EASA SIB 2019-18
CFM International CFM 56-7B Engines - Fan blades — Life Limitation
Summary
EASA Safety Information Bulletin 2019-18 is an informational document addressing fan blade life limitations for CFM International CFM56-7B engines, which are installed on Boeing 737-600, 737-700, 737-800, and 737-900 aircraft. The bulletin discusses reported fan blade failures due to fatigue fractures and references related service bulletins and EASA Airworthiness Directive 2019-0018. It provides recommendations to enhance safety by implementing fan blade life limits but does not impose mandatory requirements.
What Changed
The bulletin introduces recommended fan blade life limits for CFM56-7B engines to reduce the risk of fan blade cracks and failures. It supplements the existing inspection program mandated by EASA Airworthiness Directive 2019-0018 by providing guidance on estimating fan blade cycles when unknown. However, it does not mandate these life limits as regulatory requirements.
Why It Matters
This information is important for aviation professionals because it highlights a potential safety risk related to fan blade fatigue in widely used CFM56-7B engines. Operators and maintenance organizations can use the recommended life limits to proactively remove susceptible fan blades, thereby enhancing fleet safety and potentially avoiding uncontained engine events. Compliance teams should be aware that while the recommendations are not mandatory, following them can improve safety margins.
What To Do
Operators and maintenance providers are advised to remove fan blades before exceeding the recommended life limits specified in CFM International Service Bulletin CFM56-7B S/B 72-1050. They should also avoid installing spare fan blades that have surpassed these limits. No new mandatory compliance deadlines are imposed by this bulletin, but adherence to the recommendations is encouraged to improve safety.