This investigation is ongoing and will analyse a number of additional aspects including, but not limited to:
a comparison between VH-registered light sport aircraft with the same engine models;
a comparison of factory built and amateur-build aircraft;
an analysis of the different engine models from Jabiru and Rotax;
an analysis of the engine failures with respect to both the total engine hours and the hours since last service;
an examination of the causes of the failures, to identify any potential systemic failure mechanisms;
an examination of the effect recent engine changes made by Jabiru have affected engine failures and malfunctions.
On the surface, it appears the current target is RAA engines and RAA engines that are creeping into the VH / GA domain. If conventional GA engines are in a happy place in CASA's eyes then what is their acceptable level of risk. Can there be 2 levels of acceptable risk, 1 for GA and for RAA? This just serves to discriminate by focusing on RAA in my opinion. I'm not suggesting this situation need not be looked at, however, there needs to be a benchmark set so goals can be achieved in the short term.
Out of interest, if you take GA Jabiru and Rotax engines out of the annual ATSB statistics, do stats for conventional GA engines improve or deteriorate?