Garmin 430w lost satellite signals during last flight

[rbridges]

Everything was great, and then got signal loss message. Never saw that before. I ended up using stratus/foreflight and switching to VFR flight plan. Cycled the Garmin several times. It would reconnect and then lose signal after a minute or so.  Sometimes it would never get a lock.  Is it an antennae issue?  Waas installed prob 5 years ago. 

[Marauder]

Everything was great, and then got signal loss message. Never saw that before. I ended up using stratus/foreflight and switching to VFR flight plan. Cycled the Garmin several times. It would reconnect and then lose signal after a minute or so.  Sometimes it would never get a lock.  Is it an antennae issue?  Waas installed prob 5 years ago. 

Antenna would be high on my list as prime suspect.


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[rbridges]

Just now, Marauder said:

 

Antenna would be high on my list as prime suspect.


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Im supposed to go in for an MFD 1000 install in march.  I'll ask them when they have my plane. 

[7.Mooney.Driver.0]

When and where did you experience this issue? I think the navy has been doing some GPS jamming on the eastern side and the Caribbean.


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[rbridges]

19 minutes ago, siu1526 said:

When and where did you experience this issue? I think the navy has been doing some GPS jamming on the eastern side and the Caribbean.


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Worked great for 30 minutes then went haywire right around Valdosta and continued into Orlando.  Even continued when I cycled it back on while on the ground. I knew about the GPS notam, but Valdosta said no one else was having issues. 

[M016576]

57 minutes ago, rbridges said:

Worked great for 30 minutes then went haywire right around Valdosta and continued into Orlando.  Even continued when I cycled it back on while on the ground. I knew about the GPS notam, but Valdosta said no one else was having issues. 

Any handheld devices in the cockpit lose reception too?  If so- suspect your WAAS antenna.  The 430W antenna has a failure mode that can disrupt/jam the gps signal for about a 15’ sphere.  I found this out the hard way, which resulted in me shooting an ils approach using my obs/vor-> kns80 ils.  Keep those old vor skills handy, just in case all your gps’s get knocked out by a bad antenna!

 

[carusoam]

My installed Narco navcom was noisy enough to kill the GPS... depending on what VOR it was tuned into...

I ran into this challenge flying to SnF using VORs to navigate and a portable Garmin GPS for support...

The Narco came across as being jealous... 

Best regards,

-a-

[rbridges]

I did have my DME on, and I had my kx155 set to on the Orlando localizer, but that just receives, correct?  We had our cell phones on, but we've done all that before, and I know we've had the DME and radios running during instrument training with never a hiccup. 

[M016576]

This is the failure mode I was describing above.  It’s well documented on other forums, too (beechtalk, poa, etc)

Edited February 22, 2019 by M016576

[rbridges]

27 minutes ago, M016576 said:

This is the failure mode I was describing above.  It’s well documented on other forums, too (beechtalk, poa, etc)

Thanks. The stratus worked, so I'm not sure if  it's the situation where the antenna failed and jammed everything.  

[jma201]

I had the same issue.  A new antenna fixed it for me.

[carusoam]

Possibly an easy test to run... if the challenge is still happening...

The GPS has a satellite page that gives a hint to how many satellites are visible to the box and how strong their signal is...

Turn things on or off, one at a time to see if anything interferes with the satellite page data...

PP thoughts only, not a radio tech...

Best regards,

-a-

[Oldguy]

Had a similar situation when I was flying with another pilot, who was running the radios for me, in IMC. Shot the approach, and after we landed the 430W lost satellite connections. Turns out the other pilot switched over to ground and was transmitting on COM #2 and it killed the GPS. We were able to repeat  the problem and had it fixed when we got back to home base.

[rbridges]

1 hour ago, carusoam said:

Possibly an easy test to run... if the challenge is still happening...

The GPS has a satellite page that gives a hint to how many satellites are visible to the box and how strong their signal is...

Turn things on or off, one at a time to see if anything interferes with the satellite page data...

PP thoughts only, not a radio tech...

Best regards,

-a-

I was watching it on boot up.  Would see a handful pop up and disappear. Then a few pop up and disappear. I talked with my local avionics shop.  Gonna take it in and have it tested. 

[81X]

For what it’s worth, I experienced LOI on my GTN750 when an instructor brought along a SPOT messenger sending breadcrumbs. No SPOT, no problem. 

[Marauder]

For what it’s worth, I experienced LOI on my GTN750 when an instructor brought along a SPOT messenger sending breadcrumbs. No SPOT, no problem. 

