Individuals performing maintenance under Part 43 must often decide whether maintenance instructions are mandatory or simply recommended.  It’s a critically important decision.  The failure to use required maintenance techniques/practices raises a host of potential FAR violations, and in some circumstances, raises the potential for criminal liability.  Moreover, as discussed in our blog post exploring a recent FAA Office of Chief Counsel opinion on who may be held responsible for improperly performed maintenance, the threat of civil/criminal liability for improper repairs, extends far beyond just the mechanics who approve the work performed.

One of the most commonly misunderstood regulations is the general performance rules of FAR 43.13(a) which provides:

“Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer’s maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16….”

This regulation is commonly misinterpreted by mechanics, customers, and sometimes even FAA inspectors to mean . . .  “if it’s in the CMM, its required.”  Although the text of FAR 43.13(a) provides that the person performing maintenance “shall” use the maintenance manual, an alternative is provided in the same sentence, i.e., by virtue of the “or”, the person may use “other methods, techniques, and practices Acceptable to the Administrator…” While the FARs do a poor job of explaining what “acceptable to the Administrator” actually means, the regulations clearly permit other maintenance techniques and practices beyond just what’s in the CMM.

One exception to allowing other practices acceptable to the Administrator under this rule, is maintenance/inspection specified in an Airworthiness Limitations Section of a manufacturer’s maintenance manual (FAR 43.16).  This rule permits only maintenance in accordance with the instructions in that section of the manual, and does not allow for other maintenance practices and techniques acceptable to the Administrator.  In fact, FAR 43.16 unambiguously states that the person performing maintenance in the Airworthiness Limitations Section of a maintenance manual “shall perform” the inspection/maintenance in accordance with that section.  Seems pretty clear, right?

Maybe not.  The FAA Office of Chief Counsel has graced us with another legal opinion on maintenance performed under Part 43.  This time, the FAA Chief Counsel’s Office was asked to provide an opinion on whether a properly qualified airframe mechanic who performs Airworthiness Limitation required maintenance in accordance with FARs 43.13 and 43.16, would be in violation of any rule if they did not comply with the training and authorization requirements prescribed by the manufacturer in the Airworthiness Limitations Section of their maintenance manual.

At issue were instructions in the Airworthiness Limitations Section of the maintenance manual which required that maintenance only be performed by technicians who had received special training/authorization from the manufacturer.

While acknowledging that a literal reading of FAR 43.16 requires compliance with a manufacturer’s Airworthiness Limitations Section of the maintenance manual, the FAA goes on to clarify that those regulations are directed to the proper performance of maintenance, not to who may perform it.  The opinion explains that the manufacturer imposed limitations on who may properly perform maintenance in the Airworthiness Limitations Section of a maintenance manual goes beyond what is required and intended by the FARs, and is unenforceable from an FAA regulatory perspective.

In other words… “shall” doesn’t actually mean “shall” — at least not in the context of restrictions on who may properly perform Airworthiness Limitations Section maintenance under FAR 43.16.

The takeaway here is that, as long as the technician is properly rated and qualified under the FARs to perform the Airworthiness Limitations Section maintenance, any manufacturer imposed requirements/mandates that go beyond FAR qualification requirements, are discretionary and unenforceable from a regulatory perspective.

The opinion serves as a useful reminder that the FARs define the scope of an MRO facility’s regulatory requirements — not the manufacturer, and that just because the manufacturer says its required, doesn’t mean it always is.

(Originally posted June 18, 2014)