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AFS 4500 “No GPS”

dougweil

Well Known Member
Hey gang,

My RV-7 has an AFS 4500/3500 setup being driven by a 430W (via ARINC). Yesterday for the 4th time in the past 9 years of flying I was cruising along and got a “NO GPS” warning flag on both screens. This freezes the map position display and I have to resort to the small map display on the 430W (no flight director or CDI). The only solution seems to be powering off the AFS boxes (requiring turning off the master switch since they are directly wired to ships power) and do a reboot and all is well. Years ago Rob Hickman told me this is caused by a possible very short interruption in the RS-232 signal from the 430W. Anyone else ever seen this? I can’t seem to duplicate it and since it only happens once every couple years it’s hard to track down!!
 
Did you check the notams to see if there was any military gps jamming going on where you were flying?
 
I had that problem. I thought it was probably my ARINC module but turned out to be a bad pin insertion on the 430W side after installing ADS-B.

Rob, or Shawn, or Jonathon at Advanced Flight are pretty responsive when you call them on the phone. I'd start there (and I have). The AFS Forums are also a good place to get input from those guys.
 
Thanks for the insight. GPS signals were all strong on the 430 and Freeflight ADSB. I’ll do a little connector inspection and then talk to AFS.
 
No gps

You may want to try a serial port loop back test, for the port assigned to the gps, in your 4500.

Gary
 
Same issue…

I had the same failure on my dual AFS, while imc .. Would appreciate if op can share how they resolved it.

I am kind of thankful that things turned out ok and now reluctant to fly ifr with AFS systems.
 
I had the same failure on my dual AFS, while imc .. Would appreciate if op can share how they resolved it.

I am kind of thankful that things turned out ok and now reluctant to fly ifr with AFS systems.

Unfortunately it’s hard to assist with out some facts on what happened and what you’ve done so far to troubleshoot.

It could be a hardware issue, or it an issue with an open connection in the wiring.
 
Symptoms same as op

Symptoms are same as OP.

Everything working fine for a long period, then out of the blue no gps sign on the EFIS. Gramin 430 still worked fine, but no signal to AFS.

Yesterday ‘s flight was long cross country from CA to Seattle. All looked great until the last hr. Restart after shutdown fixed it - of course not an option while in air.

Panel was professionally built by Aerotronics, I don’t think wiring is an issue given the symptoms.

AFS support in the past have been not stellar. Last time I had questions I ended up teaching the support a thing or two about the system he was representing.

I’ll do some additional tests based on pg 74 on their manual, but given my tests so far it seems AFS software or hardware issue. Hence my question to op if he got to the bottom of his problem.

Ashish
 
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