Introduction – Service Information the following is offered as a basic understanding of the typical documents we see issued by the Manufacture and OEM.
Maintenance Tip (MT) – Service Letter (SL) – Service Bulletin (SB) –Vendor Service Bulletin (VSB)
The term “service information” is used to encompass the various forms of notification that a manufacturer may use to communicate airworthiness information to owners/operators.
“Service Bulletin” is the common term and is often used in a generic sense; but there are also Service Letters, Service Information Letters, Service Notices, and so on. Manufacturers may also attribute a different weight or focus to each type of publication, in addition to applying different priorities.
Service information published by Vendor suppliers to aircraft manufacturer’s or product OEM’s is sometimes re-published by the aircraft manufacturer or product OEM.
The service information for the Vendor supplied items, regardless of whether published through the Vendor or the aircraft manufacturer or product OEM, must be assessed and actioned the same as the service information published by the aircraft manufacturer or product OEM.
Maintenance Tip (MT)
Maintenance Tips are used to clarify system operation along with providing techniques that benefit maintenance operations. Maintenance tips can also report on issues relating to processes and materials (grease, solvents, cleaners, etc.). They are issued for 7-series models except for 717, and are made available to customers through MBF.
Note MT – SL
A service letter usually has important information for all carriers while a maintenance tip can assist with troubleshooting. Sometimes the two may seem to serve the same purpose.
Service Letter (SL)
Service letters are used to provide information related to in-service issues, recommended changes to operating or maintenance practices, troubleshooting suggestions, information about future changes to the airplane, and resolution of issues related to airplane or component production. Service letters are made available to customers through MBF. (My Boeing Fleet)
Service letters are used to provide notification of upcoming changes to production aircraft, including the availability of a Boeing service bulletin or a supplier service bulletin for fleet retrofit/modification. Additionally, service letters are used to provide information related to new or preferred spares options.
Service letters do not in themselves authorize installation of parts or provide detailed procedures for modification, rework, repair, or inspection of an airplane. They serve as an information source and reference the appropriate approved change items such as a service bulletin or engineering drawing. An exception to these criteria is a service letter conveying minor changes necessary to correct a manufacturing error (to achieve airplane compliance with the engineering drawing) or changes to placards where there are no safety implications.
The heritage McDonnell Douglas Company product known as the All Operator Letter (AOL), applicable to DC-, MD-, and 717 model series only, has been replaced by the current Boeing service letter format.
Service Bulletins SB
SERVICE BULLETIN (SB) is a document issued by the manufacturer or Type Certificate Holder (TCH) to notify the owner or operator of an aircraft (or engine or other component or device) of recommended or in the case of an Alert Service Bulletin – (required action or activity (or may support actions, or inspections required by Airworthiness Directives) modifications, substitute parts, special inspections/checks, reduction of existing life limits or establishment of first-time life limits and conversions from one engine model to another. Service Bulletins may or may not be approved by regulatory authorities.
It is possible for a Service Bulletin to be adopt and made mandatory by the regulator of the state of the manufacturer.
Conversely it is also possible for a Service Bulletin to be written in support of a requirement generated through an AD
“Do manufacturers’ service bulletins or service information need to be complied with?”
Operators need to review all service information published by the manufacturer and action according to their type of operation, maintenance options, whether the instructions for continued airworthiness are affected, the type certificate is affected or whether it forms part of the maintenance schedule.
This review must be carried out by a competent person or persons and the outcome of the review must be recorded and signed for by the aircraft operator.
Vendor Service Bulletins VSB
Vendor Service Bulletins are issued by equipment or component manufactures, typically driven by reliability in service issues which are experienced by operators.
Just as with Service Bulletins, VSB may be the subject of Airworthiness Directive Actions.
Whilst a full awareness of the reasons for Vendor Service Bulletins should be understood by the Continuing Airworthiness Management Organization ,Typically VSB are considered when a component is removed as defective.
Some VSB’s are know as soft bulletins, for example they may be placed against an engine but not performed until the engine is removed from wing which could be some years.
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Tags:
Maintenance Tip, OEM, SB, service bulletin, Service Information Letters, Service Letter, Service Letters, Service Notices, Vendor Service Bulletin
