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Ironflight
12-08-2009, 05:24 PM
It is VERY dangerous to talk to Lucas at Tru Trak on the phone – everyone needs to know that! I was chatting with him a month or two back about a problem we were having with Louise’s ADI (rapidly corrected by TT), and mentioned that I had lost an LED segment on my Pictorial Pilot, and would have to get that in to him when I had the time. Long pause…..”Paul, you’re still flying with a Pictorial Pilot? And you have GRT HX displays?! You need an upgrade!” Dangerous words, dangerous words….because when I went and looked at the prices, taking into account Tru Trak’s policy of full credit for traded in equipment, the leap from the PP and Altrak to a Digiflight II VSGV was nowhere near as much as I expected. That actually brought his suggestion in to the realm of possibility, and after a month of searching the budget, I found that I couldn’t resist. So I pulled the trigger and decided to do the upgrade at the same time I was installing a Dual AHRS in my GRT EFIS and doing the Condition Inspection. I knew I’d need to add some wires to the back, and there is no better time than when everything is opened up for inspection.

The PP/Altrak Combo has given me great service, providing me with altitude hold, heading hold, and Nav Tracking capability. The fact that the autopilot gave me a redundant attitude source played well with my redundancy scheme for IFR flight. Originally, I settle on the Pictorial Pilot because it included a turn rate display that would allow me to fly partial panel should the EFIS quit – but it didn’t take long for me to realize that in that case, I’d just engage the autopilot to keep the wings level and make turns, so the display wasn’t that significant. Going with the VSGV, I’d be giving up that familiar face, but I’d be gaining GPSS capability so that the EFIS could drive the autopilot to make predicted course intercepts and fly fully coupled approaches. In addition, the ability to digitally select altitude rates is very attractive when managing a descent from altitude in a slippery RV. And altitude pre-select is an added bonus for single-pilot IFR in an RV that can climb or descend at 2,000 fpm. I didn’t truly NEED these capabilities, but they sure would be nice to have since the price was right.

The swap was pretty simple from the standpoint of what I needed from Tru Trak. Lucas only had to send me a new panel unit (the brains and controls of the autopilot) and a new pitch servo. My Altrak’s pitch servo didn’t have trim sensing, and the Digiflight requires it – otherwise, the two servos are identical and fit the same bracket. Unfortunately, this means I needed one additional wire to the back of the airplane, and that added some time to the installation – but since I was combining the job with the GRT upgrade which needed new wires to the back for the magnetometer, it wasn’t a big delta. After the installation, I just needed to send my old Pictorial Pilot, Altrak control box, and pitch servo back to Tru Trak to complete the trade – oh, and a credit card number, of course. (When I actually got in to the installation, I realized that I really didn’t have a servo cable running from the panel to the back end, since my Altrak brain box was back by the servo – only control and indicator lights ran forward. But Steinair sells a pre-twisted servo cable “by the foot”, and that made the job much quicker.)

Once the new pitch servo wires and servo were in place, the rest of the action was up at the instrument panel. I disassembled the old Pictorial Pilot and Altrak connectors, and labeled each conductor with it’s function. It helped that all the existing wires had D-sub sockets already installed, and that’s what they needed, so about half of the job was simply unpinning the old connector body. I built a table of conductors that showed where each wire (connector and pin) came from in the old setup, and where it was to go on the new digitrack connector. Masking tape flags on the wires with pin numbers and functions written on them kept the memorization to a minimum. When I had all of the necessary conductors found and labeled, it was a simple matter of re-pinning the new connector body, and I was on my way.

In the “New conductor” category, I had to find the ARINC lines from my existing GNS 430 and EFIS bundles, and extend them through a DPDT switch to the autopilot. There are six ARINC lines on the GNS 430 pin-outs, and I actually surprised myself to find that five years ago (when I wired the plane), I put pins and wires into the connector for these, and left them bundled behind the panel! This made it a simple job to splice in what I needed to complete the schematics. It really helped that GRT has a drawing which shows all of the interconnects for a GRT/Garmin/Digitrak installation – that almost takes all the fun out of it (but sure eliminates mistakes induced by misinterpretation of the drawings. To prevent disappointment during initial smoke testing, I have a discipline of checking where each wire come from and goes to at least three times while the bundles are still open. Mistakes still happen, but this eliminates most re-work later on.

Speaking of initial smoke testing, I was very satisfied (when power was applied) to find that no replacement smoke will be required – it all stayed in the wires and boxes, where it belonged. Replacement smoke is VERY expensive, and you never want to have to buy any! In this case, the system powered up and I stepped through the initial ground testing very quickly, with all boxes checked off. I had to snip the wires on my “pitch servo reversal loop” (pins 1 &2 of the Digitrack harness are connected with a loop – if the pitch servo drives backwards, you snip it, and open the circuit), but other than that, the checkout was without error.

