A 3D-printed full-scale model of the GE T901 engine hangs from a sling in the Boeing-Mesa facility during a mock-up Fit Check in an Apache helicopter. Photo Credit: The Boeing Company; GE Aviation; Aviation Turbine Engines Project Office
A 3D-printed full-scale model of the GE T901 engine hangs from a sling in the Boeing-Mesa facility during a mock-up Fit Check in an Apache helicopter. Photo Credit: The Boeing Company; GE Aviation; Aviation Turbine Engines Project Office (Photo Credit: MIKE GOETTINGS) VIEW ORIGINAL

As the U.S. Army continues to modernize, improving Army aviation is one of its top priorities. One of the key supporting efforts is the development of a new turbine engine to provide next-generation power to the chosen Future Attack Reconnaissance Aircraft (FARA) aircraft and the enduring Apache and Black Hawk fleets.

Program Executive Office, Aviation’s Aviation Turbine Engine Project Office is responsible for developing the new Improved Turbine Engine (ITE). One of the first decisions made by the design team was to incorporate Additive Manufacturing (AM) from the beginning of the program.

The Improved Turbine Engine Program (ITEP) is the one of the first programs in military aviation to understand the importance of AM and include AM in the earliest stages of the engine design process. The ITEP is an example of how to leverage AM from the early stages of designing and developing new technologies to deliver long-term performance, reliability, maintainability, and cost savings benefits.

Additive Manufacturing joins powders, liquids or plastics together based on digital models to produce three-dimensional parts. AM enables significant component piece part reduction and improved reliability while reducing cost and weight. Additional benefits of AM include performance improvements, enhanced geometrical complexity, as well as development and manufacturing cycle time reductions.

In February 2019, the Improved Turbine Engine Program selected General Electric’s T901 turboshaft engine to be the ITE. With a 3,000 shaft horsepower engine, the ITE will power the Future Attack Reconnaissance Aircraft (FARA) platform, and is key to improving Black Hawk and Apache fleets’ range, payload, and loiter time over the current 701D engine. The ITEP will also increase lethality by creating the capability to operate with full mission payloads in high hot (6k/95 degrees) environments, reducing fuel consumption, and improving both reliability and maintainability.

Mallory Smith James, an ITEP Production Engineer recently published Additive Manufacturing and the U.S. Army’s Improved Turbine Engine (2020. In the paper, James explores how ITEP has paved the way for new programs to incorporate AM at the earliest stages in the design and development of new systems. She also offers a summarized history of development of AM for Aviation, and discusses why the Army can benefit from ITEP’s lessons learned to better leverage AM in future programs.

As one of the first programs to integrate AM from the earliest phases of design and development, ITEP adopted AM before many third party standards or specifications were available. Based on ITEP’s experiences, James explains how future uses of AM will benefit as AM standards continue to mature which can aide in technical oversight as well as supplement industry counterparts’ privately developed standards and specifications.

Continued maturation of AM technology is also critical, particularly the development of multi-laser machines and in-situ process monitoring, to ensure affordability of AM in a production environment. The T901 will help push the development of AM which Eric Gatlin, general manager for GE Aviation’s Additive Integrated Product Team, elaborated on with, “The components that we are working on for T901 are driving us to advance state-of-the-art in AM design, development, and manufacturing processes.” The benefits of AM increase when it is included into a product’s design from the beginning, such as in the ITEP. Engineers can use AM as they design parts to influence component design, interaction, and how they will be maintained or repaired.

AM can create opportunities to reduce the number of parts needed or to change how a part is built to increase function, reduce weight, or increase strength or flexibility. The flexibilities provided by AM create opportunities for savings in cost, maintenance, and supply logistics. Design teams can also leverage AM in unique ways to streamline development and integration of a new technology into an existing platform. For example, the ITEP used a 3D-printed full-scale model of the GE T901 engine to complete mock-up Fit Checks in an Apache and Black Hawk to assess the form, fit, and Human Systems Integration of the GE T901 as an Integration Risk Reduction Effort. AM also offers reduced cycle times and new supply chain availability for historically difficult to source components.

Prior to ITEP, retroactively applying AM manufacturing techniques to enduring systems components was the most common use of this developing technology and is a practice that continues to grow. However, adapting older systems for additive manufacturing may be heavily constrained by existing design features like envelope and interface requirements, funding constraints, or program schedules. In enduring aviation systems, a significant change in manufacturing process requires component redesign, validation and flight qualification efforts in order to adapt the technology to older designs which may consume precious time and funding.

Continued engagement and investment in research and development activities with academia, other government agencies, and industry will enable AM standards to mature and develop the technology needed for the DOD achieve its AM goals for emerging and enduring systems. Necessary engagement includes greater investment in government-led, hands-on projects on design for AM, material characterization, machine capabilities, and post-processing techniques, which would put government engineers on equal footing with their industry and academic counterparts and better inform oversight of industry’s additive manufacturing processes. James speaks to the continued growth of AM during her career with, “One of the highlights of my job has been learning all I can about this cutting edge technology and how it will set ITEP apart from military aviation programs that have come before it. While the newness of additive certainly brings its share of challenges to solve, there is a growing community of experts in additive manufacturing, including our partners with GE Aviation, the Army’s Aviation ManTech group, experts in academia, and countless others.”

 In the James full white, the benefits of fostering essential talent in AM through opportunities to immerse Army engineers in AM, increasing emphasis on the value of incorporating AM early in the design, and the development of new systems is explored alongside ITEP’s lessons learned. It is through these essential first-hand experiences, hands-on projects, and partnerships, the Army will build its greatest asset to better understand and leverage AM: its people.

See the full Additive Manufacturing and the U.S. Army’s Improved Turbine Engine (2020) white paper by Mallory Smith James https://www.army.mil/article/248519