What was found
TAKEOFF REJECTED AT 50 KTS DUE TO FAILURE OF DU 1, 2 AND 3, AS WELL AS FMS 1 AND RMU 1. ALL AVIONICS REPOWERED WITHIN 15 SECONDS. THE FOLLOWING AMBER CAS MSG. REMAINED: FADEC REV ADC R, YD OFF LOWER, FADEC FAULT R A, FADEC FAULT L A. TROUBLESHOT TO DEFECTIVE IC-800 IAC COMUPTER ON LT SIDE. R & R NR 1 IAC WITH SPC UNIT IAW MM CH 34-25-01, REQ 42. LOADED NAV, CUSTOM AND ACFT DATABASES. OPS CHECK GOOD.