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