Flight testing is in the near future (winter weather seems to have found Houston), and I’ll report on how that goes. It should be fun learning all the new capabilities. We’ll see how many surprises I get in good VFR conditions before launching into the clouds…

Paul

Brantel
12-08-2009, 05:38 PM
Geez Paul, slow down spending all that money! Did'nt you know we are in a recession? :D

Your gonna have to learn how to fly that thing all over again with all them new toys! :p

Rick S.
12-08-2009, 05:38 PM
I know what you mean...I've stared at the phone thinking it's only $XXXX.XX to turn in the RV-10 AP for the Sorcerer..."This is not the auto pilot you are looking for" "You don't need those few more functions" Well after playing a little IFR lately...I want those functions just cause, the RV-10 filled all the needs so far.. I've resisted the dark side for now..but what a great upgrade policy!!

rleffler
12-08-2009, 06:13 PM
I know what you mean...I've stared at the phone thinking it's only $XXXX.XX to turn in the RV-10 AP for the Sorcerer..."This is not the auto pilot you are looking for" "You don't need those few more functions" Well after playing a little IFR lately...I want those functions just cause, the RV-10 filled all the needs so far.. I've resisted the dark side for now..but what a great upgrade policy!!

I'm sure you know that the Sourcerer has a 15% discount at the moment. It makes that delta smaller. Hmmm, I wonder what Rick will buy himself for Christmas.

scard
12-08-2009, 06:18 PM
Ah, glad to see you're finally coming up to the capability that we've been enjoying for over two years now. You're going to love it.

Rick S.
12-08-2009, 06:31 PM
I'm sure you know that the Sourcerer has a 15% discount at the moment. It makes that delta smaller. Hmmm, I wonder what Rick will buy himself for Christmas.

Yeah, thanks Bob:rolleyes:, Stein already told me I have an $11.86 credit:) I can use towards it...All I want for Christmas this year our men and women serving to just serve, not die, for me personally I already have the best gift, Family, Friends, Health and a really cool airplane...but if it were possible...
100LL to go back to $1.85...and maybe someone to ask me to coddle one of these fine machines together for them...That's a joy, building these fine machines.:D

Kyle Boatright
12-08-2009, 07:08 PM
Geez Paul, slow down spending all that money! Did'nt you know we are in a recession? :D



With the end of the Shuttle program, NASA is just giving the leftover funding to Paul...

Ironflight
12-08-2009, 08:49 PM
With the end of the Shuttle program, NASA is just giving the leftover funding to Paul...

If I could keep the Shuttle program funded by donating the funds.....:rolleyes:

Capflyer
12-09-2009, 04:38 AM
For all the IFR flying you do, then next time you take off in 0/0 and only need to push three buttons and let go of the stick, you'll wonder why it took so long to upgrade. The GRT's work great with the VSGV, just set up your rate of climb or climb airspeed and desired altitude before taking off and you're set to go. No need to ever touch the AP again until you turn it off on short final. You're gonna love it.

TrutrakTech
12-09-2009, 07:39 AM
Paul, it's always good to see the magic smoke staying inside the box. ;)

Rick S. Call me, we should talk... :)

Veetail88
12-09-2009, 10:26 AM
Rick, I smell "an offer you can't refuse" coming!:eek:

Rick S.
12-09-2009, 11:11 AM
Hmmm...I may have to call..maybe a scratch and dent sale? How come when we get a great deal on an airplane part:) it's not as accepted a well as the dress that was only $250:eek: but she saved $300 so you CAN'T let a deal like that go!:D:rolleyes:

rv7boy
12-09-2009, 11:34 AM
Paul,

I am visualizing you putting together a series of videos showing us newbies how to install and upgrade the avionics in our RV's. Sorta like the EAA How-to videos. Doug could make it as well as other topics one of the regular features of these forums. I think of avionics first, but there are other topics too that you could show. Even a simple video of converting a bundle of wire-tied wires to a laced bundle would be interesting. Whadduya think?

I know you are real busy right now, but with Louise helping, it would be a fantastic opportunity to share your knowledge.

Hope you seriously consider it.

the_other_dougreeves
12-09-2009, 12:09 PM
We upgraded from a 1-axis 2.25" pictorial pilot to a 2-axis 3" ADI Pilot II and like the results. We were very happy with the trade-in policy. Thumbs up for TT.

TODR

Ironflight
12-09-2009, 05:32 PM
I?ll tell you ? these modern avionics are wonders of technology ? not only do amazing things, but if you take just a little care in installation, they work right out of the box! I took off this morning into the first clear skies we?ve seen in five days to do the initial testing of both my GRT Dual AHRS installation and the new Tru Trak Digiflight VSGV autopilot.

