Category Archives: Pitot / Static System

Stabilizing success

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I skipped a major step during the tailcone build sequence by never installing the horizontal and vertical stabilizers onto the tail cone. I didn’t see a point of doing that in the garage just to take it all apart again for storage for years. Now that I’m in the hangar and have the room, no excuses are left. I didn’t build either stabilizer, as the original tail kit owner built them. After looking over them and cleaning them up, I “touched up” a few of the rivets I felt were under squeezed. They aren’t primed on the inside either but even after 10 years of sitting around, they are looking good and corrosion free.

The process went as planned and I spent the better part of one full day getting it all drilled and bolted on. I had purchased the CNC brackets from somewhere to mount the horizontal stab so I didn’t have to make them. I have no clue where I got them from, however, as I bought them on a whim years ago. Either way, they’re nice and you should buy them.

The only hiccup came when working on the elevator trim cable. The original builder had installed the plastic snap bushings the trim cables run through while building the stab. Unfortunately, he put the wrong size bushing in one of the holes that was buried in the spar. The cable wouldn’t pass through. Fortunately the hole was the correct size but man was it a pain in the ass and fingers getting that old one out of there.

Laura helped me bolt the rudder on next to set the rudder cables up and do some trimming for the rudder trim wires and tail light wires. All easy stuff and its really exciting to see the tail feathers finally get attached.

I was able to finally hook up the elevator torque tube after drilling the horns. I was careful to get them lined up accurately and am pretty happy with the end result with the right elevator being lower on the trailing edge by about 1/16″.

I then set out to start the rigging process by centering the stick and adjusting pushrods to get the control surfaces all lined up. It takes quite a bit of stick movement to get the control range established by the plans and I found some interference with a bolt on the aileron rods under the seat pans. I was able to switch the bolt orientation and it cleared right up.

The autopilot roll servo went into the right wing pretty easily as well. I had the mount installed during wing construction, so it was a matter of bolting it in and attaching it to the aileron bell crank. The wiring hooked up quickly since I had already ran the wires and installed a connector.

I cleaned up a bit of the wing root area as well, hooking up the CPC connectors, pitot/AOA tubing, and ensured it all cleared the control rods inside. I had planned to mount a bracket holding the CPC and pitot/AOA tubing somehow, but the whole bundle is so stiff, I’m not too concerned with securing it further. It’s also well clear of the torque tube despite the appearance in the picture.

Finally, we had some good light from the sun on the propeller and I couldn’t help but drool over it for a few minutes. The orange over black with the polished leading edges are just too damn cool looking. The scimitar shape is sexy too!

Punching the punch list

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There are a lot of little jobs that go along with the big jobs on building a plane.  I’m trying to use my time efficiently while waiting on the engine to knock out a bunch of them.  The first was fixing the arms and servos on the heat ducts up front.  An order to ACS and a few minutes at the band saw and the servos for the heat and oil coolers were attached properly and pots adjusted for full travel.  I also spent an hour trouble shooting a bad pot for the rear heat duct, as I have a switch that allows either the front or rear rheostats to control the servo and the rear rheostat was inop.

I cussed and bled in equal amounts installing the last of the seat rail brackets now the gears are on.  The nuts and bolts are not easy to access at this point, but you have to wait in order to install the gear bolt.  I also put in the last bolt and custom spacer for the GPU plug which helps reinforce the receptacle by attaching it to the seat pan.

I ignorantly forgot to install the transponder antenna before buttoning up the tunnel, so I had to take the center console, tunnel cover, and lower instrument panel off to get down in there.  Of course I burried it near the core of the earth which made access tricky to say the least.  I was able to squeez my hands down there and got it all bolted on with the coax attached.  I knew I had left one fuel line untorqued but couldn’t remember which one so checked all fuel line fittings for proper torque.

The last task in the rear tunnel is to secure the aircon lines which I did with some hose clamps and edge grommet material.  Again, not fun to get to the hardware but it was doable and will rarely if ever be removed.  The lines are now secure and fit nicely in the tunnel, I’m glad I didn’t run them down the side of the fuse.  I also secured the last little sections of the O2 lines in the tunnel.

My ELT antenna placement has been a topic of disagreement on VAF, as I really wanted to avoid mounting it on top of the tail cone.  It’s big, ugly, and ugly.  Mainly, though, it’s ugly.  It’s also essential to my life and the lives of my passengers should the worst happen and we have an accident, so I guess it’s important to do it right.  I debated on doing some reception tests with it mounted internal to the tail cone, but honestly, I just got lazy and decided it really isn’t that ugly.  In the end, I chose to do it the right way and put it on the top of the tail cone.  The cable was secured along a bulkhead and the last of the wiring clean up for the O2 tank / ELT was completed.

I love spending time wiggling back into the tail coffin, I mean cone, so I made a fort with blankets and towels and dove in to attach the OAT sensors to the ADAHRS and finish securing tail cone wiring.  I put the OAT sensors below the access panels underneath the horizontal stab since I had all of my wing wiring complete and for shorter wire runs to the ADAHRS.  Since they have to be calibrated anyway, I’m not too concerned with exhaust from the engine affecting them too much.

