im not sure if its operator error, as jabiru claim on every occasion, as there are 3 main failure modes.
Rotax engines are maintained by the same type of people, but have varied failure modes, and a majority are not related to the engine itself, but the accessories such as ignition modules, carbys etc.
to me, an obvious serious failure mode such as the through bolt failures to me suggest a design flaw. but sadly, IMO, jabiru seam to have their heads in the sand when searching for a solution. with no feedback to operators on the cause of a failure.
I have spoken to engineers that maintain jabirus, and have had no issues right to TBO, and they have described the reasons behind the failures, and yet, nothing is done to address the issue, No SB, no changes to maintenance manuals, nothing.
I think CASA is being a bit harsh with these restrictions, but when has CASA ever done anything to help improve aviation..... it would rather see loss of livelihoods, the demise of a local aircraft manufacturer and a large number of schools than try to resolve the issue and to improve the industry...