My test card called for a normal take-off and sortie to the test area, out from under the class B ? no testing of the autopilot until I had sufficient altitude and room to maneuver, and no playing with the EFIS while still in the traffic pattern. As it turned out there was little to play with on the EFIS ? the indicators showed both AHRS to be doing just fine, and I essentially had no operational difference between the new and the old. Everything worked as advertised, just as all my GRT equipment has done. Since I had also upgraded my lower Display Unit from an HS to an HX, I found myself leaving the map up down there - it sure looked nice!

Once I had sufficient altitude and had cleared the area, I engaged the autopilot in heading mode to see how it did. The results were spectacularly boring ? it worked just as advertised. I turned the knob to initiate turns in both directions, and was pleased to see the airplane respond at just about standard rate ? the older Pictorial Pilot never turned faster than half standard rate, which made hand flying mandatory when changing heading for vectors in a terminal airspace. Next came altitude hold ? and that worked just as well as the old AlTrak that was being replaced. The controls are well thought out and fairly intuitive ? not bad for three buttons and a knob. The first new thing I tried came next ? coupled climbs and descents, and I was pleased to see the airplane respond as I dialed in a rate of climb. Descent worked just as well.

With the initial curiosity quenched, I pulled out the Tru Trak ?first flight? checklist, and ran though through it quickly to see if there was anything I needed to set before trying to couple the autopilot to the EFIS. Most of the parameters looked just fine at their initial values, and it was a piece of cake to scroll through the setup while flying along at altitude. My next step was to punch up the GPSS mode, which would couple the Autopilot to the EFIS, and see how it was to fly from the big screens. I put the EFIS autopilot control in ?Heading? mode, dialed the bug to match my current path, and engaged. Again ? the wonder was in what DIDN?T happen. We tracked right along. Now I could dial in heading changes on the moving map and the airplane responded with nice standard rate turns. Pushing the ?ALT? button on the Tru Trak next engaged the GPSV mode, and the autopilot was flying altitude controlled by the EFIS, and things REALLY got nice. For years, I have selected altitudes on the GRT EFIS to use as a reminder upon reaching them to level of. Now the airplane responded to the altitudes all on its own. Climb and maintain 5,000?? No problem! Set it and watch it. The only problem I experienced was some ?hunting? in pitch, which GRT says I can tune out with some settings on the EFIS page ? that will be the next flight!

The next and last thing I tried on this first flight was a coupled approach. Since our usual ILS runway seemed to be engulfed in a cloud back this morning, I dialed in a GPS approach to our neighboring field on the 430. I armed the GRT Synthetic Approach, and it slaved to the 430?s approach and runway selection. I engaged the autopilot and dialed in a few altitudes to remain underneath our local Class B, and watched the show. The turn anticipation was impressive, especially since I really haven?t tuned the gains for the RV-8 yet ? we never overshot, and hit every new course about where I would have if I was hand flying. Even the 90 degree turn from base to final was smooth. The autopilot/EFIS kept the velocity vector circle directly in the middle of the Highway in the Sky boxes all the way, despite a gusty crosswind of about 20 knots. I am still a bit skeptical about flying all my approaches coupled, as I like to hand fly rather than figure out what the avionics might do at the next point in the approach (will it hold? Do a Procedure turn? Or maybe a straight in?..), but that?s me learning the system a little more rigorously.

Overall, with one test flight in the bag, I am quite happy with the upgrade.. Everything works as promised, and with a little fine tuning ? and a lot of procedural practice ? the capabilities will help to reduce workload. It is simply amazing how far we have come in the experimental avionics world in a very short number of years. I am impressed with the cooperation between the various vendors, and I don?t just mean GRT and Tru Trak ? they are all building off one another competitively as well as cooperating sufficiently to allow integrated operations between their systems. In fact, I think that cooperation is going to be the key to success in the long run ? the more your gear works with someone else?s, the larger market share you can hope to achieve!

Paul

Ironflight
12-09-2009, 05:48 PM
Paul,

I am visualizing you putting together a series of videos showing us newbies how to install and upgrade the avionics in our RV's. Sorta like the EAA How-to videos. Doug could make it as well as other topics one of the regular features of these forums. I think of avionics first, but there are other topics too that you could show. Even a simple video of converting a bundle of wire-tied wires to a laced bundle would be interesting. Whadduya think?

I know you are real busy right now, but with Louise helping, it would be a fantastic opportunity to share your knowledge.

Hope you seriously consider it.

I am flattered by the suggestion Don, but right now, the old saying applies "Build an Airplane, not a Web Site....." So many irons in the fire these days....

rv7boy
12-10-2009, 10:18 AM
OK, Paul, but just keep those posts going. I guess you have a good excuse since you have two RV's to maintain and one to build, in partnership with Louise, of course.

Your posts here will help many of us over some hurdles down the line. But at the rate I'm building (wings) there will be a new generation of avionics by the time I get ready to start running wire!

Thanks for your contributions here.