The O2 tank was put back in for good and connected to all of the lines.  I also attached the pitch auto pilot servo to the bellcrank and will connect the yaw servo once the tail feathers and rudder cables are rigged at the hangar.  That is the last task in the tail cone and can be completed without having to crawl all the way back there.  It’s going to be motivation in life to keep from getting fat or have a small child that can slide back there for maintenance, it’s a very tight fit with all the extra stuff I put back there.

More zip tie work on the side walls as I cleaned up all of the wire bundles.  I was lazy and didn’t lace them.  If you don’t like that, you go build your own damn airplane!  Lots of zip ties.  Overall I’m happy with the wire runs, I was able to keep coax with mainly data / signal wires and have the high current ones seperated.  I have seen plenty of aircraft with everything bundled together without issues, so I think it’s more important to terminate and ground properly than anything.

The pitot / AoA tubing needs to run across the fuselage from the left wing to the right sidewall, so I put two holes in the tunnel and used free holes from the fuel line anchors to run the blue and green tubing.  The wing is already plumbed, so these lines will connect with those from the wing with two connectors and be done.

Finally, I put the 30 amp Schottky diode on the firewall between the shunt and engine fuse block.  I had this in my electrical design but just in the wrong location.  It provides redundant power input to the engine fuse block only, keeping it from backfeeding the rest of the electrical system.  The power comes in from the emergency engine power switch which comes from the battery to the fuse block.  Big picture, it is a redundancy for the single point of failure of the master contactor or short in the system.  A complete electrical failure or engine stopping SOP will be to turn off the master switch (leaving PFD, MFD, and G5 operating on independent back up batteries) and switch on the emergency engine power switch.  If the battery has any juice at all, it will go only to the engine fuse block.

Staying in the lines

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Throughout this progress, I’ve been finishing up the brake lines.  I ordered extra line for the run from the firewall to the gear legs and got them all fabricated.  The lines weren’t hard to make, but it was a bit tedious.  I am happy with the end result, however, and think that it will provide many years of great performance without having to worry about replacing tubes.  I do need to get some spiral line wrap to prevent chafing and that will allow the lines to be a bit better secured.  Mark Ciglia put his parking break valve in place of the firewall connections, which I’m mad I didn’t think about.  It makes it a bit cleaner and eliminates one extra set of lines, but oh well.  It’d cost more now to redo it.  Note to other builders!

I also knocked out a few little projects, one being making new elevator trim bracket panels.  I had the beefed up fittings sitting in the parts bin and finally ordered the new access panels.  After countersinking and priming, the parts are ready to roll and comply with a SB from Van’s from many years ago.  This is a common upgrade and an easy one at that.

Another little project wasn’t so little.  I saved up a few tasks that needed to be completed inside the tail cone for one evening so I would only be crawling back there once (this time).  The first was to support the tail better.  I used two 1×4’s to bolt to the horizontal stabilizer mounts and put a caster on the bottom.  While the fuselage cradle has been great, the rear support isn’t far enough back to support my weight so far aft without something heavy like an engine hanging off the front.  So this was an easy fix and doesn’t take any room up in the shop.  It’s still very easy to roll around and reposition as needed.

Inside the tail cone, I mounted the new static ports with pro-seal (no rivets this time) and hooked up static line that runs to where the ADAHRS will be mounted just behind the baggage bulkhead.  The new static ports look way better than the original ones and I’m happy I made the change.  The Safe Air 1 line kit makes it easy to run the tubing and create a leak free system.  I also ran the rudder cables through the bulkheads and snap bushings.  Ironically, the heads of the cables wouldn’t fit through the bushings without removing them and squeezing a bit.  So basically, the cables were a pain to run instead of a quick two minute job.  Lots of those in the build, I guess.   I got them hooked to the arms on the rudder pedals which are inside the tunnel with the Control Approach pedals.   With the A/C in there, it’s a tight fit for me!

Lastly, I installed the doublers along the center of the fuselage for the transponder and ADS-B antennas to mount to.  These will be Delta Pop blades and mount with two studs, so I need access from the tunnel / fuselage.  Easy enough with a second set of hands to man the gun and me bucking.

One F*&$#ng Bolt

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Even though I don’t have the stabilizers mounted, I need to run the rudder cables so that I can start putting other components in the tunnel and move forward with systems layout.  The rudder cables get threaded through the tail cone skin and forward.  Unfortunately, the ends don’t fit through the snap bushings easily and will require me climbing into the tail cone to thread through the bulkheads.  More on that plan later.  I could, however, go ahead and clamp the plastic tubing to the fuselage using cushioned adel clamps where the cables exit the fuselage.  What should have taken about three minutes to put a clamp on and secure it with an AN3-5A bolt wound up taking over 30 minutes and resulted in a lot of frustration.  The clamp proved to be just springy enough that the threads wouldn’t engage and it’s already a tough spot to reach.  With my patience running out and my fingers sore from messing with the bolt, my gut instinct to scream profanities targeted directly at the airplane proved successful and I was finally able to get the little bastard in.  I will never, ever, ever take that bolt out.

