Are Service Bulletins Mandatory or Not?!
I’ve been asked an age-old question several times recently: “Are service bulletins mandatory?” There are as many opinions about this question as there are FAA safety inspectors (but I encourage you to know the answer to this question without asking your FAA inspector). It truly depends on the service bulletin itself and the rules to which it relates. Each bulletin can be different in that regard. This article aims to provide you with enough information to be able to answer the question yourself.
Firstly, we need to define what “mandatory” means. For the purposes of this discussion, the term mandatory means “required in order to maintain a valid FAA airworthiness certificate.”
Most service bulletins are not mandatory in nature as defined above. Each manufacturer, whether it be an airframe, engine, propeller or appliance manufacturer, has some method of notifying the industry when conditions that need to be addressed exist. Most manufactures have more than one level of seriousness or urgency associated with their bulletins. They can be labeled informational, recommended, mandatory, alert, etc. This might be a source of confusion. When the manufacturer says the bulletin is “mandatory,” the definition of mandatory gets cloudy. If the manufacturer states that the bulletin is mandatory, they want you to comply with it and there might be some warranty issues attached to it. Not complying with a bulletin could have consequences from the manufacturer, but the fact that the manufacturer states that the bulletin is mandatory doesn’t mean that it is “required in order to maintain a valid FAA airworthiness certificate.” This is an important distinction. By FAA design, the manufacturer does not have specific authority to mandate an action except through certain channels, all of which are regulatory and FAA governed. Below we will discuss the channels through which compliance with a service bulletin can be mandatory.
The Aircraft Type Certificate Data Sheet issued by the FAA
The airworthiness of an aircraft begins at the type certificate data sheet (TCDS). That is where the FAA defines the type design of an aircraft, and in order to be airworthy, an aircraft must conform to its type design (or its properly altered configuration, i.e., STCs), and be in a condition for safe operation. That’s where I start when digging through these types of questions. The TCDS defines the aircraft in several ways.
Every manufacturer differs in how they handle some of the key elements of what is addressed in a TCDS, but they all give us critical airworthiness data. The TCDS tells us where to find airworthiness limitations, which are those inspection and maintenance items and life-limited parts. Some manufacturesr place the airworthiness limitations in the aircraft maintenance manual itself. In those cases, you will see that the FAA has approved that section of the maintenance manual. In other cases, the airworthiness limitations might be a separate document itself — not the maintenance manual or a service bulletin, but a completely separate document.
Some manufactures place the airworthiness limitations in service bulletins. In those cases, those bulletins are indeed mandatory because they are then the source document for the replacement times for life-limited parts called for in 14 CFR Part 91.409(e). Because 91.409 (e) requires life-limited part replacement times be complied with (see below), and a manufacturer can choose to use a service bulletin to define those replacement times, a service bulletin that calls for them AND is referred to in the TCDS must be complied. There are no other options.
14CFR Part 91.409 Inspections
(e) Large airplanes (to which Part 125 is not applicable), turbojet multiengine airplanes, turbopropeller-powered multi-engine airplanes, and turbine-powered rotorcraft. No person may operate a large airplane, turbojet multi-engine airplane, turbopropeller-powered multi-engine airplane, or turbine-powered rotorcraft unless the replacement times for life-limited parts specified in the aircraft specifications, type data sheets, or other documents approved by the Administrator are complied with and the airplane or turbine-powered rotorcraft, including the airframe, engines, propellers, rotors, appliances, survival equipment, and emergency equipment, is inspected in accordance with an inspection program selected under the provisions of paragraph (f) of this section, except that, the owner or operator of a turbine-powered rotorcraft may elect to use the inspection provisions of § 91.409(a), (b), (c), or (d) in lieu of an inspection option of § 91.409(f).
For example, Pratt and Whitney TCDS E4EA, Revision 26, dated Dec. 21, 2012, includes the following:
Note 14: Certain engine parts are life limited. These limits are listed in P&WC Engine Service Bulletin Nos. 1002, 1302, 1402, 1602, 3002, 4002, 12002, 12102, 13002, and 13202 as revised. PT6A-140 refer to AWL section of the maintenance manual P/N 3075742.
Another example is Honeywell TCDS E6WE, Revision 17, dated May 9, 2000, which states the following:
Note 9: Certain engine parts are life-limited. These limits are listed in the FAA approved Honeywell International Inc. Service Bulletins TFE731-72-3001 and TFE731-72-3501.
These notes contained in the TCDS makes compliance with those bulletins mandatory due to the regulation that calls for them to be complied with. Take the time to look through the TCDS that are applicable to your aircraft and its attached Class I components (engines and props) and you might find that there is a service bulletin that calls out the life-limited parts that must be replaced as defined in order to maintain the aircraft’s airworthiness.
FAA Airworthiness Directive Reference
Another means by which a service bulletin can be mandatory is much more common to everyone. It is through an airworthiness directive, which the FAA (and other governing agencies worldwide) issue for the purpose of mandating specific actions be taken in order to ensure safe operation of aircraft. In most cases, those actions are the result of a previously-issued manufacturer’s service bulletin. The manufacturer issues the bulletin (usually with some level of urgency) and then submits it to the FAA for review. The FAA will then decide whether or not the need or condition addressed by the service bulletin warrants an airworthiness directive (AD). If it does, the FAA will then issue an AD and in the language of the AD specifically refer to the service bulletin and its contents for detailed actions to be taken. There are certainly problems with this process. The author of the AD will often call for a specific revision of a service bulletin to be accomplished. Then when the manufacturer revises the service bulletin, the FAA doesn’t revise the AD and the AD calls for compliance with an outdated service bulletin. We have run into this issue many times.
