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IFD 440 GPS failure

FORANE

Well Known Member
IFD440 Issues with GPS Lock

So I bought an avidyne IFD440, new on vaf classifieds, and installed it in my lancair. Slid out the 430W, slid in the IFD 440 and configured it. 1st flight after installation it lost GPS lock intermittently through the flight for a total of about 1/2 of the 2 hour flight.

Same GA-35 GPS antenna that worked fine for the 430W. Avidyne tech support said the antenna is required to be mounted outside, not on the shelf in the empennage under the composite fuselage like mine has been for years. They didn't answer why it worked for the 430W but not the IFD440.

I also noticed the IFD440 runs terribly hot to the touch. I can't touch it for longer than about 5 seconds without burning my fingers. No answer from tech support on this either.

Love the features but I am beginning to question the purchase.

Questions:
Have you seen issues with IFD 440/540 GPS lock failure?
Have you had success with mounting a GA-35 for use with an IFD under the cowling? or on the turtle deck? or only mounted outside as Avidyne says is mandatory?
Are you using a GA-35 antenna or another antenna?
Is it normal for an IFD to run hot?
Do GPS antennas such as GA-35's either work or not, or does their function degrade with age?

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I would have pics of the 430w locked onto many satellites but I left it at home after installing the IFD. Now, I am out of state and possibly grounded depending on if conditions are IFR when it comes time to go home.
 
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Questions

Have you seen issues with IFD 440/540 GPS lock failure?
I have not while flying. It struggles a bit when the plane is inside my metal hangar though. As a point of comparison, My Garmin GDU-375 with a GA-57X antenna mounted in the wingtip will get a lock just fine in the hangar.

Have you had success with mounting a GA-35 for use with an IFD under the cowling? or on the turtle deck? or only mounted outside as Avidyne says is mandatory?
Antenna mounted outside on the top of the aft fuselage.

Are you using a GA-35 antenna or another antenna?
I am using a Garmin GA-37 (GPS and XM combo).

Is it normal for an IFD to run hot?
YES! The sides of the bezels will get uncomfortably hot to the touch - although it doesn't rise to the level of "burning" IMHO. The IFD 440 manual says as much - so I was not surprised. My avionics stack has always been somewhat toasty even before I installed the 440. I am planning to add an avionics fan to feed the port on the back of the 440 tray just to hedge my bets.

Here is an excerpt from the 440/540 installation manual:
In the event the system feels excessively hot or if an Overtemp Caution Advisory System
message is presented on the display, there are some diagnostic tools provided in the
IFD5XX/4XX to assist in finding more optimal cooling installations. In Maintenance Mode,
select the ?Status? tab along to bottom edge of the display and then press the ?Info? Line
Select Key as needed until ?Temps? is displayed. Note the hottest source(s) on that page and
supply that information to Avidyne Technical Support to include both the source and the
associated temperature for follow-on guidance.

The metal bezel of the IFD5XX/4XX is intentionally designed to radiate heat away from the
internal components and out of the unit. This can have the effect of a bezel that may be
warm to the touch. This is considered normal. Note that the rubber bezel buttons will not
conduct this heat and should not be warm. This condition will be more noticeable on hot
days or during long ground runs.

Do GPS antennas such as GA-35's either work or not, or does their function degrade with age?
I have no idea

As a general comment, I am very pleased with my IFD440 purchase - it has been a joy to use with no issues. Mine was a fresh install - so I am using the tray, etc that came from Avidyne.
 
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IMHO no avionics should be so hot that they can burn you.
As to gps antenna placement: To gain the TSO the manufacturer had to show that it worked under certain worst-case conditions. You can fly for years without ever encountering such conditions, so having done so means nothing. Also, technically, not following the manufacturer?s approved installation instructions voids the TSO.
 
Is my thread title improper or inaccurate?

I just received this PM:

I?m not trying to be too critical but it would be more helpful for everyone, intending purchasers & manufacturers, if the subject was more to the point & not appearing to indicate that your unit had failed. Many posters unwittingly do this & it?s not really helpful - sure gets people?s attention though.
Imagine the reaction if someone posted their RV or Lancair failed - not helpful.
 
Thread Title

Maybe something like "IFD440 Issues with GPS Lock"?

BTW - I was not the one who sent the PM - just to be clear.
 
430W swapped out for IFD440

I made the switch from a 430W to an IFD440 about 18 months ago using the old tray and antenna. It has worked perfectly from the start although I will agree that it seems hotter to the touch compared with the 430. I love its many features and ease of use.
 
I run an IFD540 with a GA-35 antenna mounted outside just aft of the back window, no issues on GPS reception outside the hanger. From the photo it appears you do not have enough SVs to get get a fix solution lock. The relative signal strength looks OK, so I would guess you do not have a cable/connection loss problem. The IFD manual suggests a a GPS Fault indication may require a manual power cycle to restore operation (GPS lock).

I have not noticed any unusual heat issues.

Make sure you are running the 10.2.0 firmware version or the just released 10.2.1.

John Salak
RV-12 N896HS
 
First flight with mine I had a GPS fail message. I have a small Garmin GPS puck antenna located right next to the original Garmin antenna which never gave any trouble but is in violation of install requirements of both mfg’s. So I moved it and apparently fixed the problem. My antenna is under a glass deck on my Cozy MKIV

I’d like to point out Garmin has a minimum antenna attenuation requirement that is typically accomplished by adding extra coax length in cases where the run is short, sometimes inline attenuators are used. Avidyne also has this requirement but it is much less attenuation than Garmin calls for and tech support told me I could ignore the spec if I have further problems and just cut it to required length. And they did feel like it was the anttenuation that caused my fail, not the close proximity of the other antenna, but it has worked flawlessly since I move the other antenna. I will remove the additional length anyway when I get a chance.
Tim Andres

Edit, mine doesn’t seem any warmer than the 430
 
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Just bought a new ga-35 antenna. Didn't want to have to crawl in the empennage to try moving the current antenna. Will try different locations. Will report back if successful.
 
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