Document ID: chunk:federal_register_of_legislation:F2016L00368:body:0:p2
Version: federal_register_of_legislation:F2016L00368
Segment Type: other
Provision Reference: 
Character Range: 2816–4591

CASR 1998.
                Note:  Generic guidance on the testing of transponders is available in AWB 34-013 and AWB 34-09.
                For Requirement 3: Before further flight after the Requirement 1 or 2 tests.
                This AD commences on 23 March 2016.
Background:     AD/RAD/47 was originally issued to introduce a procedure additional to the transponder self-check prescribed in paragraph (4) (k) of section 5 of Schedule 5 of the Civil Aviation Regulations 1988 (CAR 1988), and to align with the requirements of overseas civil aviation authorities.
                Amendment 1 advised of a new code, compatible with air traffic control requirements, that was to be used when testing transponder systems.
                Following the deployment of new Mode S radar interrogators in Australia, it was discovered that variation in the height of reply pulses transmitted by the transponder could be misinterpreted by the interrogator and this may cause the Mode A code to appear to spontaneously change during flight. This may generate short term conflict alerts to be displayed to air traffic controllers.
                Amendment 2 introduced serviceability checks to confirm that transponders utilising ETT are performing to the specifications to which they were originally certified.
                Amendment 3 was issued to limit the applicability of the AD to Part 42 aircraft only.
                Amendment 4 is issued to update a regulatory reference in the compliance section from regulation 42M of CAR 1988 to regulation 42.140 of CASR 1998. This AD will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards.

William M. David
Delegate of the Civil Aviation Safety Authority
18 March 2016