Going Backwards?!

In the interest of maintaining a Viking engine with all of the up-to-date enhancements and upgrades, I found it necessary to get on the list for a new oil tank and flywheel.  Early adopters, like myself, to a relatively new alternative aircraft engine are subject to such things.  So here's what we've got:

1. An upgraded oil tank that is now a welded unit, as opposed to the original that is bolted and siliconed together.  On top of the inherent strength and tighter fit, the new unit features an improved filler neck and dipstick tube.  But the real draw for me is the bung that is now welded in place to receive the engine oil line and fitting that returns oil from the PSRU!  The Viking engine has another port that ties into an oil galley on the block from which high pressure oil is routed to the PSRU.  Instead of a small quantity of 90 weight gear oil (about 3 ounces), the PSRU will be supplied with a constant supply of circulating engine oil.

2. A new, slightly heavier flywheel made out of steel, replaces the second generation aluminum model that has been prone to the development of cracks.

In order for all this to come to pass, it was necessary to remove the old flywheel/ring gear assembly and the PSRU and return them to the factory.  The ring gear gets reused, but the old flywheel goes away.  The PSRU has a sleeve pressed onto the drive shaft.  Yet another issue to be resolved was the removal of the pilot bearing from the crankshaft....more about that later.  In its place will be a brass ring.

First in the process was the draining of the engine oil and then the coolant from the radiator and hoses.  Radiator is now detached, with only the rear bracket remaining.  Cross over tube was completely removed as well.

 And there she lies, draining the last drops of the Evans NPG coolant into my oil change pan.

Up next was the oil tank removal.  The unit is bolted together with a long bolt that runs from the top to the bottom of the tank.  Even after removal of the bolt, the work is just beginning.  Breaking the seal of the Right Stuff silicone was a huge chore.  I was in disbelief at the strength of that stuff and its ability to hold aluminum parts together.  In the end, it was the use of a pry bar (no less) that was required to carefully separate the tank bottom from the body.  After removal of all but one of the 16 M8 allen bolts holding the tank top to the bottom of the engine, it was time to pry again.  This time the old oil recirculation bung was used with the pry bar and the block of the engine to break the tank body from the tank top.

The shot below is looking from the ground up and shows the bung on the tank body that was pryed against for removal.  Once you had the pry bar in place, (between the bung and the engine block) the silicone was relatively easy to break...but when you realize the leveraged force required to do so, it leaves me with a great respect for the strength of that silicone product.

 With the radiator and oil tank removed, it was time to turn my attention to the removal of the PSRU.  Unfortunately, I did not get any shots of the removal process.  Below is a picture of the tapered 2x4 that I carefully used to pry the PSRU away from the engine block after the 4 large bolts were removed.  It was really quite easy to slide it off the engine with just a slight bit of encouragement.

With the PSRU gone, the rubbers or vibration dampening doughnuts and spider gear are clearly visible on the flywheel.

Six nuts removed and the spider gear/doughnut assembly comes away nicely, leaving the final 6 flywheel bolts.

Close ups of the spider gear and rubber doughnuts are shown below.

To get the necessary torque on the flywheel bolts, a simple locking mechanism was employed to restrict crankshaft rotation.

Bolts are out...

...and off comes the generation 2 flywheel and ring gear.

And there is the next target - the smallish blue ring: the pilot bearing.

I have to say that pulling that bearing was fun!  No kidding.  I googled up a few youtube videos about guys using everything from axle grease to a piece of bread to strips of water-soaked paper to use hydraulic pressure to remove bearings.  So that's what I did.  The water/paper trick looked to be the neatest and simplest, so that is what I tried.

 Start with some paper soaked in some water and then start stuffing them into the bore of the bearing as shown in the first two photos below.

 Next up, begin "plunging" a shaft (in my case, a 7/16 nut driver, whose OD just matched the ID of the bearing) with the aid of a hammer or mallet and compressing the soaked paper shreds.  As you penetrate deeper with the shaft, remove it and replace with more soaked paper shreds.  Rinse and repeat.

Before too long, you end up with the bearing slowly peaking out from and then entirely protruding from the bore!  Works like magic!

