Airworthiness Notice - B055, Edition 1 - 4 July 2000

Service Bulletin Compliance

The purpose of this notice is to clarify to Aircraft Maintenance Engineers and operators the need to comply with manufacturers' service bulletins, service letters, etc. 

Leaving aside publications made mandatory by airworthiness directives or equivalent mandatory notices issued by the airworthiness authority responsible for the initial type design of the product, manufacturers' publications may be considered under three general headings:

  1. Recommended methods and practices for the performance of work;
  2. Recommended modifications, inspections, and times between overhaul; and
  3. Mandatory actions established as part of the type certification process.

Although a single publication may in practice deal with more than one topic, in this notice each group will be dealt with separately:

  1. Publications specifying methods and practices for the performance of work
    Publications under this heading may be considered as amendments to the instructions for continued airworthiness (ICA).  As such, pursuant to Canadian Aviation Regulation (CAR) 571.02, they constitute one of three acceptable sources for such data (the other two are equivalent methods and standard industry practice).
  2. Publications recommending the incorporation of modifications, the performance of inspections, or times between overhaul
    Except where otherwise specified in Std 625, Appendix C, compliance with publications dealing with these topics is optional.  However, aircraft owners have a duty to be aware of the contents of these publications, and to evaluate the need for compliance in light of their own circumstances.  Commercial operators should have a formalized process for conducting this evaluation, as part of the evaluation program required by CAR 706.
  3. Publications providing information regarding airworthiness limitations established as part of the type certification process
    On occasion the communication of airworthiness limitations, such as component life limits or maintenance requirements is accomplished by referring to service bulletins or equivalent notices.  When used in this manner the content of the bulletin is a condition of the type certificate; and, except where Transport Canada has granted approval to deviate, compliance is mandatory.
    The above explanation should assist AMEs and operators in deciding on the need for compliance with service bulletins, service letters, etc.  Further guidance in individual cases may be obtained from Transport Canada Centres.
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