Andy, I'm not sure if you knew, but the AMA used to Certify turbines, and turbine manufacturers had to go through a process to become certified. Then it was dropped to any engine that is currently in production. I'm not current on all the rules associated with this, but I think even homebuilts now are allowed without certification, but don't quote me on this.

Regardless, if the turbine is a manufactured product from a company that is at least partially in the business of building model turbines, you are AMA compliant.