Making Additive Standard

A fitting for a V-22 nacelle link mid-build inside a directed energy deposition 3-D printer at Penn State University’s Applied Research Laboratory, which has partnered with Naval Air Systems Command in developing its additive manufacturing protocols. (Photo courtesy of NAVAIR Prototype and Manufacturing Division and Penn State ARL)

NAVAIR Prepares to Make 3-D Printing a Regular Part of Business

Liz McMichael wants to put herself out of business.

Less than two years after her team first demonstrated the viability of a 3-D printed aircraft part, McMichael, the additive manufacturing (AM) and digital thread (DT) integrated product team (IPT) lead for Naval Air Systems Command (NAVAIR), is ready to begin an enterprise-wide integration of the technology.

Additive manufacturing is the process of building an object in layers using 3-D printers that extrude materials such as plastic polymers or powdered metals. Traditional or “subtractive” manufacturing typically involves cutting or machining bulk materials into an object.

Using digital models, 3-D printers can create in hours what would normally take days or weeks to make using traditional methods. The technology also allows for innovative designs that are either not possible or impractical via subtractive manufacturing.

McMichael’s team has served as a one-stop shop for 3-D printing requests from NAVAIR program offices and the fleet alike since July 2016, when it flew its first safety-critical AM parts—a titanium engine nacelle link and fitting assembly for the MV-22B Osprey. It was the first time a naval aircraft had flown with a flight-critical part made using additive manufacturing.

A finished, 3-D printed fitting for a V-22 nacelle link. (Photo courtesy of NAVAIR Prototype and Manufacturing Division and Penn State ARL)

 

But managing a large portfolio of AM components will be difficult for her relatively small crew, so the team is working to begin scaling additive manufacturing into the NAVAIR enterprise. In other words, taking AM from a novel, promising technology, and making it a standard process directly available to program offices, operational users and industry partners.

“We want to make AM usable across NAVAIR, and ensure we have the tools and processes in place to make AM available and safe to use across Naval Aviation,” McMichael said. “That means that everyone who wants to use AM can use the tools and process we’ve put in place, and teach their people how to use AM safely and effectively. We want to have NAVAIR do additive manufacturing as an organization, not with just a small, dedicated team.”

Scaling a disruptive technology like additive manufacturing into NAVAIR has been a multistep process for the AM/DT IPT. First came proving that the technology could be safely used for aviation, which the team accomplished with the July 2016 flight test.

Next was the effort to “scale up,” or demonstrate that AM technology could apply beyond an initial prototype. As of February, the IPT had a portfolio of more than 80 projects, and it hopes to have more than 1,000 parts approved within the next two years.

If a 12-fold expansion sounds like a tall task, McMichael points out that the team’s scope has already grown very quickly since July 2016.

“We have to keep it moving forward. Each time we approve an AM component, we are learning how to improve the process and go faster,” she said. “One of the most difficult things for a disruptive technology like this is expanding from doing it once to doing it a million times.”

Each of those projects represents a success for their respective program offices, both in terms of cost and turnaround time.

One of those greatest successes came last spring in the form of a flip-top valve for the T-45 Goshawk that allowed training pilots to breathe cabin air up to a certain altitude. At a time when the T-45 fleet had been grounded due to concerns over physiological episodes, the valve allowed trainees to resume flying while fixes to the onboard oxygen generation system were put in place, ensuring that the training schedule for pilots could be maintained (see sidebar below).

The IPT was brought in on May 22. Following ground and flight testing, it finalized a production plan for the valves May 27. The team then reached out across NAVAIR and Naval Sea Systems Command sites for available 3-D printers. Ultimately, six different sites helped print the valves, and an initial batch of 300 was shipped June 6. Another 500 were shipped by the end of July. It was the first time distributed AM production had been used to meet such a short timeline.

A 3-D printed flip-top valve as applied to a T-45 Goshawk breathing mask. The valve was created to allow T-45 students to continue syllabus flights while fixes were made to the aircraft’s Onboard Oxygen Generation System. (U.S. Navy photo by Emanuel Cavallaro)

“That’s basically from start to finish, 300 out the door in around two weeks,” said Brennen Cheung, a member of the IPT’s Logistics Innovation Cell, which coordinated production of the valves. “We learned how we could use distributed printing and get good quality to meet an almost impossible timeline.”

The parts could have been delivered even quicker had business practices been streamlined to allow it.

“What held us up wasn’t the fact that we had any technical issues with the printers; it was that we couldn’t get funding to people fast enough. It showed us that business processes need to mature at the same time as AM technology does,” McMichael said.

Another notable success was a small, plastic clip that attaches to the visor of an H-1 pilot’s helmet. The clips often snap when pilots bump into something, costing more than $200 each to replace. The Logistics Innovation Cell developed an AM technical data package, or TDP, to ensure that a 3-D printed version would meet airworthiness requirements. Each clip now costs 75 cents to print.

“Each project has taught us more about how AM can address readiness and where the most value is. Scaling up from the first demo let us put a plan in place to get the right people and team to help mature AM processes so everyone can use them,” said Dan Krivitsky, the AIRWorks AM/DT lead. A Naval Air Warfare Center Aircraft Division organization focused on innovation, affordable solutions and rapid response, AIRWorks is part of the IPT, focused on integrating AM across Naval Aviation.

The same innovation cell that produced the H-1 clip has also designed a TDP that will allow the winch pendant housing for the MH-53E Super Stallion to be printed on demand. The housing protects the winch controller, and normally takes over a year to deliver to the fleet.

“This is another example of where AM can help with readiness,” said Jaleesa Needham, a materials engineer working with the H-53 program office to develop standards for the housing. “As 3-D printers start to become available to logistics and operational people, they’ll be able to use our 3-D TDP to print parts when they need them. We have to make sure that they understand how to use the TDP, and they have the right materials and printers available.”

The third step of scaling additive manufacturing across NAVAIR is scaling out, McMichael said. “Scaling out is about integrating the people you’ve trained and the tools and processes that you’ve developed into how NAVAIR does business,” she said.

“AM right now is squarely between scaling up and scaling out,” Krivitsky said. “AIRWorks is the key to scaling out as it serves as a bridge from the initial development of AM to full enterprise integration. It’s a cross-functional team that’s agile, so we can staff quickly, bring people in and train them, and then they can go and train other people across the organization.”

If the July 2016 flight test provided an initial demarcation point for NAVAIR’s additive manufacturing initiative, another came in February with the team’s release of two official AM standard work packages—one for low-risk, polymer aviation parts, and another for development of 3-D TDPs. These standards provide guidance for
NAVAIR engineers on how to print AM parts so that they can be used safely and ensure that they can meet airworthiness requirements. They also let anyone who wants to use AM for Naval Aviation—be they a Sailor or Marine in the fleet, an engineer in a program office or an industry partner—understand how to work with NAVAIR to get AM parts approved and made.

“Anybody can print something,” McMichael said. (She’s right. See the sidebar on page 36 for proof.) “They need to be able to print it in a way that meets required performance. We’re trying to ensure that people know that making aviation components requires some controls to ensure safety. The guidance provides the details of what controls are needed based on what a part does. If you want to make AM parts for naval aircraft, here are the people who can tell you how to do that.”

Krivitsky noted that industry has been anticipating NAVAIR’s release of additive manufacturing standards. Commercial vendors have been 3-D printing for years, but without standards, they haven’t known how to ensure that components would meet airworthiness requirements.

“The standards define the data that NAVAIR needs and how we are planning on qualifying vendors so that we can leverage industry to make AM parts,” he said.

Eventually the standards developed by the team will help facilitate operational manufacturing. The IPT is working with Marine Aviation Logistics Squadrons to help define the tools and processes they will need to make AM components safely.

McMichael expects a standard work package for metal parts and vendor qualification to be released in the coming months.

But for the time being, the AM team will continue taking requests. To that end, the team will be launching a website where program offices or fleet Sailors and Marines can fill out a form and directly request parts that they’d like to make using AM. Those requests will be coordinated with program offices to prioritize and ensure that airworthiness requirements are met. The website will allow users to track the progress of their requests, access 3-D TDPs for approved parts, and ensure that users understand what level of approvals are needed to print parts. Until the web site is formally launched later this year, the team is taking requests via email at navair_am.fct@navy.mil.

“We’re getting a lot of requests now,” McMichael said. “The Naval Aviation community sees the potential for AM and wants to use it to solve problems. The reason we’re standing up a website is to centralize the requests so we understand the demand, and have a way to prioritize and manage them.”

The website and the AM standards for polymer and metal are the first major steps to scaling out additive manufacturing across NAVAIR, McMichael said. She’ll know it’s working if her cell phone stops ringing as often.

“Right now, if someone wants a 3-D printed part for Naval Aviation, they know how to contact the AM team directly,” she said. “But that approach doesn’t scale very well. With the website and NAVAIR AM email approach, we’ll have a much better understanding of the demand for AM, and be able to respond to it.”

Written by Jeff Newman, a staff writer for Naval Aviation News.


T-45 Solution Made possible by 3-D Printing

A 3-D printed flip-top valve as applied to a T-45 Goshawk breathing mask. (U.S. Navy photo by Emanuel Cavallaro)

Following the April 2017 grounding of the T-45C Goshawk fleet due to concerns over physiological episodes, additive manufacturing played a key role in a temporary fix that got student pilots back in the air.

The operational pause began after T-45C instructor pilots reported they and their students had been experiencing an increasing rate of hypoxia—or oxygen deficiency—due to contamination of the aircraft’s Onboard Oxygen Generation System (OBOGS). The pause was lifted after 12 days for instructor pilots, but students remained grounded until July, when a solution bypassing the OBOGS altogether allowed them to fly up to 10,000 feet, enough to cover roughly 75 percent of their syllabus flights.

Conceived by Rich Coughlan, a helmet team engineer with the Human Systems Department at Naval Air Systems Command (NAVAIR), the fix came in the form of a modified MBU-23 helmet mask that allowed student pilots to breathe ambient cabin air through its exhalation valve while keeping the inhalation port connected to an emergency oxygen supply. This gave students the ability to fly up 10,000 feet with confidence that, should they begin feeling hypoxic, backup oxygen was still available.

The modifications involved opening the exhalation valve to allow in cabin air, and replacing the inhalation valve with the combination valve from the older model MBU-12 mask, through which aircrew both inhale and exhale.

But a new exhalation port valve was needed so that student pilots could quickly and easily close off the cabin air if and when they needed to engage the emergency oxygen.

The design went through multiple iterations—“The first came out looking like a NASCAR gas cap,” said Alston Rush, another engineer with the helmet team—but once it was finalized, NAVAIR’s additive manufacturing team was called in to help get the new valves out to the fleet.

Brought onboard May 22, the team put a prototype through ground and flight testing before utilizing eight 3-D printers at six different sites to print and ship 300 valves by June 5, exactly two months after the operational pause began.

“This is an insanely short timeline. That’s basically from start to finish for 300 out the door in 15 days,” said Liz McMichael, NAVAIR’s additive manufacturing and digital thread integrated product team lead. “That was really eye watering.”

All told, the initial batch of valves was installed on T-45Cs by June 9. A second batch of 500 valves were shipped out between June 16 and July 20, with student flights resuming in late July.

“3-D printing is great for rapid prototype and design, and making things really quickly,” Rush said. “If you wanted to make this injection molded, it would probably take you a few weeks to a couple months to actually get your mold created and start making them. Once you make the injection mold, you can cut them out really quickly, but it’s that time difference between a few months and a couple weeks.”

The solution ended up having a short lifespan—by September, other fixes to the T-45C had students back flying on OBOGS again— so the valves would have likely never made it to the fleet had they been traditionally manufactured.

“We would have lost our timeline,” Rush said.

“Just the contract action to go back to the manufacturer would have taken too long,” Coughlan said. “We would have never even been able to send them money, so we would have never been able to get any of this done in time.”

And even though the valves were only used for about six weeks, getting back that month-plus of training flights proved crucial to keeping the student pilots on schedule.

3-D printed exhalation port valve. (U.S. Navy photo by Emanuel Cavallaro)

“In the bigger picture, it’s larger than just losing a few months of training time; it shifts the entire schedule that the pilots have,” Rush said. “The beauty of this project was that it bought time, because we were getting so backlogged while we were making fixes to the jet, if it had reached a certain point, the pilots would have had to re-qualify. And after that, they would have had to completely restart their training, and three months would turn into a year, because they’d have to shift to the next class. And even bigger than that, the F/A-18 pilots that were in the fleet would have had to extend their tours of duty, so they couldn’t move
up to higher positions, so it would have
had long-term consequences on their
careers as well.”

Jeff Newman is a staff writer for Naval Aviation News.