What was found
(CAN) UNCOMMANDED SHUTDOWN DURING FLIGHT TEST FOR CERTIFICATE OF APPROVAL PURPOSES, THE ENGINE WAS SHUTDOWN AND RELIT IAW OPERATING HANDBOOK. 2 MIN AFTER RE-LIGHT, THE ENGINE SHUTDOWN UNCOMMANDED AND COULD NOT BE RE-STARTED. AN UNEVENTFUL SINGLE ENGINE LANDING WAS ACCOMPLISHED AT THE POINT OF DEPARTURE. POST FLIGHT INSPECTION FOUND A SEIZED GAS GENERATOR MODULE AND BRONZE PARTICLES IN THE OIL FILTER.