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Nice review. Where's the pictures? We all like pictures Thinking of doing Garmin too.
Sent from my iPhone
> On Feb 24, 2014, at 6:24, N20087 <n20087@yahoo.com> wrote:
>
> Folks
>
> I thought I might share my experience with my avionics upgrade in my 360. I decided to remove my Stec 55, sandel HSI and king remote gyro sell it all and install the g3x system. I got 5k and change for the TSOed stuff and then tossed in 2k for the g3x with external autopilot control and 2 servos for pitch and roll.
>
> I chose the g3x for various reasons including the following
>
> I have a good deal of time behind the G1000 a lot and very used to the user interface
> I think the gfc 700 is the best ga autopilot out there and the g3x shares a lot of its technology
> I already had 2 GNS 430s in my panel along with a Garmin transponder. I expected the interfacing to work reliably on the same brand equipment
> Garmin documentation is fantastic, complete and accurate
> I have found Garmin support to be top notch as I am sure the other brands are but I did not want finger pointing between vendors when dealing with integration of components; I wanted just one neck to ring
>
>
> The entire removal and install took 3 weeks from engine shutdown to first flight. Since I work full time this was a weekends and evening activity. A word to the wise, don't do this kind of thing in a cold hanger in the depths of winter. Ask me how I know!
>
> Pointers for others thinking of using this product
>
>
> There is some wiggle room on system pricing with the dealers
> Make sure you check lead times on all parts and get a delivery commitment as part of the deal
> Make sure you inventory EVERYTHING on receipt. You may have to ask your dealer to make good on some missing items
> The quality of the Garmin connectors/backshells is exceptional but they are expensive. Don't accept substitutions. Garmin backshells are heavy aluminum with a unique grounding bar that makes terminations easier and very effective
> Use a spreadsheet to map out your cable schedule with pin numbers and wire colour for each connector
> Buy a quality wire stripper, the kind that grabs the cable and then rips tefzel down to the shield and then individual cores
> I standardized on 22awg all round even though 24awg can be used in many interconnects
> 22awg strips more reliably and does better with crimps
> The connector kits come with quality machined d-sub pins/sockets, you will need to buy more because you will screw up
> Invest in a quality pin compression tool
> You will use a lot of zip ties for mocking things up - buy lots
> Test your cables as you make them and make sure none of the cores are shorted to the shield
> Map out your panel using a cad tool (autocad has a free 1 month eval) and the dxf files for cutouts that Garmin provide
> You can take your aircraft AL sheet and final panel layout dxf file to your local laser/water jet cutter to make the replacement sections. Note 2024 aluminum needs a larger bending radius than shops are used to doing.
> You must purchase a gps antenna that connects to the pfd to use the synthetic vision feature
>
> Once you wire up the PFD, ADAHRS and OAT sensor exactly per the manual you can test the bare bones system.
> You must follow the magnetometer calibration procedure to the letter.
> The system uses CAN bus for communications. This technology requires terminations on each end. I terminated at the PFD and at the pitch servo
> The servo mounting kits are pretty decent and complete but in the end I repurposed what I already had which needed little modification
> The magnetometer interference test is very useful in determining the installation position. The sensor is mounted to one side of the hat rack below the floor. My tests passed for all electrical devices except the pitch servo clutch engagement. It was over by a max of 20%. In speaking to Garmin I might get away with it. Having flown a few times now and using the ap there have been no ill effects i.e. Bad headings or red Xs.
> I did not jack the aircraft as suggested by Garmin to verify interference effects of the hydraulic pump since my pump is mounted on the inside of the firewall.
> The capstan servo kit does not include mounting brackets
> You will need to make your own pitch servo bridle if you are using a capstan scheme
> I did not connect the auto trim system as I figured I would do this later
> Even in a 360, there is a need to adjust pitch trim when changing speeds significantly with the ap engaged
> if you use Garmin transponders make sure the firmware is up to date to ensure the RS232 connection to the ADAHRS works correctly
> Make sure the autopilot servos are set to operate in the right direction on the ground otherwise things could get interesting really fast in the air. In my case I had to reset the direction from the normal out of the box direction, all a function of your mechanical mounting arrangement
>
> So how does it fly? In a word, excellent!
>
> The PFD screen really is big enough for a 360. The user interface is more intuitive than the G1000.
> Very few integration headaches, just follow the Garmin directions
> The highway in the sky feature along with the flight director and flight path marker is really neat. But beware it can really dumb down your instrument scan
> The screen is plenty bright in sun
> Tuning the auto pilot took about 10 minutes of tweaking the gains. The default torque values are pretty close already
> Flying a coupled LPV approach is just amazing, it behaved flawlessly without much fuss even on a slightly bumpy day with a 12 kt x wind component. The system flew an order of magnitude more smoothly and accurately than the original Stec 55. The integration ith the GNS430W is very well done. I really did not have to change how I did things (buttonology) to fly an approach relative to the sandel but the presentation on the HSI is far better
> Indicated air speed climb is quite usefull but should only be used in relatively smooth conditions as you will find the AP sawing on the controls. It does a good job maintaining air speed, better than I ever could but I think it is too hard on the controls. Sometimes you just have to hand fly!
> Vertical speed climb is better damped but you would need to be on top of changing the desired rate as performance bumps up against the edge of the envelope
> The up/down thumb wheel on the AP is really cool and handy
> The default setting for sink rate Alarm is not consistent with Lancairs.
>
>
> Things yet to do
>
> Install the Garmin AOA pitot
> Install ADSB receiver for WX
> Fix bitching Betty
> fly more!
>
> Tom
> Lnc2 312 hrs
>
>
>
>
> --
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