When it comes to flight-critical components or components where performance is crucial if the aircraft is to operate reliably, they must receive FAA certification before they are allowed to be installed. One of the first 3D printed components to receive the certification was the LEAP fuel nozzle, which is featured in GE’s GE9X jet engine. The famed engine now contains over 300 individual 3D printed parts, including temperature sensors and fuel mixers, and larger parts, like heat exchangers, separators, and foot-long low-pressure turbine blades – all serving to save weight (and fuel) via geometric optimization.

The engine recently completed its first test flight on a Boeing 777x airliner, which is the world’s largest twin-engine jetliner and passenger plane. Two previous attempts at getting the 777X airborne were made, however, the tests were postponed due to high winds. In January of 2020, however, the airplane took off from Paine Field in Everett, WA.
Honeywell Aerospace, the aerospace division of conglomerate Honeywell, also recently received an FAA certification for one such 3D printed component. The part in question – a #4/5 bearing housing – is a key structural component of the ATF3-6 turbofan engine found in the Dassault Falcon 20G maritime patrol aircraft. The part is already in production and has been installed in an operational Falcon unit, with dozens more expected to be printed by the end of the year.

Over in academia, Auburn University’s National Center for Additive Manufacturing Excellence (NCAME) recently received a $3M grant from the FAA, which it will use to commence a two-year research project to improve air travel. Specifically, the NCAME engineers will delve deeper into metal 3D printing and its materials to fine-tune the parameters required to print end-use components for commercial aircraft.

Under the hood, the Auburn project is ultimately intended to solve a core issue in additive manufacturing, which is variability in performance. Variability results in identical parts 3D printed on different machines having discrepancies in their mechanical properties. According to the NCAME, there is also a lack of understanding when it comes to the microstructures of 3D printed metal parts, and their subsequent effects on fatigue and fracture resistance. This makes it very difficult to define specifications and standards in the industry – especially with tightly controlled parts for sectors such as aviation.

3D printing polymers for aviation