Dealing with manufacturers service bulletins – proposed under Part 43

Learn more about dealing with manufacturers service bulletins once Part 43 is made and commences.

Who should read this

  • Licensed aircraft maintenance engineers
  • Registered Operators
  • CAR30 organisations
  • Part 145 Approved Maintenance Organisations

What is a service bulletin?

Manufacturers publish many forms of maintenance related information such as Service Bulletins (SB) and Service Instructions (SI). These documents typically contain information that supplement a manufacturer's published maintenance manual or instructions for continuing airworthiness ICAs.

When is compliance with manufacturers' service bulletins compulsory?

With some exceptions SBs are non-binding on registered operators (RO) of aircraft engaged in private and aerial work operations unless an SB has been mandated by an Airworthiness Directive (AD) or another rule.

Are there other instances when compliance with a service bulletin is required?

The following outlines instances when compliance with the prescribed intervals of a SB would be mandatory:

  • all or a portion of an SB is incorporated as part of an AD
  • the SB is incorporated directly or by reference into an approved inspection program
  • the SB is part of the approved Airworthiness Limitation Section (AWL) of the manufacturer's manual or the type certificate (TC). However, compliance with a new or revised AWL issued by a design approval holder (DAH) or other entity as a type design change, is not mandatory for in-service aircraft being maintained under Part 43, unless it is mandated by one of the other situations above. In other words, changes to AWLs are not retrospective unless mandated by the certifying NAA or CASA
  • in the absence of any such direction, ROs can elect to comply with the new or revised limits voluntarily.

Do service bulletins amend manufacturers ICAs?

No, the MTPs set out in the manufacturers ICAs that are current for the aircraft are the MTPs to be observed by a maintainer unless otherwise directed by CASA.


The content provided in the information sheet is a guide only as to how the rules may work in practice once Part 43 is made and commences.

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