The Current Inspection Program Recommended by the Manufacturer
The third and most elusive way in which a manufacturer’s service bulletin can be mandatory (as defined within this article), is a “gotcha.” You see, 14 CFR Part 91.409 goes on to say in paragraph (f): (the key points in bold italics)
14 CFR Part 91.409 Inspections
(f) Selection of inspection program under paragraph (e) of this section. The registered owner or operator of each airplane or turbine-powered rotorcraft described in paragraph (e) of this section must select, identify in the aircraft maintenance records, and use one of the following programs for the inspection of the aircraft:
(1) A continuous airworthiness inspection program that is part of a continuous airworthiness maintenance program currently in use by a person holding an air carrier operating certificate or an operating certificate issued under Part 121 or 135 of this chapter and operating that make and model aircraft under Part 121 of this chapter or operating that make and model under Part 135 of this chapter and maintaining it under §135.411(a)(2) of this chapter.
(2) An approved aircraft inspection program approved under §135.419 of this chapter and currently in use by a person holding an operating certificate issued under Part 135 of this chapter.
(3) A current inspection program recommended by the manufacturer.
(4) Any other inspection program established by the registered owner or operator of that airplane or turbine-powered rotorcraft and approved by the Administrator under paragraph (g) of this section. However, the Administrator may require revision of this inspection program in accordance with the provisions of §91.415.
The most common inspection program in use in corporate aviation is the (f)(3) option, the current inspection program recommended by the manufacturer. Prior to 2005, it was interpreted and expressed through FAA internal guidance documents that the inspection program recommended by the manufacturer did not include service bulletins or service information until such time as that information was incorporated into the details of the inspection program itself. It was during a revision to the then FAA Order 8300.10 (later changed to 8900.1) that a change was made. The FAA now interprets this to mean that whenever a service bulletin is issued by the manufacturer that includes inspection, that service bulletin is incorporated into the manufacturer’s recommended inspection program and, if the operator has selected the current inspection program recommended by the manufacturer, the operator must accomplish it as written. Below is an excerpt from FAA order 8900.1. The wording seems backhanded because it implies that all service bulletins were at one time interpreted to be required. However, that is not the case. Before this language was introduced somewhere around 2005 or 2006, service bulletins were clearly excluded. The previous language was as follows: NOTE: Because this program addresses inspections only, it does not include Service Bulletins (SB), Service Letters (SL), service instructions and other maintenance documents.
Below is the current FAA interpretation and enforcement guidance relative to service bulletins and inspections. I have included more than just the service bulletin reference for context. It can be found in its entirety at the following web location:
8900.1 CHG 239, dated 1/2/13
VOLUME 6 SURVEILLANCE
CHAPTER 1 PART 91 INSPECTIONS
Section 2 Monitor Part 91 and Approve/Monitor a Part 91 Subpart K Program Manager’s Aircraft Inspection Program
C. Large Airplane (Over 12,500 Pounds (lbs)) and Turbine-Powered (Turbojet and Turbopropeller) Multi-engine Airplane Inspection Programs. These aircraft must be inspected according to the requirements of an inspection program selected by the owner/operator/program manager. Section 91.409(f) ...
2) Reference to a manufacturer-recommended program has led to several misconceptions about what precisely constitutes such a program.
a) Section 91.409(3) refers to “A current inspection program recommended by the manufacturer.” No reference is made to the aircraft manufacturer specifically; § 91.409, however, requires inspection of the airframe, engines, propellers, appliances, survival equipment, and emergency equipment.
b) Therefore, a complete manufacturer’s recommended program consists of the program supplied by the airframe manufacturer and supplemented by the inspection programs provided by the manufacturers of the engines, propellers, appliances, survival equipment, and emergency equipment installed on the aircraft.
NOTE: Because this program addresses inspections only, it does not include Service Bulletins (SB), Service Letters (SL), service instructions, and other maintenance documents, unless they require an inspection to be performed.
In summary, there are only a few ways that a service bulletin can be required in order to maintain a valid FAA airworthiness certificate — or mandatory.
• As a means of calling out life-limited parts through reference in the TCDS
• By reference as an AD
• Or when the service bulletin requires an inspection to be performed. (I don’t like this one, but that is the FAA’s position)
For certificated air carriers, service bulletins can also be required through the operations specifications for the certificate, but for the purposes of a Part 91 operator, this sums it up.
All that being said, the safety of the aircraft is the first and most important priority. It is my personal recommendation that whenever the manufacturer issues a service bulletin that is applicable to your aircraft, that you comply with it and incorporate those changes as soon as possible. Nobody knows the aircraft better than the manufacturer. These days, the FAA is not the only consideration for compliance. Some insurance policies and purchase agreements are getting much smarter and including language around service bulletins as well rather than just the blanket “airworthy” statement.
I hope this has been helpful. It can be a controversial topic, but that is only because of the many ways that service bulletins are used. Until next time ...
Joe Hertzler has more than 25 years of experience in business aviation. He has earned a reputation as an efficiency expert when it comes to aircraft maintenance and is well known for his in-depth understanding of maintenance regulations and how they affect aircraft compliance. He has helped many in dealing with critical and urgent FAA interactions and often speaks on the topic of aircraft maintenance and compliance at industry events, such as the NBAA Maintenance Managers Conference, PAMA meetings and IA renewal seminars. Hertzler also serves on the National Air Transportation Association’s (NATA) Maintenance and Systems Technology committee. Contact him at JoeHertzler@gmail.com.