Popular Mechanics - Testing a GE36 Unducted Fan (UDF) engine, or propfan, on a Boeing 727 in the 1980s. | Facebook
![Engine makers GE and P&W race to boost efficiency as net-zero carbon goal looms | Analysis | Flight Global Engine makers GE and P&W race to boost efficiency as net-zero carbon goal looms | Analysis | Flight Global](https://d3lcr32v2pp4l1.cloudfront.net/Pictures/1024x536/2/8/2/83282_gepropfanconcept_942812.jpg)
Engine makers GE and P&W race to boost efficiency as net-zero carbon goal looms | Analysis | Flight Global
![Advanced turboprop (ATP) engines. Schematic images of a an unducted fan... | Download Scientific Diagram Advanced turboprop (ATP) engines. Schematic images of a an unducted fan... | Download Scientific Diagram](https://www.researchgate.net/publication/235060561/figure/fig2/AS:339749500932098@1458014001315/Advanced-turboprop-ATP-engines-Schematic-images-of-a-an-unducted-fan-UDF-engine-a.png)
Advanced turboprop (ATP) engines. Schematic images of a an unducted fan... | Download Scientific Diagram
![Cheap fuel killed propfan concepts decades ago. Can CFM's revived concept endure? | Analysis | Flight Global Cheap fuel killed propfan concepts decades ago. Can CFM's revived concept endure? | Analysis | Flight Global](https://d3lcr32v2pp4l1.cloudfront.net/Pictures/1024x536/7/3/7/79737_mdpropfanvariantsnasa_20041.jpg)
Cheap fuel killed propfan concepts decades ago. Can CFM's revived concept endure? | Analysis | Flight Global
![Jett Mayhem on Twitter: "@MenTourPilot Take a look at the mid to late 80's GE36 unducted fan (propfan) - The tech and concept of this 25,000 lbf thrust GE engine design is Jett Mayhem on Twitter: "@MenTourPilot Take a look at the mid to late 80's GE36 unducted fan (propfan) - The tech and concept of this 25,000 lbf thrust GE engine design is](https://pbs.twimg.com/media/EvVY1JBXAAQn99h.jpg)