One of the problems with the aviation rulemaking committee (ARC) process is that it gives people, and especially FAA lawyers, too much time to think. And too much thinking often leads to onerous interpretations of what seem like simple regulations.

A good example of this is a new proposed interpretation of 14 CFR Part 39, the rules governing Airworthiness Directives. Remember, if you don’t like the looks of this interpretation, the only way to put a wrench in the works is to make a comment (deadline May 16). You might also want to ask organizations of which you’re a member what they think; after all, that’s part of what you’re paying for when you join NBAA, NATA, ARSA, RACCA, AOPA, PAMA and AMTSociety.

The FAA recently published its proposed interpretation of the AD compliance process, in response to four questions raised by an ARC tasked with examining these issues. The issues came up as a result of the FAA’s plain language changes implemented in 2002. The ARC is the Organization/Procedures Working Group of the Airworthiness Directive Implementation Aviation Rulemaking Committee.

You can read the fascinating proposed interpretation in its entirety online, but to speed things up, here’s what looks to be the most worrisome aspect.

The fourth question addresses the issue of impossibilities in ADs, actions that cannot be done because, for example, a component to which the AD applies has been modified or removed during a modification. “A member of the AD ARC questions whether an AD needs to specifically address ‘impossibilities’ (for example, an AD requiring an action that is not possible for the specific aircraft to which the AD applies, such as modifying parts that have been removed during an earlier alteration).”

Here is the FAA’s reply to this question:

“Section 39.15. Does an Airworthiness Directive apply if the product has been changed?

“Yes, an Airworthiness Directive applies to each product identified in the airworthiness directive, even if an individual product has been changed by modifying, altering, or repairing it in the area addressed by the Airworthiness Directive.

“Section 39.17. What must I do if a change in a product affects my ability to accomplish the actions required in an Airworthiness Directive?

“If a change in a product affects your ability to accomplish the actions required by the airworthiness directive in any way, you must request FAA approval of an alternative method of compliance [AMOC]. Unless you can show the change eliminated the unsafe condition, your request should include the specific actions that you propose to address the unsafe condition. Submit your request in the manner described in Sec. 39.19.
“If a change to a product makes it impossible to comply with the requirements of an AD, then the operator must request an AMOC approval.”

This reply seems to raise serious issues, because the FAA interpretation suggests that even if an AD cannot apply because the modified item is completely different than the item called out in the AD, the FAA will still require FAA approval via an AMOC.

So essentially, the FAA seems to be saying that if a mechanic is looking up ADs for a particular aircraft and finds that an AD applies to a component that has been replaced with a new and different component, the mechanic can’t just note that the AD doesn’t apply. The mechanic will have to either prove that the unsafe condition that applied to the original component no longer exists or request an AMOC. An AMOC could involve some engineering, consultation with manufacturers and with extremely limited and overburdened FAA resources. It’s not hard to imagine such an approval request sitting on an FAA desk for weeks or months, effectively grounding the aircraft until an overworked FAA engineer can make a decision.

Question four of the proposed legal interpretation carries the potential of huge penalties for the aviation industry, if I’ve interpreted this correctly, that is. I am, after all, not a lawyer but an ordinary A&P. I think I can tell when an AD doesn’t apply and I believe most A&P mechanics would agree.

Incidentally, only one comment had been posted as of April 26: “This looks like there are a few FAA employees that don't have enough to do.” As apt as that comment might be, it will have zero effect on the FAA. And lack of any further comments will tell the FAA that it is on the right track with this interpretation and that the industry doesn’t care if this becomes de facto law.