Thanks for the reply. looking at the CASA website this is all I can find... the reference to the "Relief for Jabiru engine limitations. Jabiru engine limitation relief | Civil Aviation Safety Authority I can't find anything else by way of back story, stats qualification or process. I saw the Mr Skidmore YouTube Senate Committee discussions and I was totally underwhelmed. It is like a piece of string sticking out from under a curtain. On the other end there might be anything from a mouse to an elephant. If this process is how CASA comes to a decisions that affects the livelihood of industry sectors, I would be hoping to see more rigor and professionalism. From my limited view, looking at the incident reports at the time I couldn't see the need for a blanket ban on the engines, just the appropriate A/D's and some public awareness campaign for people tampering with their own engines. If this is how CASA works more broadly, by decree/whim/fiat/prejudice etc, time for a real review. Starting at the people and process behind the Jab engine ban. If there is nothing in it, their position and cred is strengthened.