A few issues with my Skyview HDX system.

[jaba-who]

Hi All.
I have noticed a few issues and need some advice on them.
I have a Skyview HDX with autopilot, knob panel and autopilot panel, a network hub in a Jabiru. Installed it all a year ago and some issues have been present whole time and other have started more recently. Most are intermittent and not stopping me flying hence the long delay in getting into them.
Problems:
1. Touch Screen error. Been present from beginning but intermittent. Error message in bottom of screen but it seems to come and go. Until recently it said error but everything seemed to actually work. Maybe there was an issue but it didn’t affect me so I ignored it. Lately I have been getting a failure in sensing my finger touch. So some days I have to use the knobs to execute commands and can’t use the map to do navigation commands. But then other flights it works fine again.
2. I recently started getting an intermittent black screen with big Red Cross through it saying ADHARS failure. Lasts only fraction of a second then all comes right without action by me. Everything is back working instantaneously except the timer has dropped back to zero and the autopilot has turned itself off. Started happening every few minutes during flight. I assumed it was a wiring connection error and pulled all the wires apart and cleaned and reconnected them. Problem almost disappeared but still happens maybe once a flight. I still think it’s a wiring connection issue but I’m mostly after advice on honing in on which wire/plug might be the issue to replace or fix it. Since it’s an intermittent fault it’s been impossible to figure which cable or plug is the cause.
3. Error in the winds aloft calculator or display. The winds aloft calculator is way out and need advice on fixing it. It says I have about a 10 knot error in the wind ( ie says 10 knots in zero wind, + 10 above what appears to be the real wind speed) blowing from my right all the time, as soon as it calculates a wind (?even when I have landed and on the roll with aircraft tracking wings level and straight with nil wind it still claims I Have cross wind. Have done the inflight test - flown a box and always the wind seems to be from the aircraft right. Swings around a bit but always a major right component. Flown with another aircraft who has completely different winds aloft on a different device which approximate the area forecasted winds. So I’m convinced it’s in error.
Ive done some reading of the manuals but it doesn’t seem to have any way of calibrating it. All the parameters that it uses ( GPS, airspeed etc) seem to be working accurately.
Any ideas on any of the above.

 

[DBRV10]

Not sure about point 1.

Point 2 is almost certainly a connector issue. Are these SV NET cables yours or Dynon ones? If you can, send the cable from the ADAHRS directly to the screen, and then the screen to the hub. At least then the ADAHRS-Screen is one connection only at each end.

Point 3. This is a long one so stay with me.
a. Is your Pitot tested accurate (it should be)
b. Is your compass accurate, and verified, if not a ground calibration and an inflight calibration is required.
c. Is your static source actually accurate in flight. The only way to verify this is fly at a constant speed, take note of the calculated TAS and do a GPS box to establish the real TAS. if this is in error of more than two knots this needs fixing.
d. Your TAS is temperature affected. So where is your OAT probe? If it is under the belly somewhere, it needs to be moved. It will be exhaust effected. Under the wing root would be OK on a Jab.

Hope that helps.

 

[jaba-who]

Thanks David.
The cables are dynon Cables but as best I recall they only come with one plug on them And installer to attach the other to allow for variation in size requirements. I can’t remember exactly how much if any that ADHARS Cable needed chopping off To fit. but I can probably re-rout it to link it direct to the screen. Good idea. It’ll at least narrow it down.

WRT to the winds aloft issue. The static source is the standard jab one in the tail.
the temp probe is under the wing root. Pitot and static was all intact and checked out on installation. Hasn’t had a formal redo of the AD Rad 47/49 or whatever it’s now called since installation. Did a calibration Of compass during installation ( both on ground and whatever in air was needed) Have to admit I can’t remember what I did in the air Cos I spent ages doing the lot that was needed And it’s all blurred into one now. but do remember the ground calibration and have signed off on the calibration so have to assume I did the lot.
the compass reads pretty close to true just eyeballing it wth runway headings And the old Floating ball version on the dash etc ( part of my run up check list).

might be time to revisit the lot and work through them.

 

[DBRV10]

Yes, revisit and test according to the list I provided.

 

[djones]

....and to expand on David's list, if the wind is always a cross-wind, it is a compass calibration problem. Head or tailwind is a airspeed problem.

 

[jaba-who]

Thanks djones.
yep always a cross wind from the right.

 

[DBRV10]

....and to expand on David's list, if the wind is always a cross-wind, it is a compass calibration problem. Head or tailwind is a airspeed problem.

Absolutely

And just for the record, as Ronald Reagon once said "Trust but Verify". So hence the long list, because you may fix the gross error and then say, yep! I fixed it, but all the other small errors exist.


Question for Jaba-who.......where is the ADAHRS mounted? Sometime compass things are badly affected by currents that come and go, if they are mounted up front. Tail cone is good, as is under the seat. But I had a Jabiru client where he opted for under the seat for the ADAHRS, and that was fine. But when you put an iphone on the seat, not so much.

Trust but verify. Remember Ronnie!

 

[kellym]

Thanks djones.
yep always a cross wind from the right.

Just to amplify, be sure you get a calibration score of greater than 100 for the in-flight calibration. You should see within a couple degrees when lined up on a runway with precise heading (ie the heading shown on an instrument approach plate).