I see that the NZ CAA investigated this fatal accident rather than TAIC. Surely not very independent? Though there is a statement:
A CAA field safety adviser had visited the maintenance organisation during the time that the maintenance was being carried out on ZK-HVN. The CAA officer discussed the issue of the absence of a full time certifying LAME with the CEO and gave him advice on the requirements in respect of direct supervision of the unlicensed personnel by the certifying LAME.
Advice seems to be at the limit of their authority as the report also explains that:
Prior to 1992, legislation required that all maintenance organisations be approved by the Director of Civil Aviation, and because of this the CAA had an active inspectorial role for. Maintenance organisations were regularly visited by the CAA inspectors to check performance against standards set out in both the company procedures manual and the existing regulations.
The legislative amendments of 1992 brought about by the ‘Swedavia McGregor report’ changed the way aircraft maintenance was regulated.
The smaller general aviation maintenance companies performing maintenance on aircraft under 5700kg, or of 9 seats or less were, and still are, no longer required to be approved. The CAA does not currently conduct scheduled inspections to measure the performance of these organisations, but has in the past conducted unscheduled ‘spot checks’.
Followed by a number of internal CAA recommendations.