(Image source: U.S. Air Force/R. Nial Bradshaw)

The F-22 Raptor gets its first metallic 3D-printed part

A new titanium component produced via powder bed fusion could save the U.S. Air Force time and money during F-22 maintenance.
Maintainers from the U.S. Air Force 574th Aircraft Maintenance Squadron (AMXS) have installed the first titanium additively manufactured titanium component on an operational Lockheed Martin F-22 Raptor. While the U.S. Air Force routinely uses additive manufacturing (AM), also known as 3D printing, to create parts for legacy aircraft, the service is beginning to incorporate the practice into supply chains for fifth-generation aircraft.

The component – a bracket from the kick panel assemble of the cockpit – was manufactured using powder bed fusion, a popular AM process commonly used in the aerospace industry. During the process, a digitally guided laser selectively melts a metal powder medium, fusing it to the previous layer. The process is more economical than traditional subtractive manufacturing methods like stamping, milling, or drilling, as unused “scrap” powder can be recycled for later use.

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The metallic printed bracket alongside the aluminum part it will replace on an F-22 Raptor during depot repair at Hill Air Force Base, Utah, Jan 16, 2019 (Image source: U.S. Air Force/R. Nial Bradshaw)

“One of the most difficult things to overcome in the F-22 community, because of the small fleet size, is the availability of additional parts to support the aircraft,” says Robert Lewin, 574th AMXS director.
AM technology enables maintainers to acquire replacement parts on short notice without minimum order quantities, which saves taxpayer dollars and reduces the time the aircraft is in maintenance.

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According to the maintainers, the finished AM part can arrive as fast as three days after ordering.

Furthermore, the original equipment manufacturer (OEM) bracket, a corrosion-prone aluminum component, is replaced 80 percent of the time during depot maintenance.

Although the new, printed titanium part is will not corrode, it will be monitored while in service and inspected during the aircraft’s next scheduled maintenance at Hill Air Force Base in Utah.

“We had to go to engineering, get the prints modified, we had to go through stress testing to make sure the part could withstand the loads it would be experiencing – which isn’t that much, that is why we chose a secondary part,” says Robert Blind, Lockheed Martin modifications manager.

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Solutions that are faster, cheaper, and better are not often come by: the service says that the new bracket will be printed for and installed on all F-22 aircraft during maintenance if this test case is validated.

Eight U.S. Air Force F-22 Raptors from Joint Base Elmendorf-Richardson, Alaska, sit on the flight line, July 9, 2018, at Yokota Air Base, Japan. (Image source: U.S. Air Force/Yasuo Osakabe)

At least five more F-22 metallic AM parts are planned for validation through public-private partnerships, in order to reduce costs and maintenance turnaround on one of the U.S. Air Force’s most advanced and expensive fighter aircraft.

“We’re looking to go a little bit further as this part proves itself out,” says Blind.

“Once we get to the more complicated parts, the result could be a 60- to 70-day reduction in flow time for aircraft to be here for maintenance,” says Lewin.

Information and interviews originally sourced by R. Nial Bradshaw, 75th Air Base Wing Public Affairs

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William Kucinski is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include literally anything that has to do with space, past and present military aircraft, and propulsion technology.

Contact him regarding any article or collaboration ideas by e-mail at william.kucinski@sae.org.
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