Engine design has always been crucial to aviation. Geared turbofans, as their name suggests, include a gearbox as part of the mechanism. Those on the A320neo are the brainchildren of engineers at Pratt & Whitney. The firm has spent two decades and more than $10 billion developing PurePower engines. Connecting an engine’s inlet fan to the compressor and turbine in its core through a gearbox should give better fuel economy and make the engine quieter, a much needed improvement for the airline industry after decades of saturation in jet tech.