panel which I’ll have to address, but otherwise this went ok.

The GA-507 autopilot module will sit at the bottom of the center radio stack, under the GA-750. It has a rack that fits nicely inside the center stack, with two screw attach points on each side. Most of the work was to make a doubler plate with nut plates, and to line up the holes correctly. After some fiddling and experimenting I had a solution that seemed to work well.

The issue was with the left-hand most switch location. It is too close to the edge of the panel, and contacts the rib, pushing the center panel out of alignment. I emailed David who made the panel cutouts and I hope he can make a new plate with the hole moved over slightly.

It was cool to see the autopilot panel installed, the buttons and knobs have a great solid feel to them.

The go-around switch is too close to the edge of the panel, contacting the rib and pushing things out of alignment. David is remaking the center panel and will ship a new one

Taking the switch out allowed me to continue working for now

The autopilot rack temporarily taped into position so I can locate the screw holes

Once I had the rack screwed into position, I could install the autopilot panel

One of the backing plates with nut plates

WAAS Antenna

Posted on March 31, 2024 by Neal

Tonight I installed the WAAS GPS antenna. I’m placing the one behind the GA-35 GPS antenna, and offset to the right, just over 12 inches apart.

The process was the same as the other GPS antenna, although this one is slightly larger and has two 5/8 size holes for the connectors vs just one on the GA-35. Using the back-plate (purchased separately from Stein Air) as a template, I carefully selected the right position making sure it was parallel to the longitudinal axis of the airplane, and clear of the sub structure (j channels, ribs, bulkheads). I used the centerline of rivets to ensure it was parallel, and calculated the required clearance from sub structure, then placed it as far aft as I could. This location gave me just over 12 inches distance edge-to-edge from the two GPS antenna.

I drilled and reamed the holes, and used the step drill to step up the two large holes to 5/8.

Deburring the inside of the holes and then stripping the primer from the underside of the top skin was a challenging step. I had to climb into the baggage compartment then reach back to complete the tasks, which was doable with enough patience.

Dimpling the holes in the skin was also a challenge. I had to use my pop-rivet dimpler, which doesn’t give the best results on a good day, because there’s no other way to access both sides of the skin. I used a step stool to get up off the ground, and then I found I could reach back enough to inset the nail into the hole, and support it while putting the pop riveter into position. it was fiddly, but not hard.

I made quick work of the necessary countersinks, installed the nut plates, and then pop riveted the backplate into position.

I used some silicone and the rubber gasket to install the antenna.

Holes drilled. Starting to final size the #30 rivet holes, here I have the forward row complete

Nutplates installed. These are awesome, the threaded portion “floats” underneath the clasps on each corner. This allows the bolt to thread into the nut plate much more easily, and remain vertical

Top side of the backing plate with countersunk holes visible

Underside of the antenna. Despite how it looks in this picture, the backing plate is clear of the j channel, the closest point in the corner is approximately 1/8 of an inch clear

Relative location of the two antenna. This will add some drag, but hopefully not too much.

GPS Antenna

Posted on March 31, 2024 by Neal

Tonight I installed the first of two GPS antenna. This was the GA-35 and provides GPS signal to the G3X system. The second GPS antenna provides WAAS signal to the IFR navigator.

I purchased the backing plate from Stein Air, and it was great to have to mount holes pre-cut. I could then use it as a template to locate the holes on the fuselage skin.

I started by marking out the rivet holes that will hold it onto the skin, then I drilled the rivet holes into the backing plate. Then I taped the backing plate to the fuselage and carefully measured to get it square to the airflow, and at least 12 inches from the other antenna I will be installing, while also free from interference with substructure.

With the template in position I drilled all the holes into the skin. I carefully reamed all the holes to get it as accurate as possible.

After cleaning up the holes, I dimpled the skin, countersunk the backing plate, and installed the nut plates.

Then I was able to clean primer off the inside of the skin, and rivet the backplate on. With that done, I put a bead of silicone around the edge and torqued the screws to 16 inch pounds per the spec.

Countersinking and two nut plates have been installed

The inside view looking up at the bottom on the antenna

Comm Antenna

Posted on March 29, 2024 by Neal

Tonight I was able to install both comm antenna, and was surprised how easy it was. I bought the Rami bent whip antenna from Vans, and am installing two because I have two radios, the GTN-750, and a second, remote radio.

Vans ship the quick build with pre-cut holes for a smaller two-bolt antenna, but the doubled plate they install is fastened with 4 rivets that are in the exact location of the 4 mount bolts for the Remi antenna. This makes it easy, simply drill out the rivets, remove the doubler, install a new doubler, and mount the antenna.

The antenna ship with a doubler, which seems somewhat undersized, but I’ve used it anyway. If it ends up cracking, it’s easy enough to undo the nuts, take it off, and make a new one.

I had no issues drilling out rivets, drilling the center hole, and installing the antenna by myself. I used the rubber gasket, and a bead of silicon between the rubber and the aircraft skin, just in case.

I started on the passenger side, then did three pilot side. No issues on either side.

Enlarging holes to mount the passenger side comm antenna

Removing the primer is important to ensuring a good electrical connection with the airframe

The doubler with antenna installed and nuts about to be torqued

Author: Neal