As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) LH ENGINE COWLING SEPARATED FROM AIRCRAFT IN FLIGHT. THE TOP COWL WAS JAMMED ON THE LEADING EDGE OF THE OUTBOARD WING BY THESLIPSTREAM WHILE THE BOTTOM COWL WAS LOST. THIS WAS THE FIRST FLIGHT AFTER THE COWLS WERE REMOVED TO CARRY OUT AD/PHZL/60 A4. SUSPECT THAT THE COWLS WERE NOT CORRECTLY SECURED AFTER MAINTENANCE. PERSONNEL/MAINTENANCE ERROR.