AD NUMBER: 2004-16-14
MANUFACTURER: TA/RA VSI-TCAS indicators
SUBJECT: Airworthiness Directive 2004-16-14
SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Thales AvionicsTA/RA VSI-TCAS indicators, installed on but not limited to certain transport category airplanes equipped with TCAS II change 7 computers (ACAS II), that requires a revision to the airplane flight manual (AFM) to advise the flight crew to follow the audio annunciation when an RA fail message is triggered during a multi-aircraft encounter. This action also requires modification of the software for the TA/RA VSI-TCAS indicator, which would terminate the requirement for the AFM revision. This action is necessary to prevent the TA/RA VSI-TCAS indicator from displaying conflicting "RA FAIL" message during a multi-aircraft encounter, which could result in the flight crew ignoring the correct aural command and traffic display information if the flight crew believes the TCAS II computer has malfunctioned, and consequently lead to a mid-air collision with other aircraft. This action is intended to address the identified unsafe condition.

FMI: www.avantext.com/DailyADIndex.ASP?AD=20041614