Avionics power off mid-flight

[Pinecone]

When my panel is done, I will have a G3X on a back up battery.  A G5 with a 4+ hour internal battery.  An AERA 760 with battery.  And iPad with GPS. 

Belt AND suspenders.

 

[swsmith]

15 hours ago, PT20J said:

This is interesting. I just looked at the schematic for 25-0002 thru 25-0171 (the first batch of 231s which should all be 12V) and it shows an AUX bus breaker and a normally closed radio relay. I did not trace all the wires to be certain that the relay is powered through the AUX bus, but as that was standard practice, I'm reasonably certain that it is. The AUX bus is the circuit that feeds the breaker switches at the bottom of the pilot's instrument panel (landing lights, strobes, nav lights, boost pump, pitot heat, etc.). The purpose of the aux breaker is to protect the power wire between the main bus and the aux bus. Perhaps someone rewired this ship at some point?

 Next time I fly I’ll take a picture of the breaker panel. It did have extensive rewiring when all the garmin boxes were installed. 

[bradp]

On 9/30/2023 at 1:28 PM, swsmith said:

My 1979 K doesn’t have that. The relay is also the part that failed and it didn’t failed in a way that allowed power to still flow. I’ve heard the 24v systems do this but mine is a 12v system

I have also had my avionics radio relay fail in a way that powers down the circuit.  It’s not designed that way but it can still fail that way. I my case one of the spades for the relay contactons had been vibrated loose in the housing by time and the heavy gauge cable pushing down on it.  It bent the contactor so that it could not physically touch - so essentially it was in an always “energized” or radio power off state. 

 

[glbtrottr]

Yuuup.

So there I was a month ago flying big bear to compton in my k model. All avionics check out and say bye. Yikes

Lucky for me I always fly with a usb battery powering the garmin portable and have a handy dandy portable around - flying 1 mile south of class B Can be challenging at 160 knots….

No issues …


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