Recommendation

The maintenance and testing requirements for flight data
recorders (FDR) and cockpit voice recorders (CVR) are not
explicitly defined in Australian regulations. ICAO Annex 6
requirements are accepted as the minimum requirement to be met by
operators when submitting Schedules of Maintenance for CASA
approval. ICAO Annex 6, Part 1, Attachment D, Flight Recorders,
provides guidance for pre-flight checking, inspection and
calibration of flight data recording and cockpit voice recording
systems.

CASA guidance in relation to flight data recorder maintenance is
set out in CAAP 42L-4(0), and includes reference to ICAO Annex 6
and EUROCAE ED-112.

In light of this recommendation, CASA will review the
maintenance requirements for flight data recorders and cockpit
voice recorders against the relevant international standards, and
will consider in particular whether minimum requirements for such
maintenance should be prescribed.

In the interim, CASA will review the existing guidance material
with a view to providing more specific maintenance interval
guidelines.

CASA will be providing additional training in the maintenance of
FDR/CVR systems for airworthiness personnel. This will enhance
their knowledge in these systems and will assist them when
evaluating aircraft systems of maintenance.

However, as an initial comment, CASA considers that there is no
substantive need for a maintenance check of the CVR to be conducted
by actually listening to the tape. It is likely that a functional
system check can confirm the fidelity of the equipment rather than
actually needing to listen to the tapes, as this has the potential
to destroy the efficacy of the CVR recording process.

At the time these amendments to the Civil Aviation Act and Civil
Aviation Regulations (1988) were developed (ATSB insertion: to
allow for listening to CVR audio for maintenance purposes - see
R20060006) the existing standards for the maintenance of CVR's were
also reviewed. Based on this review in combination with the Act and
Regulation amendments CASA believes there are appropriate standards
in place for the maintenance of CVR's.

This response restated the CASA response of 22 May 2006.

The ATSB notes that CASA have reviewed the existing standards
for CVR maintenance, in light of the amendments to the Civil
Aviation Act and Regulations (facilitating access to CVR recordings
for maintenance purposes).

While the ATSB acknowledges that this (and previous) action
meets the explicit requirements of the recommendation, the outcome
of the review, however, (that there are appropriate standards in
place for the maintenance of CVRs) does not serve to address the
intent of the recommendation, which was to effect an improvement in
the reliability of these systems.

The ATSB will continue to monitor and pursue the issue of flight
recorder maintenance standards, given the importance of the role
that this equipment plays in the safety investigation process, and
the risk to the effectiveness of future investigations presented by
unserviceable CVR and flight recording systems.