What was found
PROVIDING HAZARDOUSLY MISLEADING INFORMATION TO THE FLIGHT CREW IS A MAJOR FAILURE CONDITION FOR THE AIRCRAFT. SINGLE LATENT FAILURES OF CDI DEVIATION OUTPUT WIRES (SHORTED AND/OR OPEN) RESULT IN A NON-FLAGGED AND CENTERED DEVIATION BAR, INDICATINGAN ON-COURSE LOCALIZER OR GLIDE SLOPE WITHOUT THE CAPABILITY OF DETECTING AND FLAGGING THE MALFUNCTION. A COUPLED FLIGHT DIRECTOR/AUTOPILOT WOULD CONTINUE OPERATING UNGUIDED, WITHOUT ALERTING THE COCKPIT CREW! THIS CAN BE HAZARDOUSLY MISLEADING. SN 1187 & 1189