Jetrader - Summer 2017 - 15

part for flight in 2002. The manufacturer
currently has "several hundred types and
tens of thousands of 3D-printed parts flying
on both commercial and defense programs."
Many in this space are implementing similar programs with equal success, including
Rolls-Royce, Pratt & Whitney, Honeywell
and countless others.
In February 2015, GE was the first to
receive FAA certification to use a part created via AM in a commercial jet engine,
with the part - a T25 engine sensor -
being retrofitted to more than 400 Boeing
777 GE90-94B engines. The manufacturer
has since been cleared to implement additional parts in its engines.
Airbus made a big splash at the 2016
Berlin Air Show when it unveiled an entire
aircraft made up of 90 percent 3D-printed
parts. Although essentially a large-scale
model, it provides further proof that manufacturers are looking at this technology as
a cornerstone of their approach moving forward. In this vein, Airbus expects to "print"
roughly 30 tons of metal parts a month by
2018 and has expanded AM efforts into its
satellite and UAV areas of service, as well -
receiving, for example, certification to use
a titanium alloy bracket aboard its Atlantic
Bird 7 telecommunications satellite.
More recently, Siemens announced a
breakthrough in February 2017 by printing gas turbine blades that were successfully put through full-load engine testing.
There's admittedly still a vast distance to
cover before the parts are certified for
commercial flight, but it's a huge step in
the process' continued evolution.
According to Dr. Leo Christodoulou, director, structures and materials, enterprise
operations and technology for Boeing, nearly
all the manufacturers in aviation are exploring, if not implementing, an AM strategy.
"The attractiveness is that you can create designs that you simply couldn't create
by machining a block of metal or through
forging or even with the injection molding
of polymers," Christodoulou said. "In AM,
complexity is free, and that's hugely attractive to the manufacturers. For example, if I
were to machine a very complex path vs. a
straight line, there would be a huge difference in cost. The ability to produce things
of complex nature [via AM] easily enables us
then to design for that complexity. This, in
turn, opens up new realms of possibilities."

Simultaneously, as the technology has
evolved, so, too, has the availability of
suppliers. Key players in the supply base
are emerging at a rapid pace, which drives
costs down through competition and
increased availability.
"We are definitely at a turning point,"
Christodoulou said. "In the early 2000s,
capacity was limited to essentially one
supplier. Today, our supply base is 30, 40,
50 times greater, and it's growing exponentially. The diversification in that base
prevents downtime and delays, which can
add considerable cost to a project."

New Frontiers
Setting aside the novelty factor associated with this rapidly evolving technology, there are numerous measurable and
significant benefits to be had, including
stronger and potentially longer lasting
construction, improved manufacturing
efficiency and reduced weight of the
final part. And while decreased manufacturing costs and a longer lifecycle for
the part are certainly enormous positive
attributes, the possibility of increasing
fuel efficiency through decreased weight
is one of the most tantalizing aspects for
aviation application.
"A conventionally made part is CNC (computer numerical control) machined," Wohlers
said, "so you end up with about 80 percent
or even more - even 90 percent - in scrap
in the form of chips on the floor. With AM
you do have some scrap, but it's usually
closer to 10 percent, not 80 or 90 percent.
In addition to the savings with respect to
waste, it generally takes much less in the
way of materials to produce the part. Less
materials used to create the part equals
lighter weight, which means less fuel.
That, in and of itself, is enough of a reason for aerospace manufacturers to explore
this technology."
It's important to note, however, that the
potential for fuel savings is great, but the
current percentages of AM-created parts
on any given airplane are still incredibly
small. For example, of the millions of parts
on a commercial airliner, Airbus estimates
that roughly 2,700 parts of its A350-XWB
were created through AM. And all of those
parts fly in areas of the plane considered
"non-critical" - meaning that part failure
wouldn't cause a catastrophic event.

GE's T25 engine sensor, which was the
first commercial jet engine part created
via additive manufacturing to receive FAA
certification for flight. IMAGE: GE AVIATION

The capability to create parts to serve
flight-critical functions does exist, but a
big challenge in increased adoption is that
current FAA regulations are written to the
specifications of traditional manufacturing methods. However, the FAA is working
diligently to better understand the technology and provide certification avenues for
AM-created parts.
In 2016, at the National Institute of
Aerospace's On-Demand Air Mobility conference, FAA representatives Jim Kabbara
and Michael Gorelik hosted a session titled
"Additive Manufacturing: FAA Perspectives"
in which the administration stressed that
while there are challenges unique to AM,
the technology is clearly undergoing
"rapid expansion," and the FAA's regulatory framework will need to evolve to serve
as a key enabler of continued development
and implementation.
To that end, Wohlers cited constant FAA
presence at AM-related conferences as proof
of the administration's commitment to fully
understanding the technology as it continuously monitors the process' evolution.
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Jetrader - Summer 2017

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