August 14, 2022
Propfan Power: The Story of the Unducted Fan Engine
History Special

Propfan Power: The Story of the Unducted Fan Engine

DALLAS – The future of aviation revolves around sustainability. But building a greener, more environmentally friendly industry is nothing new.

Engine makers are a prime target for reducing aviation’s impact on the planet. As well as reducing emissions from their power plants, they must also strive to reduce fuel burn, thus reducing costs for their airline customers.

Over the years, there have been various innovative designs, one of which was the ‘Prop-fan/Unducted fan,’ also known as an ‘Open Rotor Engine.’

An Unducted Fan has a large number of highly twisted blades housed outside of the engine cowling. Photo: NASA.

Early Days

Back in the 1940s, American propeller maker Hamilton Standard looked at creating new blades so that its power plants could match the performance of the emerging turbofan/jet engines. Sadly, noise levels, blade stress, and flutter issues caused the concept to be dropped.

The crippling oil crisis of the 1970s led airlines to call upon plane makers to develop new technology to reduce their costs. Led by the US space agency NASA, teams began looking at installing a more fuel-efficient propellor that could operate at the same speed and altitude as a jet engine.

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Featured Image: McDonnell Douglas fitted both the GE36 and P&W 578-DX to an MD-80 demonstrator. Photo: Ron Kawai, Public domain, via Wikimedia Commons

Writer, aviation fanatic, plant geek and part-time Flight Attendant for a UK based airline. Based in Liverpool, United Kingdom.

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