Jabiru engines manufactured before July 2011 have reduced strength and reliability of the crankshaft/propeller flange joint, compared with the later design that incorporated positive location dowel pins.
The amendments should ensure the increased reliability of the propeller flange/crankshaft joint and the reduced likelihood of propeller loss due to joint fastener failure.
The current revision of the Jabiru Engine Overhaul Manual (document JEM0001-6) now includes a strong recommendation that owners update their engines during the next full overhaul or bulk strip, to include propeller flange dowels between the crankshaft and propeller flange - see Appendix A.
The ATSB is satisfied that the action to be taken by Jabiru should reduce the risk of design deficiencies with earlier (pre-engine SN 2446) crankshaft/ propeller flange assemblies.
