GE Aviation Successfully Tests 3D Printed ATP Engine

Last year, GE Aviation announced that it would be undertaking quite a project. The company would be building an engine for a private plane, a Cessna Denali from Textron Aviation, that would feature multiple 3D printed parts. Over the last two years, GE Aviation has been hard at work, carrying out the first test of a demonstrator engine, containing 12 3D printed parts, last November and moving forward at a steady pace. Now the project is almost finished, as the Advanced Turboprop (ATP) Engine just passed another test last Friday.

“This is a pivotal moment. We now have a working engine. We are moving from design and development to the next phase of the program, ending with certification,” said Paul Corkery, General Manager of the Advanced Turboprop program.

More than one-third of the ATP is 3D printed from a special titanium alloy, and it’s made from just 12 parts, reduced from 855. 3D printing and several other advanced technologies allowed for the number of parts to be reduced, as well as the weight, which was reduced by more than 100 pounds. Fuel burn was improved by as much as 20 percent and power by 10 percent.

Approximately 400 designers, engineers and materials experts in the Czech Republic, Italy, Poland and the United States worked on the development of the engine. The designers included certain components in the engine’s compressor that were originally developed for supersonic engines. Called variable vanes, these parts allow the plane to fly efficiently even at high altitudes. The designers also used digital technology to develop a way to control the engine so that the plane can be flown like a jet with one lever instead of three.

“I would use the phrase ‘revolutionary simplicity,'” said Brad Thress, Senior Vice President of Engineering at Textron Aviation.

The ATP engine was assembled this fall in Prague and then moved next door to a test cell. The engine was connected to a water brake, which simulates the torque caused by the propeller, and to tubes supplying air, fuel and oil and removing exhaust. Hundreds of wires, tubes and cables were also connected, leading to sensors located in metal cabinets against the wall. The sensors gather information about torque, vibrations, thrust and other factors. Cameras around the test cell monitor for fuel and oil leaks.

Data from the sensors goes to computer servers located one floor above the cell. The servers already hold information gathered from testing individual components of the engine over the last year, such as the compressor, which was tested with the variable vanes at a special custom-built rig at the Technical University of Munich.

“We can push it to stalling point and test the entire operating range,” said GE Engineer Rudolf Selmeier.

The data obtained from the tests allowed GE to create a digital model of the engine, which can be compared with information obtained during full engine tests and used to spot problems and come up with solutions.

“It used to take us 10 years to develop a new engine,” said Materials Scientist and ATP Quality Inspector Bedrich Dolezal. “With this software and data, we can do it in two.”

GE Aviation plans to build a total of 10 ATP test engines and open five more test cells. The engines will be used to run several more tests before the engine can be certified for flight by government authorities; tests will include altitude, performance and high-vibration testing. The engine will also be tested on the wing of a flying “test bed” soon. GE plans to certify it for passenger flight within two years.

As GE continues to focus on metal additive manufacturing and invest in the technology, applications across its businesses, including GE Aviation for work on aircraft engines, will continue to advance.