Lastly, pry out the soaked paper and you are done.  Unbelievable - but I'm easily impressed.

Before I close this tome, I'll make mention of another implication of the upgraded oil tank....and it is not a minor one.  The new oil tank will require me to relocate the oil cooler to a location lower on the firewall to insure clearance for the PSRU oil return line.  That consideration, combined with the fact that the new tank changed the location of the filler neck and dipstick tube and there are wholesale changes that have to be made to my upper and lower fiberglass cowls!!!!!!!!!

Specifically, the oil cooler duct will be relocated to the lower cowl.  The first 2 shots below, show the amputated oil cooler duct and the foam filler patch, awaiting its new glass cloth and resin.

Inside view of former location of oil cooler duct.

Sanded, cleaned, glassed and peel ply'ed and it will be ready for finish sanding/filling to make it seem like a distant memory.

Next the lower cowl has been cut to facilitate the new lower position of the oil cooler duct.

Front view of the cooler duct's new location.

 The upper cowl not only lost the oil cooler duct, but the oil access hatch door will have to be relocated too.  First shot below shows the inside with the foam patch awaiting shaping to the original shape of the cowl.

Outside view of same.

And the saga continues....

Finally, both of the patches are glassed from the inside as well, to insure structural integrity of the cowl.

Next installment will begin the reversal of this "going backwards" process as the upgraded parts are due in tomorrow, so stay tuned.  There will be plenty of perils on the way toward achieving the engine oiling of the PSRU....not to mention the new oil cooler duct in the lower cowl and the relocated oil access door on the upper cowl.

Skyview Avionics Installation, Part 3

With the first engine start under my belt.  It was now time to finalize the engine monitoring system (EMS) wiring so I could monitor the engine during runs.

The first step was to thoroughly pour over Van's RV-12 schematic that shows the entire Van's Skyview system.  I purposely refer to it as Van's as opposed to Dynon's because of the AV-50000A Control Module, shown below, in the lower left hand corner of the photo.

This magical black box acts as the termination for all of the Skyview harnesses running from all of the various components: EMS, Transponder, Comm, Switch & Fuse Panel, Autopilot servos, just to name a few.  Without a very detailed tracing of wires through the maze of the Control Module, one is quite lost as to where things go and what they do....even WITH a very detailed analysis, it remains a daunting task.  Never the less, I persevered and sought out several other opinions of those with more experience than myself and finally arrived with the 10 or so wires that now make up my Viking Firewall Forward wiring harness.  This replaces the Firewall Forward wire harness that Van's ships with their Rotax 912 Engine package.

The two picture below show the 25 pin dsub connector for the Viking Firewall Forward wiring harness.

Now its time to start plugging the high dollar electrowizzes (I believe that's what Bob Nuckolls calls them.) into their respective instrument panel holes and finish up the initial wiring of what's available....without an aircraft tailcone and the ADAHRS unit. 

Time for the first power up and this is what I saw...

 ...and this...

After some reading in the Dynon Installation manual, I was able to go to a full EMS screen and start configuring engine sensors.  The user interface is delightful.

A rather poor close up of the instruments...

 After a couple of calls to Dynon for a couple of problems (no ADS-B transceiver showing up - the result of an incomplete crimp on a splice), I was able to find the EFIS and EMS components on the network as well as 4 of the 5 serial devices (the ELT was not yet wired up), so I think that I am good to go!

The ELT wiring was next and consisted of running four 20 or 22 AWG wires into a very tiny din connector.  Instead of soldering the wires, I opted to crimp female dsub pins that I could then slide onto the ends of the posts of the tiny din connector (not shown).

The next picture shows the 4 pins that have been slid onto the posts of the din connector. 

Following the directions, I proceeded to "pot" the back side of the connector with the female dsub pins with a glob of silicone.  Another boot was slid up the back side of the din connector and again potted with more silicone and the female assembly is ready for its male counter part that runs from the ELT.

First Engine Start

Well, there was an onerous beginning to this short saga....and no photographic evidence either, as I failed to follow through with all of the busyness of the engine's initial ops.  My first attempt at the start up resulted in a brief but intense shower of high pressure gas spewing from the fuel line that connects the fuel flow transducer to the flared AN fitting on the firewall shelf.

