Additive Manufacturing Promises to Boost Naval Aviation Readiness
by Jeff Newman
At a time when the U.S. Navy and Marine Corps are stretching aircraft beyond their intended service lives to meet training and operational needs, a revolutionary technology that could forever change the way the nation’s military maintains its platforms signaled its hastening maturity July 29 with a first-of-its-kind flight demonstration.
A team of engineers assembled nearby gave a hearty cheer when the MV-22B Osprey successfully lifted off and hovered above its airstrip at Patuxent River Naval Air Station, Maryland, before tilting its rotors forward and zooming off—a culmination of 18 months of work to safely outfit and fly an aircraft for the first time with a flight-critical part made using additive manufacturing techniques.
Equipped with a titanium, 3-D printed link and fitting assembly in one of its engine nacelles, the Osprey completed its standard flight performance envelope before landing safely less than an hour after taking off.
“The flight went great. I never would have known that we had anything different onboard,” said MV-22 project officer Maj. Travis Stephenson, who piloted the flight.
A technology that has existed since the early 1980s but undergone rapid development in recent years, additive manufacturing refers to the process of using 3-D printers to build objects in layers using one or more materials—such as plastic polymers or metallic powders—as opposed to traditional “subtractive” manufacturing, where bulk materials are cut or machined down into the desired object.
Using digital model-based data, 3-D printers are able to create in minutes and hours objects that, using traditional methods, would normally take days or weeks. The potential for cost- and time-savings as well as innovation are immense regardless of industry, and the military is no exception.
Which is why Naval Air Systems Command (NAVAIR) developed an additive manufacturing roadmap in September 2014, with one of its goals to fly a flight-critical part—meaning one deemed essential to maintaining safe flight—within three years.
“We did it in 18 months,” said Liz McMichael, NAVAIR’s additive manufacturing and digital thread integrated product team lead. “That’s not something from my experience that happens very often.”
McMichael called the test “a validation that happened faster than we honestly thought [was possible] going into it.”
“We were able to go in and make four different production designs of this additive manufacturing part in a very few months,” McMichael said. “That’s the equivalent of multiple production line stand-ups, and if we did that in a traditional way, it would have taken years, so just being able to change how we do things has really shown us that this technology is going to be usable. We think we are starting to understand the processes that we need to do to use it safely.”
“NAVAIR and the Navy have been at the pointy edge of the spear. We recognize the potential of additive manufacturing to address operational availability, enhance performance and reduce cost, and so our role has been to be the technical and programmatic lead for the Department of Defense,” said Bill Frasier, NAVAIR’s chief scientist for air vehicle engineering and the Navy’s senior scientist for materials engineering. “Not bragging or anything, but we have been recognized as taking the lead on that. We are breaking new ground and it is going to have a very positive effect on us in the future.”
Proving It Safe
In deciding which parts to begin printing, McMichael said her team settled on the V-22 link and fitting, one of four that secures each nacelle to its wing, for a couple reasons—the part is titanium, one of the more mature manufacturing materials, and installed in a failsafe configuration where if the 3-D printed link broke, the other three would keep the engine fastened to the wing.
After selecting the part, McMichael’s team approached the MV-22B test program about using the Osprey as the first platform to demonstrate the viability of using additive manufacturing to produce flight-critical aircraft parts.
“We took a look at that, what their proposal was and felt like it was absolutely something we could support,” said Ray Dagenhart, lead test engineer for the MV-22B test program. “It’s not a new part. It is obviously a legacy part that we have instrumented and flown for years and very much know the history of. The additive manufacturing team took a look at that and chose this part for that reason, as well as it being a redundant link.”
As difficult as it was to produce the part, McMichael said her team found it just as challenging “culturally” to convince test engineers that a 3-D printed part could be just as strong and dependable as its traditionally manufactured version. But after the part was printed at Naval Air Warfare Center Aircraft Division (NAWCAD) in Lakehurst, New Jersey, it proved in component testing to be just as sturdy, and in some areas more so, than the original link and fitting.
“One of the big points of this demonstration was to establish that this can be done, to showcase that printing a flight-critical part is possible,” said Eric Kline, NAVAIR’s prototype manufacturing lead for additive manufacturing. “What that does is it sends a strong message to the whole organization that if we can print a flight-critical structural part, then we can do those less-critical items knowing that this process is sound.”
McMichael said her team will continue working with the V-22 program to incorporate the 3-D printed link and fitting as a formal configuration change for the aircraft.
In addition to the link and fitting, McMichael’s team has identified five other flight-critical parts it hopes to print and fly in the coming year, all for Marine rotorcraft—a stainless steel lever for the V-22’s fire extinguishing system, titanium Clevis and lug latches for the CH-53K King Stallion heavy-lift helicopter, and stainless steel uniball suppressor support and engine mount fitting for H-1 helicopters.
