As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING AN AIRWORTHINESS CONDITION CHECK, IT WAS DISCOVERED THAT A RIVET HEAD FOR THE TTO SENSOR ATTACHMENT MOUNT IN THE #1 ENGINE INLET HAD DEPARTED. ONLY ONE OF THE FIVE TOTAL WAS FOUND MISSING THE HEAD, THE AIRFRAME AND ENGINE HAD A TOTAL OF 3029.3 HRS ON THEM AND 2669 CYCLES. THE RIVET WAS REMOVED AND REPLACED. (TC# 20150811007)