Jabiru Aircraft last week issued a mandatory service bulletin to replace crankshafts in their six-cylinder 3300 engines.
The company says it has identified a potential problem with a batch of crankshafts fitted to engines built between April 2017 and June 2024. The six-cylinder engine is fitted to a number of aircraft models including the Jabiru J-230 and J-430.
"At Jabiru, safety is non-negotiable," said Jabiru Director Michael Halloran. "Our commitment to our customers extends beyond the sale – we want every Jabiru engine to deliver reliable performance throughout its entire service life.
"This service bulletin reflects our dedication to continuous improvement and our responsibility as an OEM."
Jabiru engineers discovered the issue after a small number of in-service engine failures, that resulted in no injuries.
"While analysis indicates the overall risk of failure remains low, the potential for engine stoppage necessitates a conservative approach to ensure continued flight safety," the company has stated.
Jabiru is asking all owners of affected engines to contact the company with their engine's time in service, after which the company says it will prioritise customers based on risk.
Crankshafts will be replaced over 2025-26 for engines with a total time in service exceeding 150 hour at no component cost to the customer.
According to Jabiru, Service Bulletin JSB046 is part of their Operation Bulletproof initiative, which aims to increase the reliability and serviceability of their engines.
Jabiru has already made a change to manufacturing, reverting to a process where crankshafts are now machined from imported billets. This allows for the material properties to be tested before production starts.