Mines Team Helps Pioneer Cutting-Edge On-Aircraft Repair of B-1 Fuselage Saving DOD $500,000

July 20, 2021
Mines Team Helps Pioneer Cutting-Edge On-Aircraft Repair of B-1 Fuselage Saving DOD $500,000
Staff Sgt. Chynna Patterson, a 28th Maintenance Group additive manufacturing spray technician, and David Darling, the 28th MXG additive manufacturing site manager, wait for the VRC Raptor Cold Spray machine to heat up at Ellsworth Air Force Base, S.D., May 12, 2021. The cold spray machine was developed by VRC Metal Systems to be cost effective and capable of restoring aging aircraft components. (U.S. Air Force photo by Airman 1st Class Quentin K. Marx)

A team of students and professors from South Dakota Mines assisted Air Force personnel in employing cold spray technology to repair a broken hinge tied to the fuselage of a B-1B Lancer. Cold spray, an additive manufacturing method, is essentially spray on metal that can be machined to fit. The technology uses metal microparticles that are sprayed at very high velocities. These tiny particles then adhere to the original metal on impact, forming a dense coating or deposition. In many cases, cold spray can be used to restore worn and damaged aircraft parts to extend service lifetimes. 

Without cold spray technology, the fix of this B-1 would have required a lengthy repair process and a cost estimated to exceed a half of a million dollars which would have included dismantling part of the aircraft and sourcing spare parts from a salvaged bomber.

“This would have normally involved eight weeks of downtime. With cold spray we were able to do this in a couple of hours,” said Brian James, a Ph.D. graduate student at Mines, and a chief engineer with the 28th Maintenance Group at Ellsworth Air Force Base. James is part of a team inside the 15,000 square foot Additive Manufacturing Facility at Ellsworth. He added this technology is a game changer for aircraft maintenance.

James says the innovative repair of this B-1 is 14 years in the making. It started in the mid-2000's with research into cold spray technology at Mines that sought to find better ways to restore obsolete and legacy aircraft components. As the research and development progressed over the years, it led to spin-off companies and the addition of the additive manufacturing technology to the toolbox of the 28th Maintenance Group.  “This facility at Ellsworth is the first of its type,” said James. “What we are doing here is taking technology that's been tested and proven in the lab and infusing it right at the combat level.”

James noted there is a long list of individuals, organization and industry partners, political leaders who have helped make the program successful, including Dr. Heather Wilson, former Secretary of the Air Force and Mines president, industry partners like VRC Metal Systems, Army and Air Force Research Laboratories, and numerous Mines students and professors who have contributed hard work and expertise over the years.

“The school has been a huge supporter, especially Dr. Grant Crawford who helps us come up with solutions to problems we have encountered on the way,” James said.  “More recently the addition of the X-Force Fellowship program though the National Security Innovation Network is bringing young innovators to the table,” James added.

Zac Hogan, a mechanical engineering major and an X-Force fellow from Mines, is the latest edition to Ellsworth's additive manufacturing team. “It's wonderful to work on real-world problems and there is a creative freedom in the approach here,” Hogan said. “What they are interested in is problem solving and how we go about it is up to us. We attack the problem from every perspective, and we work to make sure we are utilizing all the resources available in finding solutions.”

Hogan is working with X-Force fellows from universities around the country on the project. “Zac has been a huge benefit to the program, he has brought a fantastic work ethic and fantastic problem solving to the team,” said James.

The work of this team is showing that the employment of cold spray technology improves combat readiness of legacy systems like the B-1. David Darling who spent 26 years in the Air Force maintenance is the site lead at the Ellsworth Additive Manufacturing Facility. He says the array of testing equipment at Ellsworth's Additive Manufacturing Facility can be used to demonstrate the strength of any repair. “We have a full lab including a scanning electron microscope, hardness testers, tinsel testing, and other equipment,” Darling said. “So, within hours after application we can see test results that show our success."

For the Air Force, cold spray increases the lifespan of a weapons system, and for maintenance personnel on the ground, the technology offers a new highly cost-effective tool that revolutionizes repair of critical aircraft components. Staff Sgt. Chynna Patterson, a machinist and welder assigned to the 28th Maintenance Squadron at Ellsworth, spent 10 years working on other aircraft like the A-10 Warthog. “This technology allows us to maintain the aircraft in ways that would previously have been very time consuming and very expensive,” she said. Patterson said she believes additive manufacturing and cold spray can be used on other aircraft systems Air Force wide. “Learning all the applications of this technology has been wonderful,” she added.