There are two maintenance questions that are posed to me again and again: First, “Are Mandatory Service Bulletins really mandatory?” and it’s counterpart: “When the manufacturer updates the maintenance program, do I have to comply with the changes?” The owners of N-registered aircraft keep asking because the actual answers are ambiguous, and depending on the procedure involved, the “just do it” option of compliance can be awfully expensive.
Mandatory Service Bulletins: Under FAR Part 91, if a manufacturer issues a new “mandatory” Service Bulletin, a Part 91 aircraft operator is not required to follow the SB. However, should that bulletin later become an FAA Airworthiness Directive, then compliance becomes required at that time.
Current Inspection Program Recommended by the Manufacturer: Owners and operators of large and turbine aircraft must follow an inspection program in accordance with Part 91.409. Most of those Part 91 owners and operators elect to follow a “current inspection program recommended by the manufacturer” under Part 91.409(f)(3).
The word “current” causes confusion. Numerous FAA Legal Interpretations have clarified that the agency holds the word “current” to mean the program as it existed at the time the operator or owner adopted it. So, if you purchase a 2005 aircraft in 2010, the “current” inspection program to follow would have been the one that existed in 2010. Once you select the current inspection program under Part 91.409(f)(3), that program remains the one you must follow regardless of any revision the manufacturer makes subsequently – unless the revision is mandated by an FASS-issued AD or other FAA rule.
So, a “mandatory” Service Bulletin could be part of your current inspection program if, at the time that you adopted the program (that is, when you purchased your aircraft) any Service Bulletin(s) that contain inspection requirements are included, whether they appear directly in the program or are incorporated into it by reference...
