Catching Up - Transport to Airport and More Issues (aka: fun)

After a nearly 4 month hiatus from documenting the project, it is way past time to catch up and let you know about the progress of N79AM.

She was transported to her new home, 27XS during the last week of March.  First shot below is load number one with one win, stabilator and rudder. Sufficiently padded, the trailer was pretty lightly loaded, but arrived without any injuries.

The loading of the fuselage was a challenge.  The main gear was too wide to fit on the trailer by about 3 inches, so I had to figure out a way to decrease the span.  The next few pictures show the convoluted process involved.  In the end, I started worrying about the rigidity of the assembly and the tendency to absorb road bumps.  We came up with some large foam pads from an old airbed that served to very nicely cushion the dollies on the mains.  The fuselage rode better than I could have hoped.  The thick foam worked beautifully.

A little detail of the main gear dolly.

Finally loaded and ready to depart from the home hangar to the real one, about 18 miles away.

One of the first tasks once in the hangar was to install the Warp Drive 3 blade prop. Initial layout and trial fitting reveals it is one fine piece of work.  It went together quickly and then was ready to attachment to the engine.

Below is a shot of the protractor-type device for setting a consistent pitch between each of the blades.

 Mounted the spinner and all is ready for more engine runs and eventually taxi testing prior to first flight.

I finally chose to install the fiberglass canopy trim piece and after much thought and debate, opted to use s structural silicone adhesive.  Eggenfellner had recommended the use of a very good Permatex product, The Right Stuff, but its cure time was way too short for the required task, so I found another competing product that cured in 2 hours, plus it had superior adhesive properties.  Pictures below show it drying under the pressure of painter's tape and a wratcheting strap.

One of the next issues to arise involved a fellow Viking-engined RV-12 whose newly flying craft experienced vapor lock on several occasions.  The builder had chosen to follow Eggenfellner's latest recommendations of mounting the fuel pumps on the engine side of the firewall.  (I have followed Mr. Eggenfellner's original recommendation of mounting the pumps in the tunnel between the pilot and passenger.)  After insulating the pumps in an aluminum box supplied with a blast tube, the vapor lock issue has been resolved for the other builder.

Knowing that the RV-12's tunnel absorbs a lot of heat from the engine, I took the precaution of installing a 200 CFM computer fan on the face panel of the tunnel to aid in pushing cool cabin air through the tunnel, in an attempt to keep those pumps nice and cool.  The poor quality of ethanol-based auto fuel results in a low boiling point, so vapor lock is a real possibility.

First picture below shows the installed fan in the face plate.

Another view of the backside of the installation.  The fan might be a bit of overkill for the intended task, as it pulls a hefty 2 amps.  I will monitor the fuel pumps temperature to see if I can downsize the fan.

The last installment of this blog will address a problem I experienced with my Dynon Skyview EFIS.  See the picture below.

This is a screen you don't really want to see.  It shows that the EFIS has self diagnosed a recurring problem, which it identifies as a System Event 5.  Apparently when the solid state hard drive inside the EFIS experiences a larger than usual (whatever that means) number of read/write errors, it is time to replace the unit.  To their credit, Dynon had me ship the unit (on my nickel) back to them for warranty repair at no cost.  I lost almost two weeks in the process, but I would hope that I have a newer, more reliable hard drive in the EFIS.

 Lastly, I'll toss in a few teaser shots of N79AM after final rigging and ready for some taxi tests.

Wing Tank and Skins - Final Installation

Finally after all of the hullabaloo associated with the wing tanks and their plumbing...and testing, it was time to wrap it all up.

The following shots are of the right wing's root bay with the vent and fuel lines installed and hooked up.  The skin is lifted up to reveal the plumbing.

The next picture shows the fuselage vent line termination as it runs aft to the belly vent.  This picture is of the passenger side.  You can also see the protruding standpipe.  Note the gray colored support bracket that was associated with the previous fuselage vent plumbing.  It was removed as it was not needed in the modified (and final) version of the fuselage vent system.

A final view of the vent and fuel line plumbing of the right wing, fully seated, prior to skinning the wing.

One final picture, showing a late modification, namely the olive drab colored tube near the bottom.  There was a slight tendency for the fuel line to lift when the excess fuel line was retracted into the root wing bay as the wing was seated against the fuselage.  This simple tube was installed between the ribs to retain the slight downward slope of the fuel line upon final installation of the wing to the fuselage.

