The ATSB provided the Civil Aviation Safety Authority (CASA) with written information about this safety issue and then followed up with a meeting on 11 February 2015 to discuss the issue. In correspondence following that meeting, CASA advised of the following safety action:
CASA has reviewed its processes and procedures applicable at the time for the appointment of CAR 35 authorised persons and concluded that although CAR 35 regulation referred to design standards and not airworthiness requirements, one of the usual limitations on all CAR 35 instruments was to consider relevant/applicable ADs and therefore the issue of AD consideration was covered in this way. Nevertheless, it appears, on the basis of the ATSB investigation, that, at least in one case, a CAR 35 design approval was given without considering applicable ADs.
In order to assess the potential scope and establish direction of any future actions, if any, CASA has made a decision to conduct a review of the approach of all former CAR 35 authorised persons, before 2003, with regards to the assessment of ADs in their approvals made under CAR 35 regulation. The data for this review will be collected during the scheduled surveillance events, for currently active design authorised persons, and via communication in writing with inactive and retired (former) CAR 35 authorised persons that were active before 2003. Once the results are received, an assessment will be conducted and further action decided. If in the course of collecting data, any adverse trends are noticed, an appropriate interim action will be initiated.
Subsequently, following their review of the draft report, CASA advised that they would not be carrying out any further safety action in respect of this safety issue.
The ATSB acknowledges CASA’s initial action to address this safety issue. However, the ATSB is concerned that this action does not specifically examine the over 1,000 Australian Parts Manufacturer Approvals undertaken by the Regulatory Reform Program Implementation (RRPI) team in 2003. The effect of the policy direction given to the RRPI team, and lack of CASA files containing records of CASA’s engineering assessments of those parts, means there is no assurance that the tie rod manufacturer’s other RPPI-approved APMA parts were not similarly affected by the issues identified with the tie rod replacement parts approval. In support of this, the ATSB has become aware that at least one other part listed on the tie rod manufacturer’s APMA approved by the RRPI, for the DHC-1 Chipmunk aircraft, is the subject of an airworthiness directive that places a life limitation on the part. Like the APMA for the tie rods, there is no mention of the airworthiness directive, or life limitation, on the associated APMA documents.
As a result, the ATSB has issued the following safety recommendation.