Needing to lower my blood pressure and calm my headache not to mention my now very concerned shop dogs, I decided to move to another aircraft system, the pitot static system.  I ordered a kit from Safe Air 1 quite a while ago and have already installed the pitot tube mount with preliminary tubing in the wing.  When I built the tail cone, I used another brand static ports that after looking at for years had to go.  The Safe Air 1 ports are designed to be mounted from the inside and have a very clean look not to mention good reviews of functionality.  Since I was going to have to crawl in the tail cone anyway, I decided to remove the current ports to prepare for the Safe Air 1 version.  I had to drill out the four rivets, clean up the holes, dimple them, and make a patch.  The patch is required since the original ports had a half inch hole required.  I had to get pretty creative on how I dimpled the holes since I can’t get the pliers or squeezer on it.  I wound up using the blind rivet nail trick with the dies designed for a finish nail with great results.  Once the patches were made, I used blind rivets that sit nicely in the skin for ease of use and negating one more task of bucking rivets while crawling in the cone.  Since I’ll use flox filler to smooth out the hole anyway, the blind rivets will disappear.  I’m really happy with the result and quickly relocated the new port hole just below the original location.  I don’t anticipate any issues with the new location.

I also installed the avionics shelf that I had fabed previously with the proper spacers and screws.  I plan to use nutplates for permanent mounting of components once all of the boxes are laid out.  I’m preparing everything I can think of to do while crawling in the tail cone to include mounting the new static ports, mount the static line and clamps, route the rudder cables, install snap bushings for tail wiring, and run string to pull future wires.

Bite my shiny metal bottom…skin

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After a visit from my EAA chapter tech counselor and a great report card, I was confident in buttoning up the wings with the bottom skins.  It takes a lot of clecos to position the skins and a lot of time spent drilling and deburring.  Then the dimpling fun begins and priming.  


The riveting process is another dreaded task, besides building the tanks.  You have to start with the rear spar and bend the skins up.  I used duct tape to help hold them in position and allowing me to rivet a few rivets at a time working from the rear down each rib.  


Overall, it really wasn’t bad.  I managed to get the entire skin done alone except for three rivets where my arms just weren’t long enough.  I had the wife man the gun for those on the j-channel.


On the left wing, I installed the pitot mount. I also got the aileron trim servo hooked up mechanically and electrically with a micro Molex connector.  I was worried that the springs on the setup would be a pain to install, but again, it wasn’t too bad.  No picture, as once the springs are on, the access panel goes on.

Finally, before replacing the aileron and flaps, I complied with the service bulletin regarding the aileron mounting bracket. Other builds have suffered cracking and the gap fairing must be cut back to allow inspections at regular intervals.  Replacing it is not recommended per Vans, as it can cause more damage trying to remove the rivets than replacing it.   A quick job with the Dremel tool.

Excuse me Sir, but your pitot is showing

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Turns out, the pitot is much easier to install before putting the bottom skins on.  I learned this thanks to the great info from other builders’ blogs.  Check out the link Other Build Logs for some of my go to’s.  It’s good advice, as it gave me a lot of room to mount the heater controller and the actual mount itself.

I’m putting in the Dynon heated AOA and pitot tube along with the Safe Air mount.  Great products all around and the process wasn’t too bad.  First step is marking and cutting the hole in the skin.  Safe Air provides a nice template for this and a Dremel makes quick work of the task.  I chose to use the standard Van’s location just inboard of the tie down location.


I used a bottoming tap to carefully cut threads in the pitot tube, making sure the drill and tap stayed clear of the tubes.  I also installed the fittings which allowed me to use the new crows foot wrenches.  It did surprise me how much torque they require, as I was afraid of ruining them.  But they shouldn’t leak now that they are good and tight per the specs.



I also got to break out my Stein wiring kit for a connector and pins.  I’ve used a similar crimper before, so the hardest part was figuring out which pins went into which side of the connector.  I shortened the wires to reduce the amount of slack wiring inside the wing and put the pins on with ease.  The only thing left to clean up is putting some braided sleeve on the wires to provide some abrasion resistance and spruce them up a bit.


One piece of advice is to mark the wires coming from the pitot itself before cutting off the spade connectors.  There is a blue and orange connection from the controller but both wires from the pitot are white with a corresponding piece of heat shrink on them.  I had to email Dynon and get a trick to identify which wire went to blue / orange.  They advised a great trick to freeze the pitot and determine which is blue / orange by seeing which side of the tube heated up first.

I originally mounted the controller to the access panel as others have done, but didn’t like that with having to tuck wires in so I decided to follow another builders idea of putting it on a rib.  Adding four nut plates makes it a clean instal and still allows easy to access once the bottom skin is on.  Overall, I’m very pleased with the install and looking forward to having the integrated AOA display in the cockpit.