Document ID: chunk:federal_register_of_legislation:F2006B06534:body:0:p2
Version: federal_register_of_legislation:F2006B06534
Segment Type: other
Provision Reference: 
Character Range: 3487–5666

removed from the AFM.

            Note 2: It is the responsibility of the operator to check with the design approval holder of the ACAS II installation that TA/RA VSI-TCAS equipment software modification doesn't alter the initial aircraft ACAS II installation airworthiness condition.

            Note 3: DGAC AD F-2004-053 and Thales Avionics Service Information Letter THAV/SIL-1064 Issue 03 dated 4 June 2003 refer.

 Compliance: For Requirement 1 - Within 15 days after the effective date of this Amendment.

            For Requirement 2 - Remains unchanged as 'Before 31 December 2007'. This Amendment becomes effective on 21 April 2004.
            Background: The TA/RA VSI-TCAS indicator displays an "RA fail" message when a "maintain - Don't Climb/Don't descent" resolution advisory (multi-aircraft encounter configuration) is issued by the ACAS II computer. Normally in this condition, the TA/RA VSI-TCAS indicator should display on the vertical speed scale a green arc of
            ±250 ft/min with the rest of the scale red.

            The probability of encountering the operational scenario leading to this resolution advisory is low but this situation, where the aircraft is located between two others, one below and one above, is critical. This incorrect display may lead to a hazardous situation if the wrong interpretation of the required manoeuvre is made by the crew. It should be noted that traffic advisory indication on the TA/RA VSI-TCAS display and aural annunciation ("Maintain Vertical Speed, Maintain") are correct.

            The original issue of this Directive initially required the inclusion of a temporary amendment in the AFM followed by modification to the software to correct the display on the TA/RA VSI-TCAS indicator.

            This amendment continues the requirements of the original issue adding part number 457400SB0711 to the Applicability Statement.

            The original issue of this Directive became effective on 14 April 004.

 James Coyne
 Delegate of the Civil Aviation Safety Authority 15 April 2004

 The above AD is notified in the Commonwealth of Australia Gazette on 21 April 2004.