Heated Pitot/AOA

I am looking for advice on drilling extra holes in the ribs, before I assemble them to the spar. I am going to go with the Garmin GAP 26 Heated Pitot Tube w/AOA and it looks to have two tubes coming out of it. Has anyone installed all of the wiring and tubes in the left wing? How did you run the wires? Did you just follow the holes that Van's suggests or did you add extra to accomodate additional tubes? I have noticed from a couple of build sites, builders wished they had added the holes before they attached the ribs to the spar. Thanks for that advice.
Stoney

I ran both the pitot and angle of attack tubes on my 7A quick build in the small rib holes provided by the factory, and ran wires for LED navigation, strobe, landing, and pitot heat by drilling #30 holes in the top of the flange around the wing rib cut out holes. I then used these holes to fasten the wire bundle to the ribs with zip ties, incorporating an offset to prevent chafing. This was one of the methods suggested by Van's.

I ran the wires in the same rib cut out used for the aileron push tube, but now that I am flying, I wish I would have used a rib lightening hole further aft and brought the wires into fuselage well aft of the control stick to make maintenance easier.

I have an ADAHRS unit in the rear fuselage, and back-up altitude and airspeed gauges on the dash. The additional tubing for the angle of attack and interconnect between ADAHRS and steam gauges took some head scratching to locate. This aspect of my build would have turned out better had it been planned and installed prior to fuselage construction.

Jay
C-FXPT

In the RV12 there are holes in the ribs for snap bushings through which the wires are run. If you have those, maybe make them just a bit bigger (unibit) and add in the tubing. All size snap bushings are at Home Depot. Leave a pull string. Note that AeroLED lights - maybe others - have a special feature that synchs the strobes by running one common wire from strobe-to-strobe. You would hate to want to run that wire later...

Pitot

jay bell said:

I ran both the pitot and angle of attack tubes on my 7A quick build in the small rib holes provided by the factory, and ran wires for LED navigation, strobe, landing, and pitot heat by drilling #30 holes in the top of the flange around the wing rib cut out holes. I then used these holes to fasten the wire bundle to the ribs with zip ties, incorporating an offset to prevent chafing. This was one of the methods suggested by Van's.

I ran the wires in the same rib cut out used for the aileron push tube, but now that I am flying, I wish I would have used a rib lightening hole further aft and brought the wires into fuselage well aft of the control stick to make maintenance easier.

I have an ADAHRS unit in the rear fuselage, and back-up altitude and airspeed gauges on the dash. The additional tubing for the angle of attack and interconnect between ADAHRS and steam gauges took some head scratching to locate. This aspect of my build would have turned out better had it been planned and installed prior to fuselage construction.

Jay
C-FXPT

Click to expand...

Hey Jay, do you have pictures of what you did.

jswareiv said:

I am looking for advice on drilling extra holes in the ribs, before I assemble them to the spar. I am going to go with the Garmin GAP 26 Heated Pitot Tube w/AOA and it looks to have two tubes coming out of it. Has anyone installed all of the wiring and tubes in the left wing? How did you run the wires? Did you just follow the holes that Van's suggests or did you add extra to accomodate additional tubes? I have noticed from a couple of build sites, builders wished they had added the holes before they attached the ribs to the spar. Thanks for that advice.
Stoney

Click to expand...

Perhaps you can have a look a this thread. http://www.vansairforce.com/community/showthread.php?t=102965

I've been asking myself basically the same question. I called Van's tech support and was told that I could had a hole in the ribs to accommodate Pitot/Static plumbing. I'm still not sure if I'm going with Garmin G3X or Dynon's Skyview. One thing for sure, I intend to make provision for plumbing passage even if I don't install them readily. One day if I decide to install back-up instrument, it will be just a matter of threading a plastic tube from the wing up to the gauges. I've put some details in my building logs.

Pictures of Angle of attack install in 7A

Hi Bill, sorry for the delayed response. We had a couple epic winter flying days, and I just adopted an un-started RV4 project.

Here is a photo of the installed ADAHRS in the rear fuselage:
I have back up steam gauges on the panel in addition to the rear mounted ADAHRS unit, so I teed the static line in the rear fuselage and ran a line forward, and also teed the pitot line under the pilot seat and ran a line forward and aft.

Here is a photo of the A of A line running aft to the rear fuselage:

I drilled holes for grommets in the side fuselage bulkhead ribs for these lines because the quick build floor came riveted from the factory. I will run these under the floor if I have the chance to do it again

Here are the tubes and wires mounted through the wing ribs
I would have preferred to run the wires in a lightening hole further aft. The adhesive is a tough commercial sealant to stop chafing the pitot or A of A lines

I find it interesting to be writing on this this topic now, because I was uncertain how to handle it a couple years ago when I was completing the wings and fuselage, and paid close attention to what others were doing. Now that my airframe has 100 trouble free hours on it and I am planning my next build, I would offer the following suggestions:

Plan all your systems before you close any structure, and run all the required wires in advance. I got too focused on completing the primary structure, and paid for it later by performing wiring yoga in the completed airframe. In addition to pitot tube plumbing and wiring in the wing, consider antennae, nav light, stobes, syncronizing wire, landing light, wig wag, fuel gauge, auto pilot servos, and the associated grounds. In addition to the ADAHRS in the rear fuselage, consider ELT, Transponder, nav/com, ADS-B, position light, OAT, trim, and other remote equipment. Even if you don't install equipment now, run the wires if you think you may want it later.

I have practiced landing in day VFR with instrumentation covered up, and will not bother with back up steam gauges in my next build.

I much prefer AN rubber grommets to Van's plastic grommets for running electrical wire. The plastic grommets work fine for pitot static plumbing.

Look for opportunities to run multiple devices on shielded multi conductor wire to save weight, money, and clutter.

Jay