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Additive manufacturing (AM) – more commonly known as 3D printing – promises to revolutionize manufacturing processes around the world and offers aviation new opportunities to create stronger, lighter structures, for both the airframe and the cabin. AM is slowly but surely moving now from ideation, prototyping to the in service market for airline interiors utilizing both metal and polymer printing. Polymer plays a bigger role at the moment as the Metal parts are more critical and the certification and approval process’s more tedious.
Vinu Vijayan who is the Global Business Development Manager, Aerospace for EOS recently spoke at a Webinar focussed on Airline Interiors organised by Red Cabin, indicated that "the drivers for Additive Manufacturing adoption in Airline interiors can be divided into two levels – one at the component or part level and the other at the supply chain level."
Drivers - Component Level
When deciding which part to begin making with additive manufacturing, thinking beyond individual parts is key. The design freedom that comes with manufacturing production parts with an industrial 3D printer can revolutionize the way interior aircraft parts are created.
For example consider a fan that is part of a cooling system, contains 73 metal parts that must be hand assembled and takes days to make just a few completed parts. This fan can be designed for additive manufacturing (DfAM) and consolidate the 73 parts down to one. This reduces assembly time, possible failure points, and hundreds of parts can be made on an industrial 3D printer in the same time it takes to hand assemble the original part. Another example is the generatively designed rocket combustion chamber by Hyperganic where EOS did the generative design-to-print workflow.
In other words Additive Manufacturing allows minimizing manufacturing implied constraints at design level and helping to achieve increased performance with lighter and cheaper parts.
In addition, leveraging DfAM skillsets enables these parts to support compact packaging by better utilizing the available volume within a confined space. Designing additive manufactured parts that are printed instead of injection-molded or manufactured using a CNC machine creates endless possibilities with interior aircraft parts. Positioning features and subtly changed designs do not add additional tooling cost, rather it is a simply a second part number that can further optimize system performance rather than utilize the best average design. Internal channels or angles that previously had to be assembled can now be integrated for a streamlined manufacturing process. Another example is the Latch shaft for A350 door by Airbus Helicopters. Embracing complexity, functional integration and customization are the key advantages of Additive Manufacturing at a component level.
Drivers - Supply Chain Level
Additive Manufacturing enables airline companies the option to have a truly flexible and optimised production. Once scalability has been solved for, deciding the best location to manufacture helps reduce delivery time and keeps aerospace companies competitive. Additive manufacturing can be networked across several countries and factories to produce and deliver locally.
Weight and consolidating multiple parts into one, additive manufacturing of production parts allows for easy scalability from prototype parts into full-scale manufacturing. Prototyping without the vision and expertise to eventually go into full-scale production is wasting time and money. Leveraging expertise of additive manufacturing, design engineers at the prototype stage ensure that a product is manufacturable and will reduce the delay going from prototype to final product. These front-end considerations can also provide an end-of-life product support plan that accommodates unknown quantities and geographic distribution. Additive Manufacturing allows the aviation companies the option to digitise the complete supply chain from design, production data to the warehousing. This also allows the organisations to create a responsible supply chain with a lower impact on carbon emissions and almost zero obsolescence.
Additive Manufacturing processes and materials provide real benefits for the aerospace industry through manufacturing, performance and supply chain improvements. However, certification of AM aircraft parts is currently a very challenging endeavor for the for aerospace companies.
The primary reason is the lack of an established certification roadmap and qualified materials. Companies may be experienced with AM but are not aware of the critical aspects of this technology as it relates to aircraft certification. The result is a lack of specific guidelines and specifications needed to satisfy the certification communities. Then there are those familiar with the certification process but still see it through a traditional manufacturing lens, and lack the experience needed to translate the critical elements to the AM world. Also lacking is a database of AM material properties that engineers can use to design and develop aircraft parts using the AM process.
