What was found
DURING REPLACEMENT OF NR 1 AND NR 2 AVIONICS MASTER SWITCHES IT WAS NOTED THAT THE AVIONICS BUSS TIE SWITCH WAS MISSED WIRED. THE BUSS TIE SWITCH IS TO BE WIRED FROM THE OUTPUT OF AV NR 1 BUSS MASTER TO OUTPUT OF THE AV NR 2 BUSS MASTER. THIS AIRCRAFT TIE SWITCH WAS WIRED FROM THE INPUT OF THE AVNR 1 BUSS MASTER TO THE OUTPUT OF THE AVNR 2 MASTER. THIS ALLOWED THE BUSS TIE SWITCH TO POWER THE NR 2 AVIONICS BUSS WITHOUT EITHER BUSS MASTER SWITCH ON AND WOULD NOT ALLOW THE NR 1 BUSS TO BE CROSS TIED TO THE NR 2 BUSS IF THE NR 1 SWITCH HAD FAILED. THIS IS THE SECOND AIRCRAFT FOUND LIKE THIS AND BOTH AIRCRAFT APPEAR TO HAVE THE FACTORY INSTALLED SWITCHES AND WIRING IN THEM.