One last picture, I promise, of the right wing and its plumbing.  Seen here are the quick disconnect fittings and the clearance available to accomplish removal/installation.  Quite happy with the way it came out.

As the wing skinning process began, service bulletin 14-11-03, was accomplished, as denoted below.

Yours truly popping one of a few rivets in the lower wing skin.

One section at a time with lots of cleco's to remove any twist/distortion to the skins so the matched holes align perfectly.  Lots of fun.

Family affair...here the older son home from grad school over Christmas break renews acquaintances with N79AM.

More family times with son #2 home from Aggieland over Christmas break...the brain trust hard at work.

The access panel adjacent to the wing tip, in the last wing bay.  Ease of access to all fittings of the wing tanks and interconnect plumbing near the filler neck.

Time to flip it over and work the top skins....

An almost finished product.  Wing tip comes next.

 

 The wing tip going into place.

 

A good shot of the wing tip access panel showing ease of service of any fitting associated with the wing tank filler neck.

The left wing has the pitot tube, angle of attack plumbing and the stall warner assembly.  Below is a shot of the externals mounted on the underside leading edge of the wing.

And next, a shot of the internals.  Pitot mast on the left with the clear tubing (transitioning to the green tubing), then the dab of high strength silicone attaching the green tubing to the angle of attack probe (an oversize blind rivet with shank removed) and finally, the stall warner attached to the rib on the right....all flanked by the wing access panel.

Next big milestone was the fitting of the wings to the fuselage.  Shown below are shots of the right wing going into the fuselage for the first time.  A couple of trim cuts to remove slight interference and we were home free.  No big deal fitting one wing at a time...it became a big deal when both were going in together though.

Not a great picture for all the drama required to get the left wing to seat properly.  I had to resort to some ratcheting straps to get sufficient compression on the wing to fit into the bushings.  Also used a Harbor Freight muffler expansion tool to aid in the process.  In the end, with sufficient silicone grease, the spar pins went quite nicely into the bushings.

Use a ratcheting strap from the roll bar to the wing tip and another from the wing tie down ring to the landing gear leg and start the balanced ratcheting.  When you're close, just apply a little pressure from the muffler expansion tool to the spar pin bushing, remove it, add a bit of grease and insert the spar pins - good to go!  Took about an hour.

The end result - first wing fitting!  A site for sore eyes.

 

What could be better than a "blessing of the fleet" from  your loved ones?  I'll carry these notes (on the interior wing skins) of well wishes with me wherever I fly.

Wing Tank Vent System Changed!

If you've been following along with the wing tank installation series, be forewarned that the previously documented fuselage portion of the wing tank vent system has been changed significantly. There was something that was unsettling me about the complexity of the vent system that I could not readily identify.  The plumbing just had to be simplified.  My RV-12 building buddy near Austin, Texas had the trick.

He had located the belly vents aft of the baggage bulkhead, which had the tremendous benefit of eliminating one of the two interconnect vent lines.  Once I saw it, I was all in.  It was such a simple upgrade!  Thanks Dick.

 Below is a reasonable overview of the fuselage vent system.  Of particular note are the partial sheets of aluminum jigged into place where the tailcone will eventually be attached to the forward fuselage.  This jigging was set up to locate the external mounting of the belly vents and siphon break exit.  A similar jig is seen in the upper right portion of the photo which details the location of the siphon break.

This is a close up from the side at tailcone floor level of the vent line as it exits the fuselage.

 Next, is a close up view of the cross over vent line which connects the two vents to one another.

The siphon break line exits through an aluminum bung with an AN fitting....again, through the top of the tailcone.  This shot just shows the tailcone on the floor of the shop.

Shown below is a poor quality picture of the screen covering the opening of the siphon break line on the tailcone.

Next is a shot of one of the externally mounted belly vents on the tailcone.

Once the tailcone was mounted, the plumbing associated with the belly vents and siphon break was secured to the skin of the tailcone.  Shown below is the passenger side belly vent plumbing.

 Also on the passenger side is the plumbing associated with the siphon break.

 That should about do it for the final configuration of the fuselage vent system....and I am quite pleased with it.