Earlier this year we saw the first example of a 3D-printed jet engine, now GE has announced the first 3D-printed part certified by the US Federal Aviation Administration (FAA) for a commercial jet engine. The fist-sized T25 housing for a compressor inlet temperature sensor was fabricated by GE Aviation and will be retrofitted to over 400 GE90-94B jet engines on Boeing 777 aircraft.

The T25 housing is located inlet to the high-pressure compressor and protects the sensor electronics from cold and being buffeted by airflow, and is the product of a decade's experimentation in additive manufacturing. In this, the usual fabrication methods of casting or milling metal are replaced by building up a part layer by layer guided directly from a CAD file like a hobbyist's 3D printer.

The difference is that instead of making an item by adding layers of molten plastic, the T25 housing is made of a fine powder of cobalt-chrome alloy. This is spread out in a flat layer and a laser or electron beam fuses a section of the CAD plan in it. Another layer of dust is laid down and the process is repeated. When the printing is completed, the excess powder is blown and brushed away, and the part is given a finish.