81X brings up a good point. Make sure you didn’t introduce the problem by bringing something new into the cockpit (a Spot, new cigar charger, etc.). GPS signals can be interfered with.


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[BP03]

Had similar problem with my 430W - spent $$$$ in Avionics shops and Garmin sent a loaner unit before i figured it out.  Old ELT was within 3-4' of GPS antennae.  When i flew close to ground based transmission towers i would see intermittent loss of GPS problems.  Apparently interference between the transmission signals, ELT and GPS.  I unplugged the ELT and re-flew common problem areas without issue.  I replaced the old ELT with a 406 unit and moved further away from the GPS antenna and no more problem!

[Marauder]

Had similar problem with my 430W - spent $$$$ in Avionics shops and Garmin sent a loaner unit before i figured it out.  Old ELT was within 3-4' of GPS antennae.  When i flew close to ground based transmission towers i would see intermittent loss of GPS problems.  Apparently interference between the transmission signals, ELT and GPS.  I unplugged the ELT and re-flew common problem areas without issue.  I replaced the old ELT with a 406 unit and moved further away from the GPS antenna and no more problem!

Why was the ELT causing the issue? It’s not transmitting anything unless it is activated.


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[BP03]

Good question, but I have no idea how the ELT/Antenna caused the GPS interference.  I can confirm the problem went away when i disconnected the ELT and returned when it was reconnected while flying close to towers.  If you're having the issue rbridges described try disconnecting the ELT from the antenna and power it off.  It worked for me...maybe someone else can explain why??  GPS puck was mounted above the luggage area and the ELT was mounted on the hat rack if that helps.  The Garmin install manual says no antennae's or electronic devices within 3-4' of the GPS puck, they must have a reason...

[kortopates]

Good question, but I have no idea how the ELT/Antenna caused the GPS interference.  I can confirm the problem went away when i disconnected the ELT and returned when it was reconnected while flying close to towers.  If you're having the issue rbridges described try disconnecting the ELT from the antenna and power it off.  It worked for me...maybe someone else can explain why??  GPS puck was mounted above the luggage area and the ELT was mounted on the hat rack if that helps.  The Garmin install manual says no antennae's or electronic devices within 3-4' of the GPS puck, they must have a reason...

I can't explain it either, but it's been a common issue enough that any installer should be well aware of it these days. I am sure Jerry can explain it.


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[jsimmons619]

For what its worth, I was occasionally losing GPS satellite information; primarily at startup..  I replaced GPS antenna to no avail.  At suggestion of avionics shop I replaced the Garmin 430W internal battery (with no error information from the Garmin unit itself) and it definitely stopped happening.  My 430W was about 10 years old at the time.

[rbridges]

11 hours ago, BP03 said:

Good question, but I have no idea how the ELT/Antenna caused the GPS interference.  I can confirm the problem went away when i disconnected the ELT and returned when it was reconnected while flying close to towers.  If you're having the issue rbridges described try disconnecting the ELT from the antenna and power it off.  It worked for me...maybe someone else can explain why??  GPS puck was mounted above the luggage area and the ELT was mounted on the hat rack if that helps.  The Garmin install manual says no antennae's or electronic devices within 3-4' of the GPS puck, they must have a reason...

I saw that on several forums, too.  Unfortunately, mine seems to be consistent and not location specific, or radio frequency dependent.  I'm going to the avionics shop next week.  My money is on the antenna, but we'll see...

[TaylorA]

This same thing happened to me tonight in night IMC in the mountains as well. I wanted to see what the end result of your 430 gps failure, my number is 434-251-5850.  I want to do some troubleshooting and get your perspective before it goes to the radio shop later this week. 
 

thanks for your help!

Taylor

[carusoam]

Welcome aboard Taylor!

I’ll let @rbridges know you are asking...

Just know there are many different reasons for this situation to occur...

So... if you don’t mind describing all you know about your installation, and where you were flying when this occurred...

Common challenges are often, antennas, their location, their proximity to other antennas, the coax cable type they are using...

Then there are the times when the GPS system has been locally shut down for various reasons...

PP thoughts only, not an avionics guru...

Best regards,

-a-

[rbridges]

7 hours ago, TaylorA said:

This same thing happened to me tonight in night IMC in the mountains as well. I wanted to see what the end result of your 430 gps failure, my number is 434-251-5850.  I want to do some troubleshooting and get your perspective before it goes to the radio shop later this week. 
 

thanks for your help!

Taylor

It ended up being the antenna.  The avionics guy said it before I finished my sentence.  Has worked fine since.