ADS-B weather fails

[Eric_Greenwell]

April 9, I flew from RLD to AWO (Arlington, WA), then two shorter out and return flights from Arlington. The ADS-B radar images and traffic depiction appeared to work perfectly.

April 10, I flew from AWO to RLD, and the ADS-B did not display any radar images, and the status showed this:

ADS-B Status: Not found
NEXRAD RGNL: Age - -:- -
NEXRAD CONUS: Age - -:- -

TIS did work until I crossed the Cascades to where there is no TIS.

Dynon support had me check the ADS-B page in SkyView the next day: the TX and RX bits were incrementing, the sentences incremented and were good, and the red light on the ADS-B box was flashing. All good.

Today, I flew, and the ADS-B functioned completely normally, bringing radar images, traffic, etc.

What happened on April 10?

 

[dynonsupport]

Eric,
Were you getting a caution message that ADS-B was offline?

It sounds like during that one flight the ADS-B module wasn't running. All I can think is that either it was unpowered due to some failure of wiring, or that the module itself failed to boot even though it had power.

I think all you can do is see if this happens again, and if it does, power cycle the ADS-B box if you can via a breaker or other switch and see if that recovers it right away. If it does, then your ADS-B module might have an issue. If it doesn't, then you wiring likely does.

 

[Eric_Greenwell]

Were you getting a caution message that ADS-B was offline?

Yes, I did, though I don't remember when I became aware it, and I didn't think to power cycle it at anytime. I'm pretty sure I didn't get the "TIS NOT AVAIL" message until I was crossing the Cascades. Are online/offline or warnings like that stored in the log file?

I wiggled all the wiring and connectors near the ADS-B box, but it didn't seem to affect anything. During the wiggling, I discovered one of the connector "hold down" screws was about 2 turns loose and the other was maybe a half turn loose, so I finger tightened both of them.

It was an eery feeling, flying without the traffic info along the Arlington/Issaquah route, wondering when an airliner was going to pounce on me (transponder was still working, fortunately).

 

[dynonsupport]

The system automatically backs off from ADS-B to TIS on a failure.

TIS comes from the transponder. This went off when you flew towards the Cascades because you flew out of Sea-Tac's radar coverage.

The alerts are are in the data log, but given all you said, it's pretty clear we were getting no data from the ADS-B box. Just keep an eye on it and see if it repeats.