Additive Manufacturing and Aerospace Maintenance Continued from page 67 THE FIRST THING THAT COMES TO A FORMER REGULATOR’S MIND IS THE EASE IN WHICH 3-D PRINTING COULD ALLOW FOR PRODUCING COUNTERFEITING PARTS. flexibility, agility, and cost-savings from additive manufacturing.1 Yet, given the uncertainties sur- rounding such rapid change, the industry and, more so, the Federal Aviation Administration’s (FAA) acceptance2 of AM has been cautious because of the safety and reliability implications. Nevertheless, with the fast prototyping of parts and many other applications, AM is expanding at a pace that is fast, even for aviation. As newly-designed parts make their way to the actual aircraft, the 1 http://web.stratasys.com/rs/objet/images/ SSYS-WP-AeroTrends-03-13-FINAL.pdf 2 http://www.nianet.org/ODM/ODM%20 Wednesday%20presentations%20Final/7%20 Kabbara%20On-Demand%20Workshop%20 AM%20Presentation(03-09-2016.pdf technological possibilities are only just beginning to be realized. For instance, manufacturers experiment- ing with new materials and optimized designs (made possible by AM) are achieving improved design and production of jet engine fuel nozzles. Other engine manufacturers are using AM capabilities to make blades and vanes for engine compressors. Many airframe manufacturers and suppliers are using AM to produce many less safety-critical parts, such as seat-back trays and armrests. It’s clear that a big attraction of additive manufacturing is the benefit to the bottom line due to the flex- ibility in design, lower developmental costs, lower material and labor costs, and increasing availability of parts. For example, instead of machin- ing components from solid metal, in which much of the material is cut away, only the material that is needed to shape the part is used, thus reducing production waste. Another AM benefit is the ability to target the manufacturing location. The 3-D printers can be set up almost anywhere, eliminating or greatly reducing the costs of shipping and warehousing and reducing a manu- facturer’s environmental footprint. Yet, as Kermit famously said, “It’s not easy being green.” There are necessary process controls and speci- fications to ensure that the new AM parts conform with current, or even new, production standards. This has long been a challenge for the regula- tor—keeping up with technological change—but this change is even more accelerated. The existing regulatory certification standards are based on scientific assumptions about how manufacturing techniques, such as machining, heat treating, and forging can have on materials, including dam- age tolerance and fatigue. In the AM process, more needs to be understood about the alloys or their mechani- cal properties. Furthermore, there is no FAA standard for using powder, which is the common ingredient in the AM process. In circumstances where AM processes use the same material as traditional processes (e.g., using 2024 aluminum powder versus a part forged or machined from solid 2024 aluminum) should the parts be considered equivalent? Those are just some of the ques- tions to be addressed. There are many more, such as, “What about continued airworthiness with regards to inspection, reparability, and counterfeit part control and detec- tion?” The first thing that comes to a former regulator’s mind is the ease in which 3-D printing could allow for producing counterfeiting parts. In the near future, part marking and new ways of injecting unique identifiers into the process will need to be examined. The process used to detect suspected unapproved parts may also need to be reviewed. Certainly, the reporting methods we use today will continue to support the detection of unapproved and counter- feit parts; but, the industry will have to get smarter at distinguishing an approved AM part from a counterfeit one. Training for technicians, distrib- utors, and aircraft owners will need to be updated as a method of prevention. 68 Aviation Business Journal | 1st Quarter 2017
