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Re: Intermittent loss of GPS Signal: Possible causes? (same issue one year on; after repair)

PostPosted:Mon Jan 20, 2020 2:48 pm
by rikur_
Any 4G devices in the aircraft?

Re: Intermittent loss of GPS Signal: Possible causes? (same issue one year on; after repair)

PostPosted:Mon Jan 20, 2020 4:42 pm
by T67M
I've had many occurrences when one faulty GPS antenna can appear to work correctly but can cause other nearby (within 20m) GPS antennas to fail. This is why modern installation standards call for resilient GPS antennas to be sited as far apart as possible - I usually aim for 60+m, but I have the luxury of working on large buildings! On an aircraft, you'll be lucky to get 5m between the aerials, hence I'm wondering if you have a faulty GPS antenna. I believe you've already had one replaced - but maybe the other one needs to be replaced too.

Re: Intermittent loss of GPS Signal: Possible causes? (same issue one year on; after repair)

PostPosted:Mon Jan 20, 2020 5:47 pm
by rjc101
I've seen similar caused by a Cigarette lighter charger in use, which wasn't there when the aircraft went to the maintenance people. Some of them are *really* horrible in what they chuck out, even if they don't impact the audio on the radio.

Re: Intermittent loss of GPS Signal: Possible causes? (same issue one year on; after repair)

PostPosted:Mon Jan 20, 2020 5:52 pm
by Paul_Sengupta
I thought I'd asked about chargers...though that may have been on a similar thread for someone else's similar problem.

Yes, check chargers or anything which may cause interference. There was an issue some years back whereby tuning in certain frequencies on a certain radio would cause the GPS to go out.

Re: Intermittent loss of GPS Signal: Possible causes? (same issue one year on; after repair)

PostPosted:Tue Jan 21, 2020 8:36 am
by Charliesixtysix
Have you tried running any gps enabled devices ( eg phone or tablet running your preferred navigation app) inside the cockpit but independent of a/c systems to see if it suffers the same outages?