In the enthusiasm to condemn what may be erratic action by CASA, I'm surprised at how readily the seriousness of the underlying problem has been put aside. First, the high failure rate of Jab engines relative to alternatives has been an open secret for years. And there are many reports on this site and elsewhere of the manufacturer being slow or unwilling to respond to the problem(s). Second, RA Aus has clearly failed to be effective in addressing the issues with the manufacturer, if it ever tried. To compound that, its failure to publish openly detailed comparative statistics added to the obscuration of the engine(s) issues.
The letter from which Kharon quotes is naive and embarrassing. It's heavy on RA Aus commercial self interest and light on addressing legitimate safety concerns about power plants used in aircraft often flown by student pilots and relatively inexperienced recreational pilots. So it's OK to take off with a sub-standard engine because RA Aus students practise forced landings? Give me a break.
You can argue that the CASA process was not ideal, and I might also argue that if I knew all the facts, not just those coming from selected quarters. But with Jabiru unresponsive, and RA Aus ineffective, how long did you expect CASA to sit on its hands?