In addition, the use of nonde- structive testing (NDT) on AM parts is another industry challenge and concern for the regulators. Many of the existing NDT or nondestructive evaluation (NDE) standard pro- cedures applied to conventionally wrought, forged, and molded metal components are generally applicable to parts made by AM. Nevertheless, there are still specific challenges for conducting NDT, particularly regard- ing the lack of documented and shared fracture toughness, fatigue strength, and other key properties for AM metals. This is compounded by the potential for differences between 3-D machine printing characteristics, feed stock variations, and the large processing parameter differences that come with AM production. The FAA in concert with industry will also need to review mainte- nance regulations to determine if existing regulations are sufficient to address inspection and repair of AM parts. For example, consider 14 CFR Part 43, specifically §43.13, which requires all maintenance be performed in such a manner, and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appli- ance worked on will be at least equal to its original or properly-altered condition. Compliance with existing regulations must be demonstrated whether a part is being maintained or altered using AM technology or traditional/conventional methods. Finally, as a former Aviation Maintenance Technician, I see a big benefit of 3-D printing–the ability to print your own tools. Think about that for a minute, all the money one could save with a one-time invest- ment in a high-end printer. That would certainly give Snap-on tools a run for their money! In all serious- ness, there is no doubt that special tools required and available for pur- chase from the original manufacturer will be produced using AM. So, when a special tool is required by the manu- facturer’s maintenance instructions and you decide to make your own, how will you as a maintainer, repair station, or other, determine equiva- lency—especially if you are going to make it the good old-fashioned way using metal components and mill- ing, and so forth? Is there a direct 1:1 comparison between a 3-D-printed tool and one made in a back shop? The FAA and industry have formed work groups to look at the regulatory and process gaps in the design and certification of AM parts versus con- ventional parts. In addition, ASTM International has multiple teams reviewing and developing standards to define terminology, measure the performance of different production processes, ensure the quality of the end products, and specify procedures for the calibration of AM equipment. Just like any other new technol- ogy, there is always a huge learning curve. I always like to remember that we have more computing abil- ity in our smart phones than was available for Neil Armstrong’s one small step on the moon. The same will be said for AM and other new technologies in the not-so-distant future. When we fly on airplanes WHEN WE FLY ON AIRPLANES THAT ARE PRINTED FROM A MACHINE USING TITANIUM POWDER, AND WORK ON AIRCRAFT PARTS WITH OUR 3-D PRINTED TOOLS, THEN WE WILL BE SHAKING OUR COLLECTIVE HEADS AND WONDERING HOW WE EVER GOT ALONG WITHOUT THEM. that are printed from a machine using titanium powder, and work on aircraft parts with our 3-D printed tools, then we will be shaking our collective heads and wondering how we ever got along without them. Aviation Business Journal | 1st Quarter 2017 69
