As US Army Production Engineer Mallory Smith James reported (with an excellent in-depth analysis of AM for defense production applications, published on the US Army’s official online portal), the US Army’s Aviation Turbine Engines Project Office (ATE PO) selected General Electric’s T901 turboshaft engine to replace the T700 family of engines in the H-60 Black Hawk and AH-64 Apache helicopters.
As part of the same Improved Turbine Engine Program (ITEP), the Army has also selected the T901 for their Future Vertical Lift (FVL) Future Attack Reconnaissance Aircraft (FARA) Competitive Prototype Program. The new engine is required to provide necessary additional power for the high and hot environment in which today’s aircraft platforms must operate (6,000 feet altitude and 95° Fahrenheit outside air temperature).
One of the goals of the program is to achieve 50% more power and 25% better specific fuel consumption while minimizing engine weight and cost. For this reason, GE Aviation turned to its additive manufacturing capabilities and is producing many of the engine components leveraging GE Additive‘s Direct Metal Laser Melting (DMLM) technology.
GE combined more than 50 separate parts that make up the T700 lubrication system B-sump into one component for T901, making it 20% lighter than it would have been using conventional manufacturing. Additional benefits of AM include performance improvements, enhanced geometrical complexity, as well as development and manufacturing cycle time reductions.
GE Aviation has built up significant experience with 3D printed engine components from the over 716 million flight hours on LEAP, GE9X, and GEnx jet engines that utilize up to 300 additive components. Development takes place at the Additive Technology Center in West Chester Township, Ohio, a facility that has over 90 metal AM systems and a skilled team of designers, machinists, and engineers who develop and mature manufacturing processes that are eventually turned over to GE’s additive production facilities in Cameri, Italy and Auburn, Alabama.
In 2016, GE purchased Concept Laser and Arcam AB and formed the GE Additive division. This significant investment enabled GE to exercise more control over the critical aspects of the AM supply chain. GE utilizes two different commercially available machines to manufacture T901 components for Engineering and Manufacturing Development (EMD).
Production of larger additive components in higher volumes is a growing priority for one of GE’s new commercial engines, the Catalyst, which like the T901 uses AM for large structural components. If the Catalyst program proceeds with their production transition in 2021-2022, they would produce additive components for approximately 300 engines per year at their Avio Aero (a GE Aviation business) facility in Brindisi, Italy.
The Catalyst transition to a high volume environment for large parts could benefit ITEP, as any learning from this transition would be applied to T901. The T901 engine is currently scheduled to start Low Rate Initial Production (LRIP) in Fiscal Year (FY) 2025 and Full-Rate Production (FRP) in FY 2027 with a smaller forecasted annual production rate than Catalyst.