After safely shutting everything down, I drained the 5 gallons of fuel and removed the offending fuel line from its two end fittings.  What I found was that the fuel line's flared end had cracked, I would surmise due to work hardening or some such negligence on my part during the installation.  It was probably 1/16 - 3/32 inches too short in length as well.

At this humbling juncture, I made some more measurements and contacted Tom Swearengen of TS Flightlines and had him manufacture a braided steel, teflon lined unit for me.  So no more stinking aluminum flared fittings made by my hands!  Everything now in the high pressure portion (downstream of the fuel pumps) of my fuel system is steel (with the exception of a couple of fittings on the fuel filter and the body of the fuel filter itself).  I feel much better now about the integrity of the fuel system.

The short clip of the first start up is posted below.  There is a lot of background noise prior to the first start: a landscaping crew at work across the street and my large pedestal fan behind me running at full blast.  Also, I managed to shoot the video in a portrait orientation, so just tilt your head for the full effect. :-)

To say the Viking engine is smooth is an understatement.  It is a thing of beauty to behold when running.  Granted I have not run it up to any significant RPM yet, but if idle is any indication, it will be a real treat at the higher speeds.

Canopy Closure Switch

Apparently there have been a handful of incidents with pilots getting distracted after being airborne only to discover that their canopy is not latched.  There have been crashes....supposedly all in the guise of a distracted pilot.  Purportedly, the RV-12 flies just fine with the canopy unlatched and there is no propensity for it to depart the airframe in flight.  The fact remains that it has apparently been a signficant safety issue.

To this end, Van's engineered a canopy latching switch, which will serve notice to the pilot by a signal/notification to the EFIS of the problem. As I understand it, if the switch (and thus the canopy) is not locked, then once the engine reaches 3700 rpm, the EFIS will display some info informing the pilot of the condition.

The picture below contrasts the original canopy latch, shown on the left with the new one on the right.  You will note the small micro switch above the latch on the right, which will eventually be mounted on the face of the latch.

Another wire (the white one) was required to be strung from one of the wiring harnesses terminating in the instrument panel all the way back to the roll bar, where it exits at the underside of the center as shown below.  The other two wires will interface with the cockpit light.  Also of note is the nylon latch stop, which was also swapped out with the original unit.  No pictures of those.

Shown below is a picture of the canopy latch switch mounted to the "hook" which is then riveted to the back side of the roll bar, just as the original.  Of further note is the small ground wire mounted above and the right of the canopy micro switch.

This shot shows the canopy latch handle engaging the arm of the canopy latch micro switch - this is what we are after.

And a final shot showing the canopy micro switch NOT fully engaged - this is one of the circumstances which we are trying to avoid!  Looks like mission accomplished.

Skyview Avionics Installation, Part 2

The avionics install is continuing to progress very slowly with the power distribution layout almost complete.

In the picture below, you can see the power bus (mounted above the ADS-B transceiver) with its two independent feeds - from the battery only on the nearside and the alternator on the far side.  Immediately to the right of the power bus is the 6 fuse block mounted into the top of the center instrument panel.

And the pictures below show the same set up from other angles.

Of interest below is the ignition/start switch panel, in the lower left hand corner of the instrument panel. The two wider rocker switches at the top are the Master switches.  The switch on the left actually doubles as a start enable and a battery (only) master switch.  The switch on the right is the more conventional alternator master switch.  The two masters are there for redundancy such that the power bus can be independently powered by either one.  The battery master switch doubles as a start enable switch so that the starter cannot be unintentionally activated when the engine is running.  This was a necessity as the engine start switch is on the index button of the pilot's control grip.  You can imagine the fun that Murphy would have with that.  The start enable switch is also there to prevent starter current from running through the power bus and destroying component in the unlikely event of a battery contactor failure.

The second tier of three rocker switches are, from left to right, the ECU selector switch (either computer 1 or computer 2), fuel pump 1 and fuel pump 2.  So there you have it - the ignition panel of the Viking engine.

 

There is a rat's nest of wires that is already forming behind that switch panel....and its not yet complete.  See the lower portion of the picture below.  You will note the primer missing around the four holes on the instrument panel deck - this is where the Van's AV-50000A control module picks up ground from its mounting screws.

