Part 43: Our Rule: Written by mechanics for mechanics

Of the 199 Parts and a zillion words that make up FAA regulations in Chapter 1 of Title 14, Aeronautics and Space in the Code of Federal Regulations, only one Part speaks solely to us


Necessary tools, equipment

The second requirement of this paragraph requires the mechanic to have the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If any special equipment or test apparatus is recommended by the manufacturer, the mechanic must use that equipment or apparatus or its equivalent acceptable to the Administrator.

OK, this paragraph says a mechanic has to have the right tools or test equipment to do the work. Now back when I had calluses on my hands and I could part my hair, my lower toolbox drawer had all kinds of "special tools." Over 99 percent of them were box or open end wrenches that were modified by hammer, torch, and bench vice to extreme angles that allowed me to get a bite on that elusive nut or fitting buried behind an unmovable object in an inaccessible location.

However, the rule is not speaking to those kinds of mechanic modified tools. What the rule is talking about when it uses the word "equivalent" is the other 1 percent of the tools each of us has stashed in our toolboxes or tool rooms. You know the one; it’s the wind-driven counter-clockwise safety wire twister that you made for $99.95 that is the "equivalent" of the $1,499 nuclear powered counter-clockwise safety wire twister that is called out in page 187 of the manufacturer’s maintenance manual as the tool to be used to safety wire the frazzlebath valve on the main auxiliary biofeed transfer pump.

Since it is the mechanic or certificated organization who determines if the "home designed special tool" is equivalent to the manufacturer’s "special tool," it is in your own best interest to have something down in writing on how that determination of special tool equivalency was determined, when it was determined, and who determined it. Also, if the "equivalent" special tool requires some sort of calibration, the calibration times and standard to be used should also be noted in the mechanic’s documentation or company’s manual. I am offering you this advice so you can have a better answer than I had when I had to answer those embarrassing questions from an FAA inspector who just happened to notice one of my special tools peeking out of the lower drawer of my toolbox.

Equal to the original, not better than

Paragraph (b) of the rule is where an often repeated maintenance myth began. The paragraph starts off by saying that each person maintaining or altering or performing preventive maintenance shall do that work in such a manner and use materials of such a quality that the condition of the aircraft will be at least equal to its original or properly altered condition. When I went to A&P school, the instructors always told us that if you do the work at least equal to or better than, the original, then the FAA can’t write you up. But the rule does not say "better than." Besides, if you repair a part by making it better than the original, you have in fact altered it. So stick with "equal to" and send "better than" to your memory’s recycle bin. The paragraph also uses the words "properly altered condition." This is speaking to the three ways you can alter a Type Designed product. They are Supplemental Type Certificate (STC), Airworthiness Directive (AD), or FAA Field Approval. So if you have to do a repair on a PMA part that is part of an STC you have to get the data from the STC holder or other approved source.

Follow the manual

Paragraph (c) allows Part 121, 129, and 135 operators respite from paragraphs (a) and (b) of the rule and instead requires them to meet the performance requirements spelled out in their operating limitations and manual. Not fair, you say! We give the big boys relief from meeting manufacturer’s manuals and Instructions for Continued Airworthiness requirements and the work does not have to be "equal to" the original or properly altered condition. Not so! In reality, air carriers are held to a much higher standard of performance than Part 91 operators because they have to meet the requirements in their continuous airworthiness maintenance manuals and other special requirements found in their operating limitations. To ensure that the big boys do not take a sabbatical from complying with the regulations, the FAA headquarters has ensured that each FAA certificating managing office (CMO) and the air carrier are joined at the hip just to prevent that from happening.

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