Garmin GAP 26 Regulated Heated Pito Tube

 RV14 Build July and August

GAP 26

The RV plans have a simple tube for pito, so installing the GAP 26 especially the regulated heater takes some thinking and planning.

After lots of messing and testing locations I decided that I wanted to install the Pito tube 2 bays outboard of the access panel to get it further away from the tie down. But I did mount the the heater controller in the same bay as the most outboard access panel. I measured the heater holes and drew them out on the rib, drilled pilot holes and then put the controller up and final drilled.

I then installed nutplates. This was tricky to drill and one of them wasn't lined up because of the rib lightening holes.

I think 3 nutplates is more than enough, but I did put in the the fourth that I cut 1 of the lugs off and installed 1 rivet.

I ordered the Gretz Pito Mast from Stein. The plans assume you are installing with the wing skins off still so I had to change it up a bit. 

I bent a simple L brackets from scrap sheet metal and put the mounting plate on then used my ruler to level everything to how the bottom skin fits.

After putting the skin on and seeing where the rivet holes would most likely go I made a larger L bracket and a shim to replace the backing plate so I had better control to drill through. The 2 horizontal pieces of aluminum as there to line the bracket and backing plate to the correct height on the rib with the lower skin when installed.

I then drilled 4 holed in the L bracket and Rib. I plan on using MSP 42 pop rivets here.

I made another shim the same thickness as the spar flange, so the backing plate would sit correctly on the skin for drilling. I first clamped the backing plate to the spar flange and match drilled the holes in the plate. Then match drilled the holes into the shim so both would cleko to the skin. The edge distance was a little off so i stepped in 1 line of rivets a little and used my rivet spacer to drill these.

Next was to cut the hole for the pito mast.

Used the dremel router bit to kit out the middle.

The mast hole in the backing plate is a little undersized so you can grind it to fit, so I had to shape the backing plate and skin to the pito mast, but it made for a nice tight fit.

Last was to match drill the holes into the skin into the L support bracket on the rib.

I got a little lucky that the stock wires on the GAP 26 controller are just long enough from the final mounting locations to just come out of the mast for installing and maintenance in the future.

How everything looks with a service loop once done.

I haven't read that people have problems with magnetic interference on the magnetometer, but just to hedge my bets I twisted the power and ground wire I had to run to the GAP 26 from the wing root to GAP 26.
I am going to change 1 of the molex from a 9 pin to 12 pin to add room for the GAP 26 Power, Ground, and Discrete. The Common fuselage harness will need to be changed to a 12 pin as well, but ill do this when I am mounting the wings, because I think those lines will be need to be shortened anyway. The common fuselage harness does have a 14AWG line coming to the wing root that the power will go into but the Ground and discrete have to be run up to the panel.

The molex that I'm going to change out.

What a 12 pin looks like.

Enlarging the mounting bracekt.

Running the Ground and Discrete wires.

Ground and Discrete.

Installed some cable protection.

and an edge grommet for the lines making the turn down into the pito mast.

Took off all the shims and parts and primed.

GAP 26 15.5 Man Hours

Section 17 Outboard Leading Edge QBW

 RV14 Build July and August

Outboard Leading Edge

This section doesn't look like it should be much work, but I am making it way harder than it needs to be. Because I was sloppy and have had to redo work. 

The plans start with making cradles for the leading edge. I knew i was going to take the tanks off so I went ahead and made these.

I cut the cradles from the top lid of the shipping crate from vans, and use a length of 2x4 as a leg brace.

Fuel tanks off the wings and into the newly made cradles. Taking these tanks off was incredibly hard. The amount of force it took to remove the 50+ screws on each tank left a bruise in my hand and I still stripped a few and have to order replacements.

After the cradles the plans have you cut the slot for the stall warning. The skin has 2 small holes that you enlarge, then remove the material in the middle.

Stall warning opening.

Putting the stall warning assembly together was a little challenging as there are a lot of little bits of hardware.

Countersinking where needed.

Pictures of it all together before priming the metal.

After test fitting I had to bend the sensors tab to get the stall warning vain to have the correct orientation per the plans.

After priming, reassembly and install. This was actually several days later. I was missing a washer that went with the screws to mount into the nutplate.

Nice looking stall warning vain.

Next I started to work on the brackets for the access panel and the landing lights. I went off plans for the landing lights and went with the FlyLeds so this required some modification of the bracket that came in the landing light kit.

I didn't need to do and work on the mount brackets and landing light lense backing plates other than dimple and nutplates, so they all were primed in the large batch of parts I did in the beginning. I used a rustoleum flat black, this comes back to haunt me later.

Landing light lense backing plates

Since I have different landing light I needed to modify the mounting bracket, so I needed to know how big a hole I will need.

The mounting holes in the corner of the landing light kit are for the lights Vans recommends. You can see where I marked the holes to be drilled in red for the lights I have. Really glad the modification is relatively simple.

Match drilling the landing light holes into the brackets.

Then I primed and "topcoated" the landing light hole in the wings. This is where things went a little south. I used the wrong size squeeze dimpler, and when I re-squeezed the dimples the black started to crack and i noticed it was bubbled up in other areas. Bad surface prep.

First time using this tool, but the dimple looks good.

All Dimpled.

Now time to spray it black.

When I went to re-dimple the pant chipped and I noticed it was peeling in other places.

So out came the acetone, and i took it all back out.Clean bare metal, well prepped this time.

Re-primes with the SEM gray rattle can, I ordered Tempo Aircraft enamel black from Aircraft Spruce to try for the black this time.

For the time I moved on to the landing light lenses. First you trace the lenses and do a rough cut. Then you use the backing plates to measure and and do a final cut, debur the holes, chamfer the edges, pilot drill, use double sided tape to mount the backing plates, and final drill.

You can see some cracking on the edges, I was lucky and this was all removed in the final trimming.

The scothbrite wheel did a nice job of removing material.

Dremel router bit for getting close on the final cut then back to the scotch brite wheel.

Homemade plunger to help put pressure for the final drilling and screws.

Countersinking, start by hand get close with the cutter, finish by hand.

Chamfering the edges.

Hoving on to the access hatch. I decided I want to prep this for ER tanks in the future, so I need an access panel on both wings and only the left comes with one. I used the doubler and panel to make the template and cut the hole in the right wing. I ordered an additional doubler and panel.

Dimpling and adding nut plates.

Using the panel as a template.

I drew the X to try and find the middle of the corners and measures in .250" and drilled a pilot hole.

Opened the corners with the step drill to .5"

Then I used the nibbler to cut away the material.

Flipped the doubler and panel into the hole and used it as a template for the backing plate rivet holes.

Final hole, just needs to be dimpled.

Outboard Leading Edge QBW 28.5 Man Hours