GPS failure

 

Now I had the update installed last week, and the first two flights have resulted in the same problem.Yesterday,  I waited over five minutes while the engine warmed up, and still NO GPS. Again, after restarting, it picked it up. And it held them during the flight.

 

What's up with this? Is is something in the software? Why do I have to restart the unit to capture GPS?

 

Very frustrated at this point.

 

 

 

How do I get the datalogs?

 

 

 

 

The first flight with my unit, the GPS failed.  It never reacquired again, temps and software were no longer reporting for the GPS or LIO items.  I put about 800 nmi on the unit with it never acquiring before I had a chance to RMA the unit.  Hardware needed to be replaced.  Back from rework, the unit was recently reinstalled and the GPS failed on the first flight just prior to the FAF.  The GPS never reacquired the entire flight home (~25 min).  Back on the ground while on the phone with tech support, it was able to acquire, but lost it again after a few minutes.

Can you follow my statement now?

I believe these continued issues are a result of Avidyne not recognizing it has a larger reliability issue than patching a few software bugs.

I've been quiet about the issues I've been having until now, but the second failure straight out of the box is simply unacceptable.

I just received my unit back from RMA on Tuesday (3/31/2015).  My two GPS failures are unique from each other, not sure if they are similar to what other people ran into.

I have a 28V system.

The logs have already been sent to tech support, but it's after hours there (and now the weekend) and I'm supposed to fly to the coast in the morning - I hope the VFR forecast is accurate.  Next weekend up in the Bay area has me more concerned.

On today's flight, the GPS was working for the first 45 minutes before it died.  When it was working, I had a chance to tune in and ID a VOR, turn the CDI and watch the green line move on the 540.

When the GPS failed, although I could still hear the audio and the frequency had the blue ID box, I was not receiving VOR information on the CDI.  This is another problem for me because I was thinking that if the GPS died in flight, that at least I could still revert to an ILS, which now I cannot because the GS is tied to the 540.  I can't even use dual VOR functions so I'm down to a single VOR (of my kx-155a).

I hope this combo failure is not part of the design, and just some useful troubleshooting info.  I can't believe the FAA would allow the box to be certified with this type of failure.

Absolutely does, still waiting for the AOG callback that was supposed to call back "right away" last night.

Haven't been able to get my fuel flow working either although it is wired and configured correctly.

Sorry to see you are having all kinds of issues.

I agree we are at the point where we need to determine root cause because I believe this would be the 3rd unit in a row that was determined to have I/O issues although the symptoms have been different.  Please provide some specific guidance of how to provide useful data to you for your investigation.  I'm not sure trying a 4th unit is the best idea at this point.  Finding a root cause rather than having the symptoms go away will go a long way to regaining confidence that it'll remain solid in the clouds.

By the way, we cancelled our spring break trip to visit family due to this, there is a good chance I would have needed IFR capability.

That may be true, but since it takes down GPS reception, then from the user perspective this IS a GPS failure at best and possibly a larger system failure (when it took out my VOR indications on the CDI).

I've turned the unit off in flight several times to try to reset the GPS and power cycled the avionics switch when on the ground to reset the unit.  Some times I'd turn everything off while reading the manuals and go back and test 30 minutes later.  Once it lost GPS, it lost it for the rest of the day with one exception.  One time it didn't have reception the entire flight back, but reacquired on the ground while on the phone with tech support for a few minutes, but then lost it for the rest of the day.  Just as another datapoint, my experience is that it is much more likely to stay failed even when power cycling the unit after a failure and not for just that flight.  I was thinking there was a temperature component to the issue.

I offer this as a potential pointer to whats going on, knowing full well it could be meaningless. I have an IFD540 and Aspen setup in my airplane. It is a new install of everything, no reuse. It is running 10.0.2.0 and I have not, up until yesterday seen a GPS fault on the unit in probably 20-30 hours of flying in the US and Mexico. Yesterday, when taxiing from the fuel island at KLVK to my hanger, the unit suddenly showed a GPS fault and dead reckoning. I was in a hurry due to passenger needs, so didn't check the GPS satellite status or wait to see if it would recover on its own before shutting down. What is interesting is that I used to have a GX60 MX20 combination that was rock solid except that the MX20 blue screened on me several times in the exact same location with a general system fault. I do not know why this spot was problematic for the MX20. In two years of use I never had it do this anywhere else but in that one spot, taxiing on the ground back to my hanger. Error codes are not very clear for that unit but it looked like it thought it was getting garbage GPS data and so took itself offline.

My thinking is this could be due to some sort of radio interference bleeding over into the GPS receivers and corrupting the data. This location on the airport is off to the side of the ILS glide slope antenna, but is in front of it and there could be a strong side lobe there. I know the observation of loss of GPS sticks around for the IFD540, but once confused, the receiver software may get into a state where it's not recoverable. Perhaps the failures in GPS lock are due to radio interference with the GPS receiver at startup.

I pulled the logs from the unit today in case someone is interested in looking them over. I also pulled the plane out of the hanger today and checked it. Plenty of good satellites and immediate GPS lock. Go figure.

We will verify the fix is a solid fix and then determine how we roll it in.