It is now time to plumb the manifold pressure input lines to the ECU. A couple of snips and the norprene lines are slipped on to the barbed fittings of the ECU.

As dictated by the power distribution wiring schematic (not shown), a secondary fuse panel was required.  This was mainly due to some of the differences between the Viking fuel injected engine and the Rotax carbureted engine.  In the shot below, the five fuses are for the ECU power, the two fuel pumps, the start circuit and the heater.  There is one unused slot.

A clearer perspective of the location of the auxiliary fuse panel, located above the comm and the "stock" RV-12 main switch and fuse panel (not yet installed).

As a bit of finality prior to the first engine start, the battery was hooked up to the contactor and grounds and a bit of integrity checking of the power distribution was performed.  All passed (I think) with flying colors.

Next stop on the avionics agenda is the first engine start!!!!!

Skyview Avionics Installation, Part 1

I have to admin to a great deal of trepidation at the outset of the avionics installation.  To put it mildly, electronics has always been a struggle for me.  Much to my surprise (so far at least, which isn't very far), the initial installation tasks have been quite trivial.  The theme would best be described as "plug and play."

There have been some manufacturing requirements of a minor nature and I'll probably spend more time covering those because plugging a connector of a wiring harness into a black box is not too exciting.  With that note, I'll begin with the installation of the skin stiffener of the upper tailcone, where the ADAHARS magic box lives.

The shot below is the stiffener that Van's now includes in the Skyview Avionics subkit.  A number of builders/flyers reported intermittent errors from their EFIS/ADAHRS which were traced to possible excessive vibration of the unit during certain phases of flight.  The stiffener is the prescribed attempt to eliminate these issues.

The next photo shows the stiffener cleco'd into position, after match drilling 17 #30 holes into the skin.  Directly behind the stiffener are the 2 brackets upon which the ADAHRS box will be mounted.  The nylon tubing which dangles from the former, behind the brackets are the pitot and static air lines that will be plumbed into the ADAHRS box.

Here is a picture of the magic black box, aka ADAHRS.

A close up of the unit, plumbed and mounted to the brackets.  The third port of the left, currently fitted with a nylon threaded plug, is for the angle of attack airstream.  Much more on that subject later, when I get to the installation.

 

A final parting shot of the installation showing the former, stiffener and the unit all mounted.  A 9 pin connector mounts to the rear of the ADAHRS box, but will not happen until the time the tailcone is mounted to the forward fuselage section.

Another of the manufacturing tasks to be conducted was a relocation of the GPS antenna tray.  The Viking engine sits considerably closer to the firewall than the Rotax, and that necessitated relocating the GPS antenna.

Below is my much smaller antenna tray that ended up getting mounted on the opposite side of the Engine Monitoring System (EMS) black box on the firewall.

This picture shows the EMS in the upper left hand corner...not shown is the GPS antenna tray.

 

Here is the installation picture of the GPS antenna on its tray on the engine side of the firewall.

 

Next photo is a shot of the Garmin GTR 200 comm radio with its tray, prior to installation.  The tray is the original from Vans, which shipped with a Dyno radio, which is no longer the standard.  Instructions were to verify that the bezel of the Garmin unit still cleared the cut out in the center instrument panel.  Thankfully, it appears to fit just fine....thank you very much.

 

As I mentioned at the outset, this is going to be a relative overview of the avionics installation because of the simplicity involved.  The picture below shows a lot of stuff!  On the far left is the "network interface unit" (NIU, my description) where each of the wiring harnesses terminate.  As previously mentioned, just behind and the right of the NIU, on the firewall is the EMS.  To its right is the gold colored transponder tray.  In front of the transponder tray on the instrument panel shelf is the backup battery.  The backup battery sits just to the left of the Garmin comm tray.  Above the comm tray sits the ADS-B unit.

Shown from the opposite side is another picture which better shows the Viking ECU, which is the red box mounted on top of the map box.  The long black hoses will attach to the two ports, which are currently capped off with a small interconnecting tube.

This shot shows a close up of the ADS-B unit atop the comm tray, looking from the firewall.