Over 3500 PT6A engines are using the only FAA approved Supplemental Type Certificate for “Instructions For Continued Airworthiness” to increase TBO to 8000 hours.
Supplemental Type Certificate Program
The More Supplemental Type Certificate for an 8000 Hour TBO is equivalent to the Pratt Whitney Canada Type Certificate for a 3600 Hour TBO. Source (FAA SAIB: NE-08-40).