The Age Old Question

July 17, 2008
Are mandatory service bulletins really mandatory?

The question about mandatory bulletins has been around at least as long as I’ve been in this business. Although the guidance material out there continues to indicate conflicting positions within the FAA I think that the latest guidance makes it easier to determine the answer to the question “Is a mandatory service bulletin required for airworthiness compliance?” In this issue we will talk about what a service bulletin is and what the rules say about them being mandatory in the eyes of the manufacturer as well as the eyes of the FAA. Maybe we can come up with an answer that you will be able to hang onto for a while.

Let me start by making my personal position on this issue very clear. Compliance with mandatory service bulletins is one of the most important maintenance actions that an owner/operator can take to keep their aircraft in the safest and best possible condition. The manufacturer knows better than anyone else when special maintenance needs arise and the issuance of service bulletins is the chosen method for keeping us all informed. Not to mention what compliance with mandatory service bulletins can do for the resale value of the aircraft. My objective in this article is to help you understand the difference between the manufacturer’s highest level of suggestive maintenance (mandatory service bulletins) and the regulations.

Service bulletin
“Service bulletin” is a term that is used in our industry to describe notices that are sent out by equipment manufacturers to keep those who use and maintain the equipment aware of changes, errors, findings, new ideas, etc. It is an effective way for manufacturers to get information out to the market quickly. I’ve heard “service bulletins” called many things; service letters, customer bulletins, change notices, the list goes on and on. Each manufacturer has established its unique naming convention as well as numbering methodology. For the purposes of this discussion let’s just refer to them inclusively as service bulletins.

When manufacturers began issuing bulletins forever ago, I presume that they were just “bulletins” if only for a few months or years. But eventually the manufacturers must have realized that there were different levels of seriousness or criticality to a bulletin and began to further categorize them as recommended, optional, informational, mandatory, alert, etc. Having no standard for the terminology, it was left to the manufacturer to categorize the bulletins as they thought was best. The lack of standardization at least contributes to the confusion.

The evolution of the service bulletin, particularly in the business aviation community, has left us with a multitude of different types and different levels to hash through and try to make sense of. When the manufacturer attaches the term mandatory to a service bulletin, it’s human nature to ask the question, “Are mandatory bulletins really mandatory?” Or “What is mandatory anyway?” and look to the regulations for the answer. The manufacturer can categorize a service bulletin as mandatory, but where in the regulations does it say that service bulletins issued by the manufacturer are mandatory? Well, it doesn’t.

Airworthiness directive
Somewhere along the line, the FAA decided that a bulletin that had been issued by a manufacturer to correct a serious enough condition that operators needed to comply with the service bulletin, even though it was not considered “mandatory” by regulation, needed a new designation. It issued an airworthiness directive. 14 CFR Part 39 has been set aside for capturing all airworthiness directives issued by the FAA. This makes every airworthiness directive a regulation, and thus compliance becomes an issue of aircraft airworthiness. The distinction between mandatory and non-mandatory service bulletins is determined on a case-by-case basis and decided only by the FAA. Issuance of an airworthiness directive is one way that a service bulletin can be required by regulation. New guidance material issued by the FAA explains a few other ways that a manufacturer’s bulletin can become an airworthiness compliance requirement.

From the manufacturer’s perspective, mandatory always means important, even critical at times, but the FAA will only mandate compliance and make it into to an airworthiness directive if deemed necessary. So, the manufacturers need a way to make the service bulletin a permanent part of their inspection and maintenance program. A few of them have simply added a blanket statement as a line item in the inspection program for their aircraft that called for compliance with all service information (there are several variations of this). That approach has created more discussion than compliance, I think. Most manufacturers tie warranty coverage to mandatory service bulletins. For a new aircraft that is usually enough incentive for the operator to comply with all mandatory bulletins, but what about the older aircraft?

Making it mandatory
There is a way, however, for a manufacturer to mandate a service bulletin for all affected aircraft. Requirements called out or referred to in the Type Certificate Data Sheet (TCDS) or within the airworthiness limitations section of the aircraft maintenance manual are, without exception, regulatory. If the manufacturer adds the bulletin’s requirements to either that model’s TCDS or to the aircraft airworthiness limitations section of its maintenance manual, they will, in effect, be mandating those requirements. However, getting the requirement into the TCDS or the airworthiness limitations requires FAA approval and is not near as easy for the manufacturer as issuing a service bulletin and labeling it “mandatory.” Service bulletins are not regulatory just because the manufacturer says that they are mandatory. The FAA has provided an explanation in the form of an Advisory Circular and an FAA Order. I took some excerpts from both and have included them below.

From the FAA
Let’s first look at the FAA’s guidance for us — the industry. Advisory Circular 20-77A “Use of Manufacturer’s Maintenance Manuals” was issued in April of 2007 and really sums up what it takes for a service bulletin to be regulatory.

AC 20-77A Paragraph 6: The FAA recognizes that maintenance practices and requirements are not static and may change as information is developed during the service life of an aircraft. Manufacturers may provide a systematic manual revision system to implement changes to their maintenance instructions. Owner and operators should make allowances for such changes. The following is a list of situations when service bulletins (SB) would be regulatory and covers most situations ASIs encounter if: NOTE: For this section only, all references to manufacturer’s service bulletins will encompass all manufacturer’s service information.

  • All or a portion of a SB is incorporated as part of an airworthiness directive
  • The SB is part of the FAA-approved airworthiness limitations section of the manufacturer’s manual or the type certificate
  • SBs are incorporated directly or by reference into some type of FAA-approved inspection program, such as an Approved Aircraft Inspection Program (AAIP) or CAMP
  • SBs are listed as an additional maintenance requirement in the certificate holder’s OpSpecs

So, to be required by regulation, the service bulletin needs to be incorporated into an airworthiness directive (Reference 14 CFR Part 39) as discussed earlier, or part of the aircraft’s airworthiness limitations contained in the manufacturer’s maintenance manual or type certificate data sheet (Ref 14 CFR Part 91.409).

Airworthiness limitations
Airworthiness limitations are not discussed nearly as much as airworthiness directives. A quick explanation is warranted here. When an aircraft manufacturer receives type certification for a particular aircraft model or models they are also required to identify, in cooperation with the FAA, specific items on the aircraft that must be inspected or replaced periodically in order to ensure safety of flight. These items are the airworthiness limitations. In the text of the TCDS you will find reference to where the airworthiness limitations are listed. It is this “airworthiness limitations” listing that cannot be altered without FAA involvement and approval. In most cases the airworthiness limitations section of the maintenance manual is the only portion that is specifically FAA approved, usually ATA Chapter 4 or a separate document from the maintenance manual altogether. The manufacturer must also establish an “acceptable” inspection and maintenance program for the aircraft, usually found in ATA Chapter 5 of the aircraft maintenance manual. It is the portions of the maintenance manual that have not and in most cases do not, receive FAA approval that the manufacturer can make changes to without specific FAA approval.

The second two bullets listed from AC 20-77A apply to aircraft operated as an air carrier. Let me explain, AAIP’s are called for under 135.419, and a continuous airworthiness maintenance program is what is used for larger air carrier aircraft, (10 seats or more). An Operation Specification (OpSpecs), referred to in the last bullet item is required in order to operate as an air carrier. So service bulletins can also be mandated by way of air carrier regulations.

Required by regulation
Another reference document geared more toward the FAA safety inspectors clearly states that service bulletins must be required by a regulation in order to be mandatory. The document is FAA Order 8620.2A issued Nov. 5, 2007.

FAA Order 8620.2A paragraph 6(b): . . . although § 43.13(a) does not specifically address SB’s or SL’s, an OEM may legitimately incorporate an SB or SL into one of its maintenance manuals by reference. If it does so, the data specified, and the method, technique, or practice contained therein, may be acceptable to the Administrator. However, unless any method, technique, or practice prescribed by an OEM in any of its documents is specifically mandated by a regulatory document, such as airworthiness directive (AD), or specific regulatory language such as that in § 43.15(b), those methods, techniques, or practices are not mandatory.

Service bulletin references added to the manufacturer recommended inspection program for the aircraft are not mandatory unless they are tied specifically to a regulation. If the manufacturer wants to add a new requirement to its inspection program it can use its manual revision system to implement changes to its inspection program within the maintenance manual itself.

So, basically mandatory bulletins are just not mandatory on their own account. They must be supported further by some sort of airworthiness measure established or approved by the FAA. For any action to be mandatory in nature it must have a legal purpose. The regulations are written by the FAA to ensure that the aviation community stays within the boundaries of the actual law. For a service bulletin, or any requirement issued by the manufacturer for that matter, to be required for airworthiness compliance we must be able to trace it back to a regulation.

Joe Hertzler is the CEO and co-founder of Avtrak Inc., provider of the industry’s first Internet-based and compliance-focused maintenance tracking service — Avtrak GlobalNet. Avtrak has earned a solid reputation for having the most comprehensive and easy-to-use compliance management system and service in the industry. Avtrak’s GlobalNet technology is the engine behind Gulfstream and Sikorsky HelotracII. GlobalNet is the system of choice for many operators of more than 140 models including Bombardier, Hawker/Beechcraft, and Dassault Falcon aircraft.

About the Author

Joe Hertzler