The absence of material property data means aircraft companies are left to develop this information on their own, a process that can be extremely expensive and time consuming. Consequently, companies that assume this challenge and develop their own data typically view it as proprietary information, which isn’t shared with the broader aerospace community. This creates an environment where all industry participants are forced to create their own data and processes, resulting in variability and a lack of material and process standards. As a basic requirement - materials, processes and machines must all meet industry certification and be created in an ISO 9001 facility, while the components themselves need to be produced in an AS9100 compliant facility.
First Polymer Specifications for Aerospace Industry
After a request from airlines through the International Air Transport Association (IATA)’s EMG to be able to realize additively manufactured plastic cabin parts, SAE International last year released the first Additive Manufacturing (AM) Polymer specifications for the aerospace industry. AMS7100: Fuse Filament Fabrication Process and AMS7101: Material for Fused Filament Fabrication represent the first specifications released under the AMS-AM Additive Manufacturing Non-Metallic (AMS-AM-P) committee.
These standards help define a consistent set of materials and process limits that both the user and producer agree to in support of part procurement activities. AMS-AM standards support the promotion of knowledge, standardization of practice and advancement of commerce in the emerging AM aerospace industry. The AMS7100 specification establishes the critical controls and requirements to produce reliable, repeatable, reproducible aerospace parts by Fused Deposition Modeling (FDM®) or other material extrusion production. This procedure creates guidelines that FDM System users will follow to approve new machines, processes and materials. Specifically, this new specification covers the configuration of the machine, operating software, machine calibration, machine and build parameters, and testing methodology required to create certified additively manufactured aerospace parts.
The AMS7101 specification establishes the certification requirements for materials to be used in FDM or other material extrusion additive manufacturing production for aerospace components. This specification outlines the technical information, production guidelines and documentation requirements for FDM material manufacturer.
Snapshot of Successful Business cases
Air France KLM
Frederic Becel, Design Manager and Innovation Leader, Air France says “DfAM and the thought process while designing the part is very important to ensure that Additive Manufacturing is efficient for us in Airline interiors”. The E & M division at Air France KLM began producing parts by Additive Manufacturing and testing them back in 2016. After an audit in November 2016, they were granted approval by EASA to use Additive Manufactured parts under part 21J process. Under this process Air France KLM have until now developed 20 parts and have certified 12 to be flight ready and fitted on airlines. In February 2017, The first AM part was certified and accepted as flying ready for the A321 Air France Fleet.
"Air France now has certified close to 700 flying parts for their own fleet and customer fleets".
Frederic Becel adds, “There is a cost saving by a factor of 2 – 4 including the costs for design for AM, certification efforts and production. Delay saving is noticeable but is not magic and the main goal is flight safety and how to improve it”.
In collaboration with Auckland University of Technology, Air New Zealand developed 3D-printed fold-down cocktail trays for its Business Premiere seat. This cocktail table may be a small beginning, but Air New Zealand has great hopes for 3D printed cabin components “A big advantage of 3D printing is that it enables us to make cost-effective lightweight parts ourselves, and do so quickly without compromising on safety, strength or durability,” says Bruce Parton, Air New Zealand’s chief operations officer. “Not only can’t we hold stock of every replacement part we might need, but we often only require a small number of units, which can be really expensive to produce using traditional manufacturing methods and can involve frustrating delays while a replacement part is delivered.” The airline is exploring other 3D-printed parts that could be used in its cabins.
Etihad Engineering, the MRO division of Etihad Aviation Group, collaborated with EOS and BigRep, to open the region’s first additive manufacturing facility with Design and Production Approval from the European Aviation Safety Agency in 2019. Etihad Engineering has a customer base spanning leading airlines and OEMs from South America to Europe, the Middle East and Asia. The facility was officially opened in a ceremony attended by His Excellency Ernst Peter Fischer, German Ambassador to the UAE in recognition of the relationship between the German companies EOS and BigRep and the UAE’s Etihad Engineering. Etihad Engineering first received EASA approval to 3D print with filament technology in 2017 and was on of the first airline MRO in the world to certify, print and fly 3D printed cabin parts. The latest approval, received in October 2019 covered powder bed fusion 3D printing technology.