On 17 March 2017, uncommanded engine indications on a Saab 340B en route to Sydney were followed by vibration of the right engine after which, as the crew commenced right engine shutdown, its propeller assembly separated from the engine. A PAN was declared and the flight subsequently reached Sydney without further event. The Investigation found that the propeller gearbox shaft had fractured because of undetected internal fatigue cracking in the shaft. Applicable in-service shaft inspection procedures were found to be inadequate and mandatory enhancements to these procedures have since been introduced.