ELLSWORTH AIR FORCE BASE, S.D. -- Members assigned to the 28th Maintenance Squadron’s Additive Manufacturing and Rapid Repair Facility conducted a cold spray repair to a B-1B Lancer Forward Equipment Bay (FEB) panel on April 8.
Though several panels have been sprayed to this point, this event marked a significant milestone in the application of this cutting edge technology.
“This is the first time that Air Force personnel have applied the cold spray technology using Air Force guidance and technical orders, with Air Force owned equipment, for a purely organic repair capability,” said Lt. Col. Daniel Wester, the 28th MXS commander.
He further elaborated that in the past, the equipment, process and guidance were developed in conjunction with industrial partnerships. This meant that conducting cold spray repairs at Ellsworth Air Force Base previously entailed a requirement to use commercially trained contractors as the spray technicians.
“There was a financial expense associated with this as well as increased process review and approval constraints,” Wester noted. “By transitioning to a purely organic capability we eliminate the excess financial expenses and mitigate additional layers of review resulting in reductions in aircraft downtime and an increase in aircraft availability.”
Cold Spray is much more reliable than the original method of repairing aircraft parts. It uses a machine that shoots metals at supersonic speeds onto an aircraft component. The metals mix and bond together, filling any missing or damaged areas and restoring the part.
“Cold spray technology allows us to repair previously unobtainable [or] non-repairable aircraft components like the FEB panel that is not repairable with conventional repair techniques,” said David Darling, the 28th MXS additive manufacturing facility site manager.
Using cold spray technology makes the previous form of part restoration obsolete. The original method had workers doing rivet repairs.
“We used to put a sheet of aluminum over the top of the part and proceeded to rivet it down, and then machine holes through both layers of the metal,” said Brian James, the 28th MXS additive manufacturing facility chief engineer.
This process for fixing parts is ineffective as drilling through the metal creates a stress concentration point – all the pressure and stress goes to each hole. This causes micro-cracks to form around it, which causes damage over time to the part. Additionally, using an older form of repair such as this had a much higher price tag.
According to Darling, the estimated return on investment was high for the recent cold spray repair. What would have normally cost $83,000 to replace instead only cost $4,000 to repair via cold spray by Ellsworth AFB’s team of technicians – saving the Air Force roughly $79,000 per panel.
This type of repair increases aircraft availability at a reduced operational cost through the sustainment of legacy aircraft components, Darling explained. Beyond saving money, the base’s cold spray capabilities improve mission readiness and capability as new technologies refine maintenance operations for the B-1 fleet.