The 3D-printed insert allows to address a design issue of the machinery used to handle 20 mm munitions for the M61 Vulcan Gatling gun, demonstrating the increasing use of additive manufacturing in the military.
Senior Airman Devon Word, a conventional munitions crew chief from the U.S. Air Force’s 48th Munitions Squadron, solved a perennial ammunition handling issue faced by the 48th Fighter Wing at RAF Lakenheath, U.K., which often saw 20 mm rounds jamming while moving from the replenisher table to the ammunition loader. The frequent jamming makes manual intervention necessary, with “15 minutes of troubleshooting per jam” required which “may also cause injury to the operator.”
In fiscal year 2023, according to the press release, there were 319 operations resulting in an average of 957 instances of jams using the replenisher table. These accounted for approximately 798 man-hours due to the need for at least four personnel during operations.
Word developed a specially designed 3D-printed insert that addressed the old design issue causing the stoppages – a gap between the rounds and the top of the replenisher table. The unit-level innovation could save the 48th FW and U.S. Air Force over 750 man-hours annually, the unit said.
F-15 muharebe uçağına 20 mm mühimmat yükleme anı.#F15 pic.twitter.com/koB6mEAYZv
— Askeri Çalışmalar Merkezi (@ASCAM__) September 30, 2024
The replenisher table and the loader mentioned are the two subsystems which make the Universal Ammunition Loading System (UALS), used to load 20 mm rounds for the M61A1/M61A2 20mm Gatling gun which is standard across nearly all American aerial combat platforms. In the Air Force’s case, the UALS is used to load the munitions on the F-15C/D Eagle, F-15E Strike Eagle, F-15EX Eagle II, F-16 Fighting Falcon and F-22 Raptor. More specifically, the replenisher table is used to inspect and transfer munitions from storage to the loader, which is then used to physically transfer the munitions inside the aircraft.
The innovation effort has been praised by senior officers as an example of grassroots personnel-led innovation to address routine techno-logistical issues. “Airmen working directly with equipment and processes often have unique insights into operational challenges and potential improvements,” said Lt. Col. Jonathan Tolman, 48th MUNS commander. “The military’s willingness to embrace and implement ideas from frontline Airmen like Staff Sergeant select Word’s invention, demonstrate adaptability, which is crucial in rapidly changing operational environments.”
The insert’s innovation
The press release from Lakenheath said that Word, a 48th Munitions Squadron conventional crew chief, identified the persistent problem with 20 mm ammunition replenisher tables frequently jamming and requiring constant troubleshooting and repairs. This was owing to a design flaw where the current gap between the rounds and the top of the replenisher table allows multiple rounds to fall onto the loader rather than a single round, leading to 15 minutes of troubleshooting per jam.
The manual intervention necessary to resolve ammunition jamming may cause injury to the operator, so Word’s ingenuity addresses a recurring issue with a critical piece of equipment, significantly improving the safety and efficiency of operations, said the unit.
“It was frustrating to see the team losing time and resources to repeatedly fix the same problem. I knew there had to be a better way,” said Word. The press release said Word collaborated with Staff Sgt. Bethany Levi, Air Force Repair Enhancement Program non-commissioned officer in charge for the 48th Maintenance Group, to conceptualize and design a simple yet highly effective insert for the machine.
Col. Tolman also noted how this invention conserves resources while enabling the operator to work uninterrupted. The insert designed by Word prevents ammunition jams during the loading phase and reduces overall operation timelines by compensating for the table’s design flaw.
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Staff Sgt. Levi, along with Senior Airman Joshuah Fontena, a 48th Equipment Maintenance Squadron aircraft metals technology journeyman, 3D-printed 11 prototypes of the insert and completed six trials on the load table. Released photos showed Staff Sgt. Bethany Levy using graphic modeling on a computer to design the ammunition guide, and a Stratasys F900 3D printer to manufacture the insert.
Benefits
After months of testing and adjustments, SrA Word’s insert is in regular use within the 48th MUNS and has proven to drastically reduce machine malfunctions, said the Air Force, resulting in a significant reduction in time spent reloading 20 mm ammunition.
Word credits the project’s success to teamwork and resourcefulness. “I couldn’t have done it without the support of my fellow Airmen and leadership,” he said. “This is the product of our shared commitment to improving the way we work.”
The reclaimed hours, thanks to Word’s innovation, will allow 48th MUNS Airmen to focus on other critical mission tasks. The impact of this invention, however, is yet to be realized according to the Air Force. In fact, the team working on this innovation is currently in the process of patenting the design and sharing it with other munitions squadrons across the service to solve this well known frontline operator issue and significantly increase operational readiness and efficiency for all munitions Airmen.
The military’s organic innovation and 3D-printing
The innovation also bears a more widespread use of additive manufacturing, when defense majors are adopting the practice to design larger capital weapons systems like hypersonic cruise missiles and drones. Combined with digital engineering and modular, open systems architecture, which have gone into platforms like the B-21 Raider, the idea is to rapidly prototype and scale cheap, upgradable weapons in a large conventional war.
This also envisages building metal spare parts, precision components and sub-assemblies of capital systems for quick repairs and shorter downtimes. In March 2023, Travis Air Force Base, California, revealed how maintainers from the 60th Maintenance Squadron and 349th Aircraft Maintenance Squadron, along with engineering and engineering support contractors from the C-5 System Program Office out of Robins AFB, Georgia, modified an internal part for a C-5M Super Galaxy by incorporating 3D-printed materials.
This was done to replace a “hump-shaped aerodynamic fairing panel” that was missing, for which the C-5 SPO suggested integrating 3D-printed parts made from Antero 800NA, a new thermoplastic material. Integrating 3D printing technology resulted in faster turnaround times and reduced costs.
The use of additive manufacturing also helps to provide the option for the 60 MXS to produce some parts on demand, rather than the lengthy sourcing process from third parties if a part is unavailable locally. Traditionally, spare parts for the C-5M have been expensive and time-consuming to produce, as they required specialized tooling and long lead times.
The U.S. Army has the Jointless Hull 3D metal printer at RIA-JMTC (Rock Island Arsenal-Joint Manufacturing and Technology Center), Illinois, part of its 15 year $4.5 billion modernization plan across its “organic industrial base.” The service calls it the “world’s largest additive and subtractive manufacturing apparatus” that was built as a collaborative effort between RIA-JMTC, the U.S. Army Ground Systems Center, Ingersoll Machine Tool, the Applied Science and Technology Research Organization of America and Siemens. It “could eventually build equipment the size of tank hulls with minimal use of traditional manufacturing processes,” says the Army.
