While looking for the date of the last pitot-static certification, I found the following snag and rectification in an aircraft journey logbook.
Avionics master comes on with battery switch. Found stall warning power connected to avionics bus and stall warning system connected to pilot instrument light power.
I picture some inadequately supervised apprentice somewhere in Temiscaming or Chatanooga playing with the panel wiring like an old fashioned telephone switchboard. That would be why our PRM has decided not to have remote shops supervise the maintenance work.
The engineer comes by to tell me which breaker he will put the new tachs on. It's
so completely unrelated that I've forgotten what it was, maybe with the landing light on the CB for the "rear cabin door open" warning light (I just looked it up).
"There are a couple of unused circuit breakers behind my elbow in the cockpit," I mention, assuming that it is neater to have every piece of equipment on its own. He already knows about the spares, but explains that it would take another hour of aircraft disassembly to wire the tachs in there. He has done an electrical balance and there is plenty of room for them to share. A light bulb goes on for me, as I now realize why two airplanes of the same type don't have the same equipment on the same circuit breakers. Anything that isn't original factory equipment is just wired into whichever breaker was convenient to the person who installed it.