Rex - Regional Express (ZL, Wagga Wagga) has announced it has grounded five Saab 340Bs following an incident last week in which a prop on-board VH-NRX (msn 291) detached while in mid-flight.

The aircraft was en-route from Albury to Sydney Kingsford Smith on Friday, March 17, with sixteen passengers and three crew on-board when the starboard propeller sheared off. An emergency was declared with the aircraft making a safe landing at Sydney Kingsford Smith.

While the Australian Transport Safety Bureau (ATSB) and the Civil Aviation Safety Authority (CASA) carry out their investigation into the incident, REX says it has withdrawn all other aircraft in its fleet that feature the same variant of General Electric CT7-9B powerplants as those of VH-NRX.

"While waiting for the ATSB to determine the root cause of the incident through its metallurgical analysis and other investigations, REX has decided, by abundance of caution, to immediately remove from service and quarantine all Propeller Gear Boxes and shafts of the same series as that of the incident for further inspection and testing if warranted," it said in a statement.

According to the ch-aviation aircraft database, REX operates thirty Saab 340Bs and twenty-one Saab 340B(Plus) with a collective average age of 23.1 years.