Cutting the Logistics Chain
The Navy has used 3-D printers to rapidly make prototypes since the early 1990s, and in recent years has been printing non-safety critical parts and tools with increasing frequency. In June 2014, technicians at NAVAIR’s Fleet Readiness Center (FRC) East, located at Marine Corps Air Station Cherry Point, North Carolina, used 3-D printed tools to make and deliver replacement parts seven days after an AV-8B Harrier damaged its nose cone following a hard landing on USS Bataan (LHD 5). Last year, maintainers at FRC Southeast in Jacksonville, Florida, saved invaluable time repairing a P-8 Poseidon’s wheel-well truss when they 3-D printed a prototype of a repair fitting and discovered flaws ahead of its delivery by Lockheed Martin.
But following the July 29 demonstration, Navy officials foresee a future where fleet maintainers as well as industry partners can print any part, safety-critical or not, on demand.
“Initially our real goal is to make sure we understand the manufacturing processes and we can ensure that when we put an additive manufacturing part on our aircrafts, particularly metal parts, that we know how it is going to perform,” NAVAIR Commander Vice Adm. Paul Grosklags said. “We need to have quality control processes and standards that we can implement for ourselves and our industry partners if they are manufacturing it. Much like any other part that we put on an aircraft, we must understand how it will perform.”
Ultimately, the goal is to have ships deploy with 3-D printers onboard, ready to print parts as needed from stores of composite materials, cutting down on the need to keep large reserves of commonly-needed parts, and removing from the logistics chain the timely process of flying parts manufactured on traditional land-based production lines out to sea.
The amphibious assault ship USS Essex became the first Navy vessel to have a 3-D printer installed onboard in 2014, and its Sailors have used the machine to print a variety of basic items, such as oil reservoir caps, deck drain covers and medical supplies.
USS Harry S. Truman (CVN 75) and amphibious assault ship USS Kearsarge (LHD 3) deployed with 3-D printers last year, and the Truman made news this summer when the digital design file for the TruClip, a replacement radio clip produced by its Sailors, was sent to the International Space Station for its astronauts to use in their 3-D printer. Designed because the original radio clips were breaking frequently, each TruClip costs about 6 cents to produce, a roughly 10,000-percent savings on the $615 it previously cost to replace each clip.
Apply this to the world of aircraft maintenance, and replacement parts that typically take months or even years to procure could theoretically be printed overnight and readied for installation in a matter of days.
“One of the opportunities that additive manufacturing has is just the rapid ability to make parts compared to other processes,” said Greg Welsh, a NAVAIR materials engineer. “We have a lot of assets that are nearing the end of their life and obsolescence can be a problem. We have a lot of issues where we have a long lead time for parts or a diminishing supply base where it is hard to get parts. So additive manufacturing offers a way to, rather than waiting for sometimes over a year to get a part or qualifying a new vendor, to be able to print things much more quickly.”
Using 3-D printers to make parts also removes the need for custom-designed repair tools, which can often take just as long if not longer to design and manufacture as the actual repair work takes to complete.
“We are really interested in additive manufacturing because you can produce parts that you need quickly and there is no tooling required for it,” said Brandi Briggs, a mechanical engineer with the Nondestructive Inspection Branch of NAWCAD. “You use the same machine to produce lots of different parts, almost anything you can think of, and that makes it really different from traditional processes and allows us to reduce the time that our aircraft are down.”
Printing the Future
Additive manufacturing also carries the promise of allowing engineers to come up with “novel design concepts” that they previously could not entertain, said John Schmelzle, additive manufacturing model-based definition lead at Lakehurst.
“In a traditional design, an engineer always has to think about how you’re going to make it,” he said. “We have to design for manufacturer ability, which is kind of a constraint on the design engineer. You’d love to be able to just make anything, but you can’t. Additive manufacturing, it unleashes a lot of those constraints.
“I always like to say that in additive manufacturing, the real constraint becomes the limit of the engineer’s imagination, as opposed to the constraints you have in traditional manufacturing, and to somebody who’s very creative, that thought is kind of provocative, that you can do almost anything with it.”
Speaking of imagination, Schmelzle didn’t bother reeling his in while considering the potential additive manufacturing holds for the future.
“You look at the USS Enterprise and Jean Luc Picard,” he began, referencing the famed “Star Trek” starship and space captain, “he goes up to his replicator and they ask for a part, and out comes the part, and I see that as a potential—maybe not tomorrow, maybe not in a few years—but maybe long term where we could just print out the parts instead of ordering them. Get rid of the entire logistics chain, and send electrons as opposed to sending parts.”
Regardless of whether 3-D printers are ever able to match Starfleet’s replicators, additive manufacturing promises to transform the Navy’s ability to sustain and repair its aircraft, as well as design and field new platforms, weapons and sensors.
“If you look at our readiness posture and you look at what we need to do to accelerate, we need to improve not only how we get our airplanes back from the fleet and how we sustain them right now, but we need new capabilities out there faster, and additive manufacturing is a technology that enables that,” McMichael said.
Being part of the first group to successfully demonstrate the viability of 3-D printed safety-critical parts has McMichael’s team geared up to do more.
“To be able to open up new opportunities, it’s really exciting getting involved in something like this right at the beginning, right at the forefront and being a part of the team that will help make decisions and shape where this technology will go and how it will be implemented in the Navy,” Briggs said.
Jeff Newman is a staff writer and contributing editor to the